Mrunal Bhosale

Developing multifunctional electrodes for simultaneous energy storage and conversion is essential for sustainable energy technologies. Herein, we report Cu ₂ O coating on niobium phosphate creates a heterogeneous interface that promotes charge separation, reduces interfacial resistance, and stabilizes redox‐active Cu sites. Niobium phosphate acts as a chemically robust, ion‐friendly scaffold, while the Cu ₂ O couple provides a dynamically active surface accelerating electron transfer and intermediate adsorption. The intimate NbP@Cu ₂ O heterointerface induces interfacial charge redistribution and strong electronic coupling, enabling rapid charge transfer, accelerated ion diffusion, and enhanced electrochemical kinetics for improved reaction performance. Consequently, the NbP@Cu ₂ O electrode delivers a high specific capacity of 23.40 F/cm ² at 5 mA/cm ² , approximately 2.4 times higher than pristine NbP, together with excellent rate capability and coulombic efficiency. The assembled device achieves a specific capacitance of 410 mF/cm ² , an energy density of 128 μWh/cm ² at a power density of 760 μW/cm ² and demonstrated robust endurance over an extended 100000‐cycle test (65% retention; 0.00035% loss per cycle). Furthermore, the heterostructure exhibits outstanding OER activity with a low overpotential of 275.2 mV at 100 mA/cm ² , a Tafel slope of 48.2 mV/dec, and stable operation for 120 h. These findings demonstrate the potential of phosphate‐oxide heterointerface engineering for advanced bifunctional energy storage and conversion applications. image

Oxygen evolution reaction (OER) remains the primary kinetic bottleneck in alkaline water electrolysis, necessitating the development of efficient, economically viable, and earth-abundant electrocatalysts. Herein, a facile sodium dodecyl sulfate (SDS)-assisted hydrothermal strategy is employed to synthesize nanostructured NiMoO₄ electrocatalysts with tailored morphology and enhanced electrocatalytic activity. Acting as a soft-template and structure-directing agent, SDS regulates the nucleation and growth of NiMoO₄, resulting in a porous and interconnected nanostructure with abundant exposed active sites. The optimized NiMoO₄-SDS-2 electrode exhibits outstanding OER performance, requiring an overpotential of only 428.5 mV to achieve a current density of 100 mA cm⁻², together with a Tafel slope of 62.4 mV dec⁻¹, demonstrating accelerated reaction kinetics. Electrochemical impedance spectroscopy and double-layer capacitance analyses reveal enhanced charge-transfer capability and a larger electrochemically active surface area, while long-term durability tests confirm excellent operational stability under alkaline conditions. The enhanced catalytic performance is associated with SDS-induced morphology regulation, improved active-site accessibility, and favorable interfacial charge-transfer characteristics. This work demonstrates that surfactant-assisted soft-templating is an effective strategy for engineering high-performance NiMoO₄-based electrocatalysts and provides valuable insights into the rational design of advanced transition metal oxide catalysts for efficient and durable alkaline water oxidation.

In hydrogen production technologies, the greener way of electrocatalytic water splitting techniques has gained considerable attention because of the utilization of renewable energy as a source to produce hydrogen without any harmful emissions.

The rational design of cost-effective and highly active electrocatalysts for overall water splitting remains a critical challenge for sustainable hydrogen production. Herein, we report a two-dimensional reduced graphene oxide (rGO)-supported Mo₂S₃ nanohybrid catalyst with a tunable electronic structure engineered through interfacial coupling. The intimate integration of Mo₂S₃ nanoflakes with conductive rGO nanosheet facilitates rapid electron transport, enhanced active site exposure, and optimized adsorption energetics for reaction intermediates. Structural and spectroscopic analyses confirm strong electronic interaction between Mo₂S₃ and rGO, leading to modulated charge density distribution and improved intrinsic catalytic activity. Electrochemical evaluations reveal significantly reduced overpotentials for oxygen evolution reaction (OER) with 166 mV overpotential at 10 mA cm⁻² current density, along with favorable Tafel kinetics with 38.1 mV dec⁻¹ and long-term operational stability in alkaline electrolyte. The rGO-Mo₂S₃-2||Pt-C cell delivers 10 mA cm⁻² at 1.64 V, indicating efficient alkaline water splitting. The enhanced performance is attributed to synergistic effects arising from electronic modulation, enhanced active sites, and accelerated interfacial charge transfer.

