Staff

Abstract:
Efficient and sustainable energy conversion depends on the rational design of single-atom catalysts. The control of the active sites at the atomic level is vital for electrocatalytic materials in alkaline and acidic electrolytes. Moreover, fabrication of effective catalysts with a well-defined surface structure results in an in-depth understanding of the catalytic mechanism. Herein, a single atom ruthenium dispersed in nickel-cobalt layered hydroxide (Ru-NiCo LDH) is reported. Through the precise controlling of the atomic dispersion and local coordination environment, Ru-NiCo LDH//Ru-NiCo LDH provides an ultra-low overpotential of 1.45 mV at 10 mA cm−2 for the overall water splitting, which surpasses that of the state-of-the-art Pt/C/RuO2 redox couple. Density functional theory calculations show that Ru-NiCo LDH optimizes hydrogen evolution intermediate adsorption energies and promotes O-O coupling at a Ru-O active site for oxygen evolution, while Ni serves as the water dissociation site for effective water splitting. As a potential model, Ru-NiCo LDH shows enhanced water splitting performance with potential for the development of promising water-alkaline catalysts.

Abstract:
The major hindrance to efficient electrocatalytic hydrogen generation from water electrolysis is the sluggish kinetics with corresponding large overvoltage of oxygen evolution reaction. Herein, we report a defective 2D NiCoMoS@Ni(CN)2 core-shell heterostructure derived from Hofmann-type MOF as an efficient and durable high-performance noble metal-free electrocatalyst for hydrazine oxidation reaction (HzOR) in alkaline media. The sluggish oxygen evolution reaction was replaced with a more thermodynamically favourable HzOR, enabling energy-saving electrochemical hydrogen production with 2D NiCoMoS@Ni(CN)2 acting as a bifunctional electrocatalyst for anodic HzOR and cathodic hydrogen generation. Operating at room temperature, the two-electrode electrolyzer delivers 100 mA cm−2 from a cell voltage of just 257 mV, with strong long-term electrochemical durability and nearly 100% Faradaic efficiency for hydrogen evolution in 1.0 M KOH aqueous solution with 0.5 M hydrazine. The density functional theory (DFT) was employed to investigate the origin of catalytic performance and showed that high vacancy creation within the heterointerface endowed NiCoMoS@Ni(CN)2 with favourable functionalities for excellent catalytic performance.

Keywords:
Defect engineering, Core-shell, Electrocatalyst, Hydrazine oxidation, Heterostructure

Abstract:
The slow photon effect in inverse opal photonic crystals
represents a promising approach to manipulate the interactions
between light and matter through the design of material
structures. This study introduces a novel ordered inverse opal
photonic crystal (IOPC) sensitized with perovskite quantum dots
(PQDs), demonstrating its efficacy for efficient visible-lightdriven
H2 generation via water splitting. The rational structural
design contributes to enhanced light harvesting. The sensitization
of the IOPC with PQDs improves optical response performance
and enhances photocatalytic H2 generation under visible
light irradiation compared to the IOPC alone. The designed
photoanode exhibits a photocurrent density of 3.42 mAcm

Keywords:
Hydrogen production, inverse opals, perovskite, quantum dots, photocatalysts, photonic crystals

Abstract:
This study showed that a polylactide (PLA)-based composite filled with nanostructured hydroxyapatite (HAp) and a natural extract from the rhizome of Curcuma longa L. could provide an alternative to commonly used fossil-based plasticsfor food packaging. The incorporation of HAp into the PLA matrix had a positive effect on improving selected properties of the composites; the beneficial effect could be enhanced by introducing a green modifier in the form of an extract. Prior to the fabrication of the composite, the filler was characterized in terms of morphology and composition, and the composite was then fully characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman and Fourier transform infrared spectroscopy (FT-IR), and the mechanical, thermal, thermomechanical, and optical properties were investigated. The proposed material exhibits antioxidant properties against DPPH radicals and antibacterial performance against Escherichia coli (E. coli). The results showed that the nanocomposite has the highest antioxidant and antibacterial properties for 10 wt% HAp with an average diameter of rod-shaped structures below 100 nm. In addition, the introduction of turmeric extract had a positive effect on the tensile strength of the nanocomposites containing 1 and 5% HAp. As the resulting material adsorbs light in a specific wavelength range, it can be used in the medical sector, food-packaging, or coatings.

Keywords:
polylactide, hydroxyapatite, turmeric extract, curcumin extract, green composite

Abstract:
Photocatalytic CO2 reduction has emerged as a promising strategy for converting solar energy into valuable chemicals, capturing the attention of scientists across various disciplines. Organic and inorganic perovskites, particularly methylammonium lead bromide (MAPbBr3), have demonstrated potential in this field due to their remarkable visible-light response and carrier transport properties. However, the catalytic performance of pristine MAPbBr3 has been limited by severe charge recombination, hindering its applicability in photocatalytic systems. Here, we show that a MAPbBr3/Bi2WO6 (MA/BWO) heterojunction significantly enhances photocatalytic CO2 reduction performance compared to individual pristine MA or BWO. This enhancement is evidenced by the superior performance of the 25% MA/BWO composite, which exhibits CO and CH4 release rates of 1.82 μmol/g/h and 0.08 μmol/g/h, respectively. This improvement is attributed to the direct Z-scheme heterojunction formed between MAPbBr3 and Bi2WO6, which facilitates efficient charge separation and suppresses charge recombination. The results challenge the previous understanding of MAPbBr3-based photocatalysts and demonstrate a novel approach for developing highly active organic and inorganic perovskite photocatalysts. The successful application of the MA/BWO heterojunction in photocatalytic CO2 reduction expands the scope of organic and inorganic perovskites in the field of renewable energy conversion. By providing a broader perspective, our findings contribute to the ongoing efforts towards sustainable energy solutions, appealing

Abstract:
This work presents the synthesis and characterization of a composite made of superparamagnetic iron oxide and hydroxyapatite nanoparticles (SPION/HAp) with a well-developed surface for loading anticancer drugs and for use in magnetic hyperthermia and local chemotherapy. The proposed material was obtained by an easy one-pot co-precipitation method with a controlled ratio of SPION to HAp. The morphology was studied by SEM and TEM, indicating rod-like structures for high HAp content in the composite and granule-like structures with increasing SPION. Its crystallinity, elemental composition, and functional groups were determined by X-ray diffraction, EDS, and FT-IR, respectively. The nanocomposite was then stabilized with citrates (CA), polyethylene glycol (PEG), and folic acid (FA) as agents to improve intracellular absorption, while turbidimetric studies confirmed that only citrates effectively stabilized the magnetic carriers to form a colloidal suspension. Subsequently, 5-fluorouracil (5-FU) was loaded into the magnetic carriers and tested in vitro using the L-929 cell line. The studies showed no cytotoxicity of the citrate-stabilized suspension against fibroblasts and some cytotoxicity after 5-FU release. In addition to in vitro studies, the composite was also tested on biomimetic membranes made of DOPC, DOPE, cholesterol, and DOPS lipids using Langmuir trough. The results show that the resulting suspension interacts with biomimetic membranes, while magnetic hyperthermia studies confirm effective heat generation to achieve therapeutic 42–46 °C and improve drug release from magnetic carriers.

