Surfactant-assisted hydrothermal synthesis of silver tungstate with controlled phase composition and morphology for enhanced electrochemical hydrogen storage

Abstract

In this study, Ag₂WO₄ structures were synthesized via a hydrothermal method using four different surfactants: polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and sodium dodecylbenzene sulfonate (SDBS). The effects of surfactant type on the phase purity, morphology, particle size, and electrochemical hydrogen storage capacity of the synthesized samples were systematically investigated. The structural analyses confirmed that the use of different surfactants led to distinct morphologies and variations in phase composition, ranging from pure to mixed phases. Electrochemical measurements after 15 charge–discharge cycles in alkaline electrolyte demonstrated that the sample prepared with polyvinylpyrrolidone (PVP) exhibited the highest hydrogen storage capacity, reaching approximately 1200 mAh g^− 1. The findings indicate that the choice of surfactant during synthesis significantly influences the structural and electrochemical properties of Ag₂WO₄, suggesting its potential as a promising material for hydrogen storage applications.