Synergistic Plasmonic‐Catalytic Engineering of AgCo/g‐C 3 N 4 Nanocomposites for Efficient Photocatalytic and Electrocatalytic