Keywords:
SPION, Hydroxyapatite, Magnetic hyperthermia, Drug delivery, 5-fluorouracil, Biomimetic membranes, Nanostructures, Cancer treatment

Abstract:
Transparent electrodes are vital for optoelectronic devices, but their development has been constrained by the limitations of existing materials such as indium tin oxide (ITO) and newer alternatives. All face issues of robustness, flexibility,conductivity, and stability in harsh environments. Addressing this challenge, we developed a flexible, low-cost titanium nitride (TiN) nanomesh transparent electrode showcasing exceptional acid−alkali resistance. The TiN nanomesh electrode, created by depositing a TiN coating on a naturally cracked gel film substrate via a sputtering method, maintains a stable electrical performance through thousands of bending cycles. It exhibits outstanding chemical stability, resisting strong acid and alkali corrosion, which is a key hurdle for current electrodes when in contact with acidic/alkaline materials and solvents during device fabrication. This, coupled with superior light transmission and conductivity (88% at 550 nm with a sheet resistance of ∼200 Ω/sq), challenges the reliance on conventional materials. Our TiN nanomesh electrode,successfully applied in electric heaters and electrically controlled thermochromic devices, offers broad potential beyond harsh environment applications. It enables alternative possibilities for the design and fabrication of future optoelectronics for advancements in this pivotal field.

Keywords:
transparent electrode, titanium nitride, flexible, corrosion resistant, mesh, smart window

Abstract:
The rapidly growing production and usage of lithium-ion batteries (LIBs) dramatically raises the number of harmful wastes. Consequently, the LIBs waste management processes, taking into account reliability, efficiency, and sustainability criteria, became a hot issue in the context of environmental protection as well as the scarcity of metal resources. In this paper, we propose for the first time a functional material—a magnetorheological fluid (MRF) from the LIBs-based liquid waste containing heavy metal ions. At first, the spent battery waste powder was treated with acid-leaching, where the post-treatment acid-leaching solution (ALS) contained heavy metal ions including cobalt. Then, ALS was used during wet co-precipitation to obtain cobalt-doped superparamagnetic iron oxide nanoparticles (SPIONs) and as an effect, the harmful liquid waste was purified from cobalt. The obtained nanoparticles were characterized with SEM, TEM, XPS, and magnetometry. Subsequently, superparamagnetic nanoparticles sized 15 nm average in diameter and magnetization saturation of about 91 emu g−1 doped with Co were used to prepare the MRF that increases the viscosity by about 300% in the presence of the 100 mT magnetic fields. We propose a facile and cost-effective way to utilize harmful ALS waste and use them in the preparation of superparamagnetic particles to be used in the magnetorheological fluid. This work describes for the first time the second life of the battery waste in the MRF and a facile way to remove the harmful ingredients from the solutions obtained after the acid leaching of LIBs as an effective end-of-life option for hydrometallurgical waste utilization.

Keywords:
environment protection SPION, battery waste, toxic waste management, direct recycling, sustainability, circular economy, critical raw materials

Abstract:

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Open AccessArticle
Oxidative Stress in Long-Term Exposure to Multi-Walled Carbon Nanotubes in Male Rats
by Ewa Florek
1,* [ORCID] , Marta Witkowska
2,3, Marta Szukalska
1 [ORCID] , Magdalena Richter
4 [ORCID] , Tomasz Trzeciak
4, Izabela Miechowicz
5 [ORCID] , Andrzej Marszałek
6 [ORCID] , Wojciech Piekoszewski
7 [ORCID] , Zuzanna Wyrwa
1 and Michael Giersig
3,8
1
Laboratory of Environmental Research, Department of Toxicology, Poznan University of Medical Sciences, 60-631 Poznan, Poland
2
Faculty of Chemistry, Adam Mickiewicz University, 61-614 Poznan, Poland
3
Centre for Advanced Technologies, Adam Mickiewicz University, 61-614 Poznan, Poland
4
Department of Orthopedics and Traumatology, Poznan University of Medical Sciences, 61-545 Poznan, Poland
5
Department of Computer Science and Statistics, Poznan University of Medical Sciences, 60-806 Poznan, Poland
6
Oncologic Pathology and Prophylaxis, Greater Poland Cancer Centre, Poznan University of Medical Sciences, 61-866 Poznan, Poland
7
Department of Analytical Chemistry, Faculty of Chemistry, Jagiellonian University, 30-387 Krakow, Poland
8
Department of Theory of Continuous Media and Nanostructures, Institute of Fundamental Technological Research, Polish Academy of Sciences, 02-106 Warsaw, Poland
*
Author to whom correspondence should be addressed.
Antioxidants 2023, 12(2), 464; https://doi.org/10.3390/antiox12020464
Received: 13 December 2022 / Revised: 7 February 2023 / Accepted: 10 February 2023 / Published: 12 February 2023
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Abstract
Multi-walled carbon nanotubes (MWCNTs) serve as nanoparticles due to their size, and for that reason, when in contact with the biological system, they can have toxic effects. One of the main mechanisms responsible for nanotoxicity is oxidative stress resulting from the production of intracellular reactive oxygen species (ROS). Therefore, oxidative stress biomarkers are important tools for assessing MWCNTs toxicity. The aim of this study was to evaluate the oxidative stress of multi-walled carbon nanotubes in male rats. Our animal model studies of MWCNTs (diameter ~15–30 nm, length ~15–20 μm) include measurement of oxidative stress parameters in the body fluid and tissues of animals after long-term exposure. Rattus Norvegicus/Wistar male rats were administrated a single injection to the knee joint at three concentrations: 0.03 mg/mL, 0.25 mg/mL, and 0.5 mg/mL. The rats were euthanized 12 and 18 months post-exposure by drawing blood from the heart, and their liver and kidney tissues were removed. To evaluate toxicity, the enzymatic activity of total protein (TP), reduced glutathione (GSH), glutathione S–transferase (GST), thiobarbituric acid reactive substances (TBARS), Trolox equivalent antioxidant capacity (TEAC), nitric oxide (NO), and catalase (CAT) was measured and histopathological examination was conducted. Results in rat livers showed that TEAC level was decreased in rats receiving nanotubes at higher concentrations. Results in kidneys report that the level of NO showed higher concentration after long exposure, and results in animal serums showed lower levels of GSH in rats exposed to nanotubes at higher concentrations. The 18-month exposure also resulted in a statistically significant increase in GST activity in the group of rats exposed to nanotubes at higher concentrations compared to animals receiving MWCNTs at lower concentrations and compared to the control group. Therefore, an analysis of oxidative stress parameters can be a key indicator of the toxic potential of multi-walled carbon nanotubes.

Keywords:
multi-walled carbon nanotubes,oxidative stress parameters,rats,long-term toxicity

Abstract:
Two-dimensional polystyrene sphere opals are important materials for nanotechnology applications and fundamental nanoscience research. They are a facile and inexpensive nanofabrication tool, but the quality factor of these opals has drastic differences between reports. Additives like ethanol, ions, and organic molecules in the aqueous particle spreading solution are known to affect the quality factor and growth efficiency of the produced opals. However, a systematic study on the effect and optimization of some of the most effective additives has not been reported until now. Here, we investigate the influence of additives on the growth efficiency and quality factor of such monolayers formed at the air−water interface without the use of a Langmuir−Blodgett trough. The additives induced large variations in the monolayer quality factor and growth efficiency, and we found that the ideal additive content of the spreading agents is 30 wt % < cethanol < 70 wt %, 0 < cHd 2SOd 4 < 30.5 mM, and 0 < csty < 255.0 mM. This study provides a guideline for the rational composition and additive content of the spreading solution to obtain high-quality two-dimensional opals for further applications in nanofabrication and photonics and will enable researchers and application engineers to produce standardized nanofabrication materials.

Keywords:
hydroxyapatite, myo-inositol, 5-fluorouracil, anticancer treatment, SKOV-3, calendula extract, Langmuir trough

Keywords:
Spent lithium-ion batteries, LiBs, Acid leaching, SPION, Magnetic nanomaterials, Metals recovery, Superparamagnetic, Waste management, Functional materials

Keywords:
Drug delivery, Hydroxyapatite, Anticancer, 5-fluorouracil, Curcuminoids, Nanocomposite

Keywords:
Magnetorheological Fluids (MRF), rheology, smart materials, intelligent fluid, functional materials

Abstract:
The integration of different precursor components to form single nanostructures via one-step synthesis process is mostly restricted by the compatibility and complexity of components. Herein, a highly uniform, spherical, hollowed, and hierarchical iron oxide-wrapped Mo–polydopamine is synthesized using a one-pot liquid-phase reaction at room temperature. Mo2C is doped with Fe3O4 to harness the rich electrons in Fe dopants for effective lowering of the unoccupied d-orbitals in Mo. The surface conductivity of the as-prepared nanostructures is enhanced by decorating them with gold nanoparticles utilizing strong interaction of Au and amine. The nanocomposites are converted into carbidic hollowed structures via an annealing process without any distortion in morphology. The well-organized structure and nanosize of the particles provide efficient catalytic performance for hydrogen evolution reaction in acidic media. MoFe–C@Au exhibits a very positive onset potential of 2 mV, low Tafel slope of 50.1 mV dec^-1, and remarkable long- term stability.

Keywords:
electrocatalysts,hierarchical syntheses,hydrogen evolution,molybdenum,polydopamine

Abstract:
Plasma-treated polystyrene particles (PSP) are key building blocks in the fabrication of two- dimensional nanostructure arrays. Oxygen plasma etching can shrink PS particles and is a widespread tool in fundamental research and applications, but its effect has not been well understood. Here, we show that oxygen plasma induces an ultra-thin cross-linking layer on the surface of the PSPs, which increases their solvent resistance. We found in X-ray photoelectron spectroscopy (XPS) fine structure and valence band probing that the polymer C–C bonds are breaking and ecombining to form oxygenated functional groups. Our results explain, why oxygen plasma etched PS particles are more difficult to dissolve in nanofabrication procedures. Further, we used the ultra-thin crosslinked polymer layer to construct novel substrate-base microcavity arrays.

Keywords:
Polystyrene particle, Oxygen plasma, Cross-linking

Keywords:
Nanostructural hydroxyapatite, Apatite ore, Wastewater treatment, Heavy metal ions removal, Novel eco-friendly adsorbent, Adsorption

Abstract:
A simple and inexpensive method for the controlled loading of silica particles with dyes and nanocrystals is presented. Polydiallyldimethylammonium chloride is used as a positively charged bridge to facilitate electrostatic adsorption of negatively charged dyes onto negatively charged silica microspheres. The particles are subsequently coated with a further silica shell to protect the dyes against chemical degradation and leakage and this shell affords a unform particle surface independent of its doping. This encapsulation method is highly versatile and can be extended to doping with semiconductor nanocrystals, which we demonstrate using CdSe/ZnS core/shell quantum dots. The synthesis steps and end products are characterized with electron microscopy, optical spectroscopy and the electrokinetic potential of the colloidal suspensions. We show that the particles adapt the optical properties of their dopants and are resistant to degradation, dopant leakage and show reasonable emission even at acidic pH values due to the protective shell.

Keywords:
Silica particles, Dye, Quantum dot, Polydiallyldimethylammonium chloride, Doping

Abstract:
The global pandemic of COVID-19 is an example of how quickly a disease-causing virus can take root and threaten our civilization. Nowadays, ultrasensitive and rapid detection of contagious pathogens is in high demand. Here, we present a novel hierarchically porous 3-dimensional magnetic molybdenum trioxide–polydopamine-gold functionalized nanosphere (3D mag-MoO3–PDA@Au NS) composed of plasmonic, semiconductor, and magnetic nanoparticles as a multifunctional nanosculptured hybrid. Based on the synthesized 3D mag-MoO3–PDA@Au NS, a universal “plug and play” biosensor for pathogens is proposed. Specifically, a magnetically-induced nanogap-enhanced Raman scattering (MINERS) detection platform was developed using the 3D nanostructure. Through a magnetic actuation process, the MINERS system overcomes Raman signal stability and reproducibility challenges for the ultrasensitive detection of SARS-CoV-2 spike protein over a wide dynamic range up to a detection limit of 10−15 g mL−1. The proposed MINERS platform will facilitate the broader use of Raman spectroscopy as a powerful analytical detection tool in diverse fields.

