Interfacial Engineering of V2O5 via Conductive Polyaniline for Accelerated Hydrogen Evolution Reaction

The hydrogen evolution reaction (HER) plays a pivotal role in electrochemical water splitting for sustainable hydrogen production. However, its practical implementation is hindered by sluggish kinetics and the reliance on costly noble-metal catalysts. In this work, a conductive polymer-inorganic hybrid electrode based on vanadium pentoxide (V2O5) and polyaniline (PANI) is rationally designed and fabricated on carbon cloth via a combined hydrothermal synthesis and electropolymerization strategy. Initially, hierarchical V2O5 nanoflowers were synthesized, followed by controlled PANI deposition through cyclic voltammetry at varying cycle numbers to tailor the interfacial architecture and electronic properties. Morphological and structural analyses reveal the formation of well-defined V2O5 nanoflowers uniformly decorated with PANI nanorods, establishing an interconnected conductive network. Among the prepared samples, the optimized V2O5-PANI-2 electrode exhibits superior interfacial integration and structural homogeneity. Electrochemical evaluation in 1.0 M KOH demonstrates that V2O5-PANI-2 achieves a low overpotential of 79.9 mV at −10 mA cm−2, accompanied by a small Tafel slope of 46.6 mV dec−1, indicating accelerated HER kinetics. Furthermore, the electrode shows reduced charge-transfer resistance and an enhanced electrochemically active surface area (ECSA), facilitating efficient charge transport and abundant active site exposure. The catalyst also delivers excellent durability, maintaining stable performance over 5000 CV cycles and prolonged 24 h operation. The enhanced HER performance is attributed to the synergistic interaction between V2O5 and the conductive PANI matrix, which promotes charge redistribution, improves electrical conductivity, and optimizes the adsorption/desorption energetics of hydrogen intermediates.