Staff

Abstract:
A gadolinium hydroxide–MXene nanocomposite was synthesized through a microwave-assisted route as a supercapacitor electrode material. The prepared electrode material demonstrated a specific capacity of 128 mAh g−1, along with 98% capacitance retention after 5000 cycles. An solid-state hybrid supercapacitor (Gd–MX//AC) delivered an energy density of 25.8 Wh kg−1 and a high power density of 3000 W kg−1, while maintaining outstanding capacitance retention over repeated cycles.

Abstract:
Nickel–iron-layered double hydroxides (NiFe-LDH) are known for their strong electrochemical activity and low cost, yet their practical use in energy-storage devices is restricted by limited electrical conductivity and sluggish ion transport. To address these limitations, conductive additives are commonly incorporated into hydroxide frameworks to enhance charge mobility and overall electrochemical response. In this study, a binder-free NiFe-LDH/Ti3C2Tₓ MXene nanocomposite was fabricated through a hydrothermal synthesis route and then applied as a supercapacitor electrode. Material characterization results confirmed the successful formation of NiFe-LDH with uniformly dispersed MXene sheets, yielding a nanoflower-like hierarchical structure. Such architecture increased the accessible surface area and generated a highly porous network, both of which promoted efficient electrochemical reactions. Electrochemical evaluation of the prepared electrode revealed a specific capacitance of 1512 F g−1 at 0.75 A g−1, along with strong rate performance. Furthermore, the assembled asymmetric supercapacitor delivered an energy density of 47.25 Wh kg−1 and a power density of 700 W kg−1, while retaining 65% of its capacitance after 10,000 charge–discharge cycles. The performance was improved compared to previous work on NiFe LDH due to strong interfacial coupling between LDH nanosheets and functionalized MXene surfaces.

Abstract:
Conducting polymers are widely explored as supercapacitor electrodes due to their reversible redox activity, electrical conductivity, and mechanical flexibility; however, their long-term cycling stability is often limited by structural degradation caused by repeated ion doping and dedoping. In this study, PPy–WS2 nanocomposites with systematically varied WS2 loadings were synthesized through an in-situ oxidative polymerization approach to elucidate how WS2 content influences morphology, surface chemistry, charge-transfer behaviour, and overall electrochemical performance. Unlike conventional reports that primarily highlight performance metrics of PPy-based hybrids, this work establishes a clear composition–structure–performance relationship and identifies the optimal WS2 fraction required to balance pseudocapacitive activity with mechanical and structural stability. Physicochemical characterization confirmed the successful integration of WS2 within the PPy matrix, forming an interconnected architecture that enhances electroactive-site accessibility and facilitates efficient ion and electron transport. Among the prepared materials, the PPy–20W electrode delivered the highest specific capacitance of 911 F g−1 at 1 mV s−1, along with excellent cycling durability. The improved performance arises from synergistic PPy redox activity, WS2-mediated interfacial charge storage, and enhanced charge-transfer kinetics. An asymmetric supercapacitor assembled using the optimized composite achieved an energy density of 32.5 Wh kg−1 and a power density of 1400 W kg−1, demonstrating the effectiveness of controlled WS2 incorporation for advancing PPy-based supercapacitor electrodes.

Keywords:
Polypyrrole, WS2, Dichalcogenide, Supercapacitor

Abstract:
The accelerated growth of industries in modern society has triggered the release of toxic dyes into the environment, presenting a serious ecological risk and posing challenges for effective removal. The mixed-metal-based photodegradation of methyl orange dye (MOD) in aqueous medium is elucidated by degradation byproducts. This study reveals the synergistic effect of Bi2SrO4(BSO), g-C3N4 (g-CN) and graphene oxide (GO) in enhancing the photocatalytic performance of BSO photocatalyst. XRD analysis was performed to identify the crystalline phase of the nanocomposite, while the morphology of the BSO/g-CN/GO was examined by SEM analysis. UV analysis reveals the incorporation of the g-CN and GO in BSO, significantly enhancing the visible-light-absorption which is well-suited for efficient photodegradation. BSO/g-CN/GO displays markedly superior photocatalytic activity relative to BSO, g-CN and BSO/g-CN owing to its decreased band gap value. The photodegradation activity of the prepared composite is evaluated via degrading MOD under stimulated to visible light conditions. The nanocomposite BSO/g-CN/GO demonstrates the phenomenal performance (93.5%) in the degradation of the MOD compared to the pristine materials. This significant improvement in performance is due to the formation of the S-scheme heterojunction. In essence, this study delivers new insights into the photocatalytic performance of the BSO/g-CN/GO underscoring its potential as a proficient photocatalyst for resolving environmental concerns.

Keywords:
Photocatalysis, Bi2SrO4, g-C3N4, Graphene Oxide, S-scheme, Methyl Orange

Abstract:
The rising demand for durable, high-power energy storage devices has driven the advancement of innovative electrode materials for modern supercapacitors. In this regard, microwave-assisted synthesis has emerged as a fast and energy-saving approach for producing nanocomposites with superior electrochemical features. In this work, Ce(OH)3-x wt%rGO (x = 5, 10, and 15) nanocomposites were prepared through a simple microwave-assisted route to enhance electrochemical efficiency in supercapacitor systems. Structural and morphological characterizations using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analysis confirm the effective incorporation of Ce(OH)3 with reduced graphene oxide (rGO) sheets, resulting in improved crystallinity, abundant defect sites, and larger surface area. Electrochemical testing in a three-electrode setup shows that the optimized CeG-10 electrode delivers a specific capacitance of 1229 F/g at 1 A/g, with strong rate capability and minimal internal resistance. Long-term cycling experiments demonstrate 92% capacitance retention after 10000 charge–discharge cycles, confirming excellent structural and electrochemical durability. Moreover, the fabricated supercapacitor device achieves an energy density of 49.46 Wh/kg at a power density of 1400 W/kg. These findings emphasize the promising potential of microwave-assisted Ce(OH)3-rGO nanocomposites as efficient electrode materials for next-generation energy storage technologies.

Keywords:
Supercapacitor, transition metal oxides, asymmetric supercapacitor, hydrothermal