Abstract:
Enhancing the selectivity of hydrocarbon products remains a key challenge to achieving artificial energy sustainability via closing the carbon cycle. While copper-based electrodes uniquely yield hydrocarbon products, the improvement of their product selectivity through physical morphology regulation shows great potential and requires further investigation. Here, we show the distinct morphological influences of the Cu electrode on the reaction selectivity. We synthesize binder-free, vertically aligned, nanoid forest-like copper electrocatalysts for superior improved methane conversion selectivity with respect to planar Cu. These Cu nanocomposites are fabricated through the conformal coating of vertically aligned multiwalled carbon nanotube array electrodes, which have matured to a cost-effective and scalable technology over the past two decades. Simulations reveal that carbon intermediates and protons can be confined in the gaps of the nanoid copper forest, which are formed in situ and in turn cover the catalytic sites and facilitate the simultaneous transfer of coupled electrons and protons. Such forest-like antenna morphology benefits from a threefold improvement of the CO2 electroreduction performance through a decreased reaction onset potential, an increased current density, and enhanced hydrocarbon selectivity.

Keywords:
CO2 conversion,electroreduction,MWCNT,copper catalyst

Abstract:
In this work, we present magnetic nanoparticles based on iron oxide doped with zinc syn-
thesized using the wet co-precipitation method for environmental application. The morphology of the
samples was revealed by SEM and TEM, which showed particles of granular shape and size of about
15 nm. The specific surface areas of the materials using the BET method were within the range of 85.7 to 101.5 m2 g−1 depending on the zinc content in the superparamagnetic iron oxide nanoparticles (SPI-ONs). Magnetometry was performed to determine the magnetic properties of the particles, indicating superparamagnetism. Synthesized magnetic nanoparticles with different amounts of zinc dopant were used as an adsorbent to remove model pollutant Titan yellow (TY) from the aqueous solutions. Adsorption was determined by investigating the effects of sorbent amount, dye concentration, and contact time. The synthesized material removed Titan yellow quickly and efficiently within the phys-ical adsorption. The adsorption isotherms were consistent with the models proposed by Langmuir and Redlich-Peterson. The monolayer adsorption capacities were 30 and 43 mg g−1 for Fe3O4 and Fe3O4@10%Zn, respectively, for the removal of TY. However, that of Congo red is 59 mg g−1 by Fe3O4@10%Zn. The proposed nanoparticles offer fast and cost-effective water purification, and they can be separated from solution using magnets.

Keywords:
perparamagnetic particles, pollution treatment, Titan yellow, Congo red, adsorption isotherm, iron oxide

Abstract:
In this work, we report on the fabrication of nanocomposites based on superparamagnetic iron oxide nanoparticles (SPIONs) in combination with hydroxyapatite (HAp) as a platform for drug delivery and magnetic hyperthermia application. First, the influence of experimental conditions such as co-precipitant, bath temperature, and pH on the morphology and magnetic properties of SPIONs was investigated. Then, the superparamagnetic particles were coated with the hydroxyapatite layer for further loading of anticancer drugs, determining the optimal thickness of the HAp shell. The composite was fabricated by the wet chemical process and was characterized by optimizing the experimental conditions of the wiring synthesis to obtain the superparamagnetic spherical material with a high HAp loading as a platform for drug uptake. SEM and TEM studies confirmed the round shape of the magnetic core up to 15 nm in size with a well-defined HAp shell. After checking the material’s superparamagnetic properties, the temperature dependence on time and alternating magnetic field strength was tested and optimized in hyperthermia experiments.

Keywords:
superparamagnetic iron oxide nanoparticles (SPIONs), hydroxyapatite, nanocomposite, magnetic hyperthermia

Abstract:
Reinforced concrete based on ordinary Portland cement (OPC) is one of the most commonly used materials in modern buildings. Due to the global growth of the building industry, concrete components have been partially or completely replaced with waste materials that can be used as binders or aggregates. Besides the ecological aspects, modern architecture widely needs materials to make the concrete durable, resisting large loads and various detrimental forces in the environment. This opens the possibilities of managing waste materials and applying them in practice. This paper presents a concise review of the green solutions for ecofriendly materials in the building industry that deal with the practical application of materials commonly treated as waste. The main emphasis was placed on their influence on the properties of the building material, optimal composition of mixtures, and discussion of the advantages and disadvantages of each of the “green” additives. It turned out that some solutions are far from being ecofriendly materials, as they leech and release numerous harmful chemicals into the environment during their presence in concrete. Finally, the paper suggests a research direction for the development of an ecofriendly structural material for a sustainable future.

Keywords:
green concrete; waste management; waste as a cement filler; secondary raw materials; alternative cements

Abstract:
Chains of alternating semiconductor nanocrystals are complex nanostructures that can offer control over photogenerated charge carriers dynamics and quantized electronic states. We develop a simple one-pot colloidal synthesis of complex Cu1.94S-CdS and Cu1.94S-ZnS nanochains exploiting an equilibrium driving ion exchange mechanism. The chain length of the heterostructures can be tuned using a concentration dependent cation exchange mechanism controlled by the precursor concentrations, which enables the synthesis of monodisperse and uniform Cu1.94S-CdS-Cu1.94S nanochains featuring three epitaxial junctions. These seamless junctions enable efficient separation of photogenerated charge carriers, which can be harvested for photocatalytic applications. We demonstrate the superior photocatalytic activity of these noble metal free materials through solar hydrogen generation at a hydrogen evolution rate of 22.01 mmol g–1 h–1, which is 1.5-fold that of Pt/CdS heterostructure photocatalyst particles.

Abstract:
Photoelectrochemical devices integrate the processes of light absorption, charge separation, and catalysis for chemical synthesis. The monolithic design is interesting for space applications, where weight and volume constraints predominate. Hindered gas bubble desorption and the lack of macroconvection processes in reduced gravitation, however, limit its application in space. Physico-chemical modifications of the electrode surface are required to induce gas bubble desorption and ensure continuous device operation. A detailed investigation of the electrocatalyst nanostructure design for light-assisted hydrogen production in microgravity environment is described. p-InP coated with a rhodium (Rh) electrocatalyst layer fabricated by shadow nanosphere lithography is used as a model device. Rh is deposited via physical vapor deposition (PVD) or photoelectrodeposition through a mask of polystyrene (PS) particles. It is observed that the PS sphere size and electrocatalyst deposition technique alter the electrode surface wettability significantly, controlling hydrogen gas bubble detachment and photocurrent–voltage characteristics. The highest, most stable current density of 37.8 mA cm−2 is achieved by depositing Rh via PVD through 784 nm sized PS particles. The increased hydrophilicity of the photoelectrode results in small gas bubble contact angles and weak frictional forces at the solid–gas interface which cause enhanced gas bubble detachment and enhanced device efficiency.

Keywords:
electrocatalyst nanotopography, hydrogen evolution, microgravity, photoelectrocatalysis, (photo-)electrochemical gas bubble evolution, shadow nanosphere lithography

Abstract:
Until now, the growth of periodic vertically aligned multi-walled carbon nanotube (VA-
MWCNT) arrays was dependent on at least one lithography step during fabrication. Here, we demonstrate a lithography-free fabrication method to grow hexagonal arrays of self-standing VA-MWCNTs with tunable pitch and MWCNT size. The MWCNTs are synthesized by plasma enhanced chemical vapor deposition (PECVD) from Ni catalyst particles. Template guided dewetting of a thin Ni film on a hexagonally close-packed silica particle monolayer provides periodically distributed Ni catalyst particles as seeds for the growth of the periodic MWCNT arrays. The diameter of the silica particles directly controls the pitch of the periodic VA-MWCNT arrays from 600 nm to as small as 160 nm. The diameter and length of the individual MWCNTs can also be readily adjusted and are a function of the Ni particle size and PECVD time. This unique method of lithography-free growth of periodic VA-MWCNT arrays can be utilized for the fabrication of large-scale biomimetic materials

Keywords:
periodic, ithography free, nanofabrication, template guided, vertically-aligned multi- walled carbon nanotubes, self-standing

Abstract:
Melanin nanoparticles are known to be biologically benign to human cells for a wide range of concentrations in a high glucose culture nutrition. Here, we show cytotoxic behavior at high nanoparticle and low glucose concentrations, as well as at low nanoparticle concentration under exposure to (nonionizing) visible radiation. To study these effects in detail, we developed highly monodispersed melanin nanoparticles (both uncoated and glucose-coated). In order to study the effect of significant cellular uptake of these nanoparticles, we employed three cancer cell lines: VM-M3, A375 (derived from melanoma), and HeLa, all known to exhibit strong macrophagic character, i.e., strong nanoparticle uptake through phagocytic ingestion. Our main observations are: (i) metastatic VM-M3 cancer cells massively ingest melanin nanoparticles (mNPs); (ii) the observed ingestion is enhanced by coating mNPs with glucose; (iii) after a certain level of mNP ingestion, the metastatic cancer cells studied here are observed to die—glucose coating appears to slow that process; (iv) cells that accumulate mNPs are much more susceptible to killing by laser illumination than cells that do not accumulate mNPs; and (v) non-metastatic VM-NM1 cancer cells also studied in this work do not ingest the mNPs, and remain unaffected after receiving identical optical energy levels and doses. Results of this study could lead to the development of a therapy for control of metastatic stages of cancer.

Keywords:
melanoma, melanin nanoparticles, cytotoxicity, laser medical applications, hyperthermia

Abstract:
Colloidal synthesis of photocatalysts with potential to overcome the drawback of low photocatalytic efficiency brought by charge recombination and narrow photo-response has been a challenge. Herein, a general and facile colloidal approach to synthesize orthorhombic phase Bi2S3 particles with rod and flower-like morphology is reported. We elucidate the formation and growth process mechanisms of these synthesized nanocrystals in detail and cooperate these Bi2S3 particles with metallic gold nanoparticles (AuNPs) to construct heterostructured photocatalysts. The unique properties of AuNPs featuring tunable surface plasmon resonance and large field enhancement are used to sensitize the photocatalytic activity of the Bi2S3 semiconductor particles. The morphology, structure, elemental composition, and light absorption ability of the prepared catalysts are characterized by (high-resolution) transmission electron microscopy, scanning electron microscopy, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, and UV–vis absorption spectroscopy. The catalysts exhibit high and stable photocatalytic activity for the degradation of organic pollutants demonstrated using rhodamine B and methyl orange dyes under solar light irradiation. We show that the incorporation of the AuNPs with the Bi2S3 particles increases the photocatalytic activity 1.2 to 3-fold. Radical trapping analysis indicates that the production of hydroxyl and superoxide radicals are the dominant active species responsible for the photodegradation activity. The photocatalysts exhibit good stability and recyclability.

Keywords:
Bi2S3, nanoflower, nanorod, photocatalysis, heterostructures, AuNPs

Abstract:
We propose a simple and inexpensive SiO2 submicron particle synthesis method based on a PTFE helical capillary microreactor. The device is based on Dean flow mediated, ultrafast mixing of two liquid phases in a microfluidic spiral pipe. Excellent control of particle size between 100 nm and 600 nm and narrow polydispersity can be achieved by controlling the device and process parameters. Numerical simulations are performed to determine the optimal device dimensions. In the mother liquor the silica particles exhibit zeta potentials < -60 mV, rendering them very stable even at high particle volume fractions. The current device typically produces around 0.234 g/h of the silica particles.

Keywords:
SiO2 particle synthesis, continuous flow synthesis, helical capillary microreactor

Abstract:
Semiconducting ternary metal oxide thin films exhibit a promising application for solarenergy conversion. However, the efficiency of the conversion is still limited by a band gapof a emiconductor, which determines an obtainable internal photovoltage for solar watersplitting. In this report the tunability of the tin tungstate band gap by O2 partial pressurecontrol in the magnetron co-sputtering process is shown. A deficiency in the Sn concentration increases the optical band gap of tin ungstate thin films. The optimum band gap of 1.7 eV for tin tungstate films is achieved for a Sn to W ratio at unity, which establishes thehighest photoelectrochemical activity. In particular, a maximum photocurrent density of 0.375 mA cm^2 at 1.23 VRHE and the lowest reported onset potential of -0.24 VRHE for SnWO4 thin films without any co-catalyst are achieved. Finally, we demonstrate that a Ni protection layer on the SnWO4 thin film enhances the photoelectrochemical stability, which isof paramount importance for application.

Keywords:
thin film, tin tungstate, reactive magnetron sputtering, photocurrent density, thickness band gap

Abstract:
Cartilage and bone injuries are prevalent ailments, affecting the quality of life of injured patients. Current methods of treatment are often imperfect and pose the risk of complications in the long term. Therefore, tissue engineering is a rapidly developing branch of science, which aims at discovering effective ways of replacing or repairing damaged tissues with the use of scaffolds. However, both cartilage and bone owe their exceptional mechanical properties to their complex ultrastructure, which is very diffcult to reproduce artificially. To address this issue, nanotechnology was employed. One of the most promising nanomaterials in this respect is carbon nanotubes, due to their exceptional physico-chemical properties, which are similar to collagens—the main component of the extracellular matrix of these tissues. This review covers the important aspects of 3D scaffold development and sums up the existing research tackling the challenges of scaffold design. Moreover, carbon nanotubes-reinforced bone and cartilage scaffolds manufactured using the 3D bioprinting technique will be discussed as a novel tool that could facilitate the achievement of more biomimetic structures.

Keywords:
tissue engineering, biomaterials, cartilage, bone, carbon nanotubes, scaffolds, bioprinting

Abstract:
New semiconducting metal oxides of various compositions are of great interest for efficient solar water oxidation. In this report, Mo-doped SnO2 (Mo:SnO2) thin films deposited by reactive magnetron co-sputtering in the Ar and O2 gas environment are studied. The Sn to Mo ratio in the films can be controlled by changing the O2 partial pressure and the deposition power of the Sn and Mo targets. Increasing the Mo concentration in the film leads to the increase in the oxygen vacancy density, which limits the maximum achievable photocurrent density. The thin films exhibit a direct band gap of 2.7 eV, the maximum achievable photocurrent density of 0.6 mA cm^−2 at 0 VRHE and the onset potential of 0.14 VRHE. The incident photon to current transfer (IPCE) efficiency of 22% is shown at a 450 nm wavelength. The initial performance of the Mo:SnO2 thin films is evaluated for solar water oxidation.

Keywords:
Mo:SnO2, thin films, photoanode, photocurrent density, Sn/mo ratio, band gap

Abstract:
Ultrasensitive sensors of various physical properties can be based on percolation systems, e.g., insulating media filled with nearly touching conducting particles. Such a system at its percolation threshold featuring the critical particle concentration, changes drastically its response (electrical conduction, light transmission, etc.) when subjected to an external stimulus. Due to the critical nature of this threshold, a given state at the threshold is typically very unstable. However, stability can be restored without significantly sacrificing the structure sensitivity by forming weak connections between the conducting particles. In this work, we employed nano-bridged nanosphere lithography to produce such a weakly connected percolation system. It consists of two coupled quasi-Babinet complementary arrays, one with weakly connected, and the other with disconnected metallic islands. We demonstrate via experiment and simulation that the physics of this plasmonic system is non-trivial, and leads to the extraordinary optical transmission at narrowly defined peaks sensitive to system parameters, with surface plasmons mediating this process. Thus, our system is a potential candidate for percolation effect based sensor applications. Promising detection schemes could be based on these effects.

Abstract:
Superparamagnetic iron oxide nanoparticles (SPIONs) have been investigated for wide variety of applications. Their unique properties render them highly applicable as MRI contrast agents, in magnetic hyperthermia or targeted drug delivery. SPIONs surface properties affect a whole array of parameters such as: solubility, toxicity, stability, biodistribution etc. Therefore, progress in the field of SPIONs surface functionalization is crucial for further development of therapeutic or diagnostic agents. In this study, SPIONs were synthesized by thermal decomposition of iron (III) acetylacetonate Fe(acac)3 and functionalized with dihexadecyl phosphate (DHP) via phase transfer. Bioactivity of the SPION-DHP was assessed on SW1353 and TCam-2 cancer derived cell lines. The following test were conducted: cytotoxicity and proliferation assay, reactive oxygen species (ROS) assay, SPIONs uptake (via Iron Staining and ICP-MS), expression analysis of the following genes: alkaline phosphatase (ALPL); ferritin light chain (FTL); serine/threonine protein phosphatase 2A (PP2A); protein tyrosine phosphatase non-receptor type 11 (PTPN11); transferrin receptor 1 (TFRC) via RT-qPCR. SPION-DHP nanoparticles were successfully obtained and did not reveal significant cytotoxicity in the range of tested concentrations. ROS generation was elevated, however not correlated with the concentrations. Gene expression profile was slightly altered only in SW1353 cells.

Abstract:
We study the large-amplitude response of classical molecules to electromagnetic radiation, showing the universality of the transition from linear to nonlinear response and breakup at sufficiently large amplitudes. We demonstrate that a range of models, from the simple harmonic oscillator to the successful Peyrard-Bishop-Dauxois type models of DNA, which include realistic effects of the environment (including damping and dephasing due to thermal fluctuations), lead to characteristic universal behavior: formation of domains of dissociation in driving force amplitude-frequency space, characterized by the presence of local boundary minima. We demonstrate that by simply following the progression of the resonance maxima in this space, while gradually increasing intensity of the radiation, one must necessarily arrive at one of these minima, i.e., a point where the ultrahigh spectral selectivity is retained. We show that this universal property, applicable to other oscillatory systems, is a consequence of the fact that these models belong to the fold catastrophe universality class of Thom's catastrophe theory. This in turn implies that for most biostructures, including DNA, high spectral sensitivity near the onset of the denaturation processes can be expected. Such spectrally selective molecular denaturation could find important applications in biology and medicine.

Abstract:
We develop nano-bridged nanosphere lithography (NB-NSL), a modification to the widely used conventional nanosphere lithography (NSL). Nano-bridges between polystyrene (PS) spheres of a pristine NSL template are controllably formed in a two-step process: (i) spin-coating of a dilute styrene solution on top of the template, followed by (ii) oxygen plasma etching of the template. We show that the nanobridge dimensions can be precisely tuned by controlling the pre-processing conditions and the plasma etching time. The resulting lithography templates feature control over the shape and size of the apertures, which determine the morphology of the final nano-island arrays after material deposition and template removal. The unique advantage of NB-NSL is that PS particle templates based on a single PS particle diameter can be utilized for the fabrication of a variation of nano-island shapes and sizes, whereas conventional NSL yields only bowtie-shaped nano-islands, with their size being predetermined by the PS particle diameter of the template.

