Synergistic Plasmonic-Catalytic Engineering of AgCo/g-C3N4 Nanocomposites for Efficient Photocatalytic and Electrocatalytic Hydrogen Evolution

Abstract

This study presents the synthesis of a bimetallic AgCo/g-C₃N₄ nanocomposite through an efficient surfactant-assisted deposition co-reduction technique and evaluates its bifunctional potential in both photocatalytic and electrocatalytic water splitting. The structural and spectroscopic characterizations reveal the uniform dispersion of AgCo bimetallic nanoparticles on the g-C₃N₄ matrix, which enhances the photoresponse qualities, promotes charge separation and extends its lifespan through synergistic effects. Surprisingly, the incorporation of g-C₃N₄ notably improved the photocatalytic efficiency of the nanocomposite compared to the individual AgCo or g-C₃N₄ catalysts owing to the effective interfacial interaction between the counterparts of the nanocomposite. AgCo(3:1)/g-C₃N₄ exhibits a remarkable photocatalytic H₂ evolution rate of 16,573.9 µmol g⁻¹ h⁻¹ under visible-light irradiation, outperforming both pristine g-C₃N₄ and AgCo(3:1). For electrocatalytic H₂ evolution, the nanocomposite exhibits an overpotential of 373.27 mV at 10 mA cm⁻² and a favorable Tafel slope of 94.6 mV dec⁻¹, surpassing the activities of individual components of the nanocomposite. The synergistic plasmonic and catalytic role of Ag and Co along with the unique electronic properties of g-C₃N₄ leads to the enhancement in catalytic performances. Further, the stability assessments exhibit persistent catalytic activity over multiple cycles with negligible efficiency loss.