Developing effectual, stable, and earth-abundant electrocatalysts for the oxygen evolution reaction (OER) remains pivotal for advancing sustainable hydrogen production via electrochemical water splitting. Herein, we report the rational design of Co₃O₄ nanowire arrays hierarchically decorated with α-MoO₃ nanoflowers (Co₃O₄@α-MoO₃) grown directly on nickel foam via a scalable hydrothermal strategy. By optimizing MoO₃ loading, the Co₃O₄@α-MoO₃-2 heterostructure achieves an ultralow overpotential of 209 mV at 10 mA cm⁻², a Tafel slope of 60 mV dec⁻¹, and superior charge-transfer kinetics in 1 M KOH. Comprehensive analysis reveals that the synergistic interfacial coupling enhances electronic conductivity, exposes abundant active sites (ECSA = 1106.50 cm²), and optimizes OER intermediate adsorption through mixed valence Co/Mo centers and oxygen defects. This work elucidates morphology–composition synergy in oxide heterostructures, offering a blueprint for high-performance OER electrocatalysts.

Precise control over nanostructure evolution is critical for optimizing the electrochemical performance of pseudocapacitive materials. In this work, Nb₂O₅ nanostructures were synthesized via a time-engineered hydrothermal route by systematically varying the reaction duration (6, 12, and 18 h) to elucidate its influence on structural development, charge storage kinetics, and supercapacitor performance. Structural and surface analyses confirm the formation of phase-pure monoclinic Nb₂O₅ with a stable Nb⁵⁺ oxidation state. Morphological investigations reveal that a 12 h reaction time produces hierarchically organized Nb₂O₅ architectures composed of nanograin-assembled spherical aggregates with interconnected porosity, providing optimized ion diffusion pathways and enhanced electroactive surface exposure. Electrochemical evaluation demonstrates that the NbO-12 electrode delivers superior pseudocapacitive behavior dominated by diffusion-controlled Nb⁵⁺/Nb⁴⁺ redox reactions, exhibiting high areal capacitance (5.504 F cm⁻² at 8 mA cm⁻²), fast ion diffusion kinetics, low internal resistance, and excellent cycling stability with 85.73% capacitance retention over 12,000 cycles. Furthermore, an asymmetric pouch-type supercapacitor assembled using NbO-12 as the positive electrode and activated carbon as the negative electrode operates stably over a wide voltage window of 1.5 V, delivering an energy density of 0.101 mWh cm⁻² with outstanding durability. This study establishes hydrothermal reaction-time engineering as an effective strategy for tailoring Nb₂O₅ nanostructures and provides valuable insights for the rational design of high-performance pseudocapacitive electrodes for advanced energy storage systems.

The electrochemical water splitting process represents a promising and sustainable route for generating high-purity hydrogen with minimal environmental impact. The development of efficient and economically viable electrocatalysts is crucial for enhancing the kinetics of the oxygen evolution reaction (OER), which is a major bottleneck in overall water splitting. In this study, a Co₃V₂O₈/PEG-CTAB electrocatalyst was synthesized and systematically evaluated for its OER activity in alkaline conditions. The nanosheet-like architecture of the PEG-CTAB-assisted Co₃V₂O₈ electrocatalyst facilitates effective interfacial contact, thereby improving charge transport and catalytic accessibility. Among the examined compositions, the Co₃V₂O₈/PEG-CTAB catalyst exhibited superior OER performance, requiring a low overpotential of 298 mV to deliver a current density of 10 mA cm⁻² and displaying a Tafel slope of 90 mV dec⁻¹ in 1 M KOH. Furthermore, the catalyst demonstrated outstanding durability, retaining its electrocatalytic activity after 5000 consecutive CV cycles and prolonged chronopotentiometric testing. The Co₃V₂O₈/PEG-CTAB || Pt-C asymmetric cell required a cell voltage of 1.83 V to reach the threshold current density, confirming its ability to efficiently sustain overall water splitting under alkaline conditions. The enhanced performance is attributed to the synergistic effect of the electrocatalyst, which promotes active site exposure and structural stability. These findings highlight the potential of the Co₃V₂O₈/PEG-CTAB system as a cost-effective and robust electrocatalyst for practical water oxidation applications.