Keywords:
nanofabrication, nanosphere lithography, colloid lithography

Abstract:
The Eu3+ and Sr2+ ions co-doped hydroxyapatite nanopowders (Ca10(PO4)6(OH)2) were synthesized via a precipitation method and post heat-treated at 500 °C. The concentration of Eu3+ ions was established in the range of 0.5–5 mol% to investigate the site occupancy preference. The concentration of Sr2+ ions was set at 5 mol%. The structural and morphological properties of the obtained materials were studied by an X-ray powder diffraction, a transmission electron microscopy techniques and infrared spectroscopy. As synthesized nanoparticles were in the range of 11–17 nm and annealed particles were in the range of 20–26 nm. The luminescence properties in dependence of the dopant concentration and applied temperature were investigated. The 5D0 → 7F0 transition shown the abnormally strong intensity for annealed materials connected with the increase of covalency character of Eu3+–O2− bond, which arise as an effect of charge compensation mechanism. The Eu3+ ions occupied three possible crystallographic sites in these materials revealed in emission spectra: one Ca(1) site with C3 symmetry and two Ca(2) sites with Cs symmetry arranged as cis and trans symmetry. The antibacterial properties of Eu3+ and Sr2+ ions doped and co-doped hydroxyapatite nanopowders were also determined against Gram-negative pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. Obtained results suggest that both europium and strontium ions may implement antibacterial properties for hydroxyapatites. In the most cases, better antibacterial effect we noticed for dopants at 5 mol% ratio. However, the effect is strongly species- and strain-dependent feature.

Keywords:
spectroscopy, apatite, biomaterial, europium, strontium, antibacterial activity

Abstract:
There is an urgent need for new materials that can catalyze or drive the photoelectrochemical (PEC) conversion of solar energy into chemical energy, i.e. solar fuels. Copper bismuth oxide (CBO) is a promising photocathode material for the photochemical reduction of water. Here, we systematically control the stoichiometry of CBO thin films prepared by reactive, direct-current magnetron co-sputtering from metallic Bi and Cu targets. The intrinsic photophysical and PEC material properties are investigated and evaluated in order to determine the optimum composition for hydrogen formation. Changing the stoichiometry of the films reveals a dramatic change in the optical band gap and crystal structure of CBO. The largest photocurrent density was achieved for a copper-to-bismuth ion ratio of 0.53, close to the CuBi2O4 stoichiometry, which yielded Jph = − 0.48 mA cm^−2 at 0 VRHE (RHE = reversible hydrogen electrode). This is the highest value to date for the photochemical reduction of water with CuBi2O4 without an externally applied bias. The absorbed photon-to-current efficiency and the photostability of the films in neutral and alkaline electrolytes were also investigated.

Keywords:
CuBi2O4, copper bismuth oxide, water reduction, water splitting, photocathode, magnetron sputtering

Abstract:
Bioengineered spider silk is a biomaterial that has exquisite mechanical properties, biocompatibility, and biodegradability. Iron oxide nanoparticles can be applied for the detection and analysis of biomolecules, target drug delivery, as MRI contrast agents and as therapeutic agents for hyperthermia-based cancer treatments. In this study, we investigated three bioengineered silks, MS1, MS2 and EMS2, and their potential to form a composite material with magnetic iron oxide nanoparticles (IONPs). The presence of IONPs did not impede the self-assembly properties of MS1, MS2, and EMS2 silks, and spheres formed. The EMS2 spheres had the highest content of IONPs, and the presence of magnetite IONPs in these carriers was confirmed by several methods such as SEM, EDXS, SQUID, MIP-OES and zeta potential measurement. The interaction of EMS2 and IONPs did not modify the superparamagnetic properties of the IONPs, but it influenced the secondary structure of the spheres. The composite particles exhibited a more than two-fold higher loading efficiency for doxorubicin than the plain EMS2 spheres. For both the EMS2 and EMS2/IONP spheres, the drug revealed a pH-dependent release profile with advantageous kinetics for carriers made of the composite material. The composite spheres can be potentially applied for a combined cancer treatment via hyperthermia and drug delivery.

Abstract:
Core-virus like particles (VLPs) assembly is a kinetically complex cascade of interactions between viral proteins, nanoparticle's surface and an ionic environment. Despite many in silico simulations regarding this process, there is still a lack of experimental data. The main goal of this study was to investigate the capsid protein of hepatitis B virus (HBc) assembly into virus-like particles with superparamagnetic iron oxide nanoparticles (SPIONs) as a magnetic core in relation to their characteristics. The native form of HBc was obtained via agroinfection of Nicotiana benthamiana with pEAQ-HBc plasmid. SPIONs of diameter of 15 nm were synthesized and functionalized with two ligands, providing variety in ζ-potential and hydrodynamic diameter. The antigenic potential of the assembled core-VLPs was assessed with enzyme-linked immunosorbent assay (ELISA). Morphology of SPIONs and core-VLPs was evaluated via transmission electron microscopy (TEM). The most successful core-VLPs assembly was obtained for SPIONs functionalized with dihexadecyl phosphate (DHP) at SPIONs/HBc ratio of 0.2/0.05 mg/mL. ELISA results indicate significant decrease of antigenicity concomitant with core-VLPs assembly. In summary, this study provides an experimental assessment of the crucial parameters guiding SPION-HBc VLPs assembly and evaluates the antigenicity of the obtained structures.

Keywords:
virus-like particles, VLPs, hepatitis B virus capsid protein, HBc, viral self-assembly, magnetic core, HBcAg

Abstract:
A plasmonic structure with transmission highly tunable in the mid-infrared spectra range is developed. This structure consists of a hexagonal array of metallic discs located on top of silicon pillars protruding through holes in a metallic Babinet complementary film. We reveal with FDTD simulations that changing the hole diameter tunes the main plasmonic resonance frequency of this structure throughout the infrared range. Due to the underlying Babinet physics of these coupled arrays, the spectral width of these plasmonic resonances is strongly reduced, and the higher harmonics are suppressed. Furthermore, we demonstrate that this structure can be easily produced by a combination of the nanosphere lithography and the metal-assisted chemical etching technique.

Abstract:
Long-term space flights and cis-lunar research platforms require a sustainable and light life-support hardware which can be reliably employed outside the Earth's atmosphere. So-called 'solar fuel' devices, currently developed for terrestrial applications in the quest for realizing a sustainable energy economy on Earth, provide promising alternative systems to existing air-revitalization units employed on the International Space Station (ISS) through photoelectrochemical water-splitting and hydrogen production. One obstacle for water (photo-) electrolysis in reduced gravity environments is the absence of buoyancy and the consequential, hindered gas bubble release from the electrode surface. This causes the formation of gas bubble froth layers in proximity to the electrode surface, leading to an increase in ohmic resistance and cell-efficiency loss due to reduced mass transfer of substrates and products to and from the electrode. Recently, we have demonstrated efficient solar hydrogen production in microgravity environment, using an integrated semiconductor-electrocatalyst system with p-type indium phosphide as the light-absorber and a rhodium electrocatalyst. By nanostructuring the electrocatalyst using shadow nanosphere lithography and thereby creating catalytic 'hot spots' on the photoelectrode surface, we could overcome gas bubble coalescence and mass transfer limitations and demonstrated efficient hydrogen production at high current densities in reduced gravitation. Here, the experimental details are described for the preparations of these nanostructured devices and further on, the procedure for their testing in microgravity environment, realized at the Bremen Drop Tower during 9.3 s of free fall.

Keywords:
chemistry, issue 154, solar fuels, hydrogen, microgravity, photoelectrocatalysis, drop tower, shadow nanosphere lithography, semiconductor-electrocatalyst systems

Abstract:
Colloidal silver sols of long-time stability are formed in the γ-irradiation of 1.0 x 10^-4 M AgClO4 solutions, which also contain 0.3 M 2-propanol, 2.5 x 10^-2 M N2O, and sodium citrate in various concentrations. The reduction of Ag+ in these solutions is brought about by the 1-hydroxyalkyl radical generated in the radiolysis of 2-propanol; citrate does not act as a reductant but solely as a stabilizer of the colloidal particles formed. Its concentration is varied in the range from 5.0 x 10^-5 to 1.5 x 10^-3 M, and the size and size distribution of the silver particles are studied by electron microscopy. At low citrate concentration, partly agglomerated large particles are formed that have many imperfections. In an intermediate range (a few 10^-4 M), wellseparated particles with a rather narrow size distribution and little imperfections are formed, the size slightly decreasing with increasing citrate concentration. At high citrate concentrations, large lumps of coalesced silver particles are present, due to destabilization by the high ionic strength of the solution. These findings are explained by two growth mechanisms: condensation of small silver clusters (type-I growth), and reduction of Ag+ on silver particles via radical-to-particle electron transfer (type-II growth). The particles formed in the intermediate range of citrate concentration were studied by high-resolution electron microscopy and computer simulations. They constitute icosahedra and cuboctahedra.

Abstract:
Gold colloids have been homogeneously coated with silica using the silane coupling agent (3-aminopropyl)- trimethoxysilane as a primer to render the gold surface vitreophilic. After the formation of a thin silica layer in aqueous solution, the particles can be transferred into ethanol for further growth using the Stöber method. The thickness of the silica layer can be completely controlled, and (after surface modification) the particles can be transferred into practically any solvent. Varying the silica shell thickness and the refractive index of the solvent allows control over the optical properties of the dispersions. The optical spectra of the coated particles are in good agreement with calculations using Mie's theory for core-shell particles.

Abstract:
Improved synthetic routes and size-selective precipitation have enabled the preparation of almost monodisperse CdS clusters. Six samples of 1-thioglycerol stabilized clusters with diameters of approximately 13,14,16,19, 23, and 39 A have been prepared as fully redispersible powders and were characterized by elemental analysis, powder X-ray diffraction, electron microscopy, thermogravimetric analysis, and UV-vis spectroscopy. Smallangle X-ray scattering was used to determine the mean cluster size. The well-structured UV-vis spectra reveal that the size-dependent shift of the 1s-1s excitonic transition is in agreement with the tight-binding theory and the pseudopotential theory. Moreover, as expected by quantum mechanical calculations the oscillator strength of the transition increases proportional to 1/r^3. UV-vis spectra taken at various temperatures between 4 and 295 K have shown that the temperature shift of the excitonic transition energy becomes stronger with decreasing particle size. Strong, reversible absorbance shifts were observed, upon transferring the clusters from their solutions onto quartz plates and vice versa.

Abstract:
Citrate- and alkanethiol-stabilized gold colloids have been electrophoretically deposited onto carboncoated copper grids. The colloid particles form ordered monolayers, and the core-to-core interparticle spacing is determined by the size of the alkane chains on the stabilizers used in the preparation of the sols. In the case of longer alkane chains, some interpenetration of the chains occurs when the gold particles form monolayers. When the gold sols are stabilized by sodium 3-thiopropionate, they can be reversibly coagulated and peptized by cycling the pH between 3 and 7. The method has also been used to form ordered monolayers and bilayers of latex particles.

Abstract:
Environmental pollution caused by anthropogenic activities is one of the biggest challenges globally.
One of the largest groups of compounds polluting the aquatic environment are antibiotics, dyes, and pigments, which are mainly released from manufacturing waste from textile, wood, and pharmaceutical industries. Such chemicals not only affect animals living in aquatic systems, but also cause a range of health problems in humans, increasing the risk of cancer and disrupting the endocrine and immune systems. In this work, we focus on wastewater treatment solutions based on magnetic nanomaterials that can effectively purify water through adsorption and can also act as a photocatalyst that can degrade pollutants. The proposed nanomaterials and their composites offer non-toxicity, high surface area and magnetic properties that can be easily removed from solution after wastewater treatment with magnets. The proposed nanomaterials, in particular superparamagnetic iron oxide nanoparticles (SPIONs) and their composites with spent biomass and pyrolyzed biomass, offer high efficiency in water treatment, rapid separation from treated solutions and reuse. Furthermore, SPIONs can also be combined with a wide variety of metal ions, making them a promising platform for the removal of heavy metal ions from contaminated solutions, such as hydrometallurgical waste. The work will discuss the synthesis and characterization as well as the model of adsorption and mechanism of pollutants removal.

Abstract:
Over the past 20 years, there has been a dramatic increase in the incidence of various cancers. The increased detection of various malignancies and their effective treatment requires the search for new approaches in anti-cancer therapy. One option is the use of nanomaterials and nanocomposites based on them to form a platform for simultaneous imaging, such as by nuclear magnetic resonance, and treatment by local drug release and temperature elevation directly in tumor tissues [1]. Here, we present results on the colloidal suspension based on superparamagnetic iron-oxide-based nanoparticles and hydroxyapatites as the matrix for the local anticancer drug release. The studies were focused on the optimization of the synthesis experimental composition, characterization of obtained material, and stability in aqueous solutions like PBS to be used in magnetic hyperthermia to generate heat locally and enhance the drug delivery. Core-shell particles were synthesized using a two-step wet co-precipitation method and stabilized with biocompatible organic molecules to produce stable colloidal suspension [2,3]. The heat generation effectiveness was determined using magnetic hyperthermia (MH), where the conditions to reach therapeutic temperature of the suspension in the constant and pulsed amplitude of alternating magnetic field (AMF) were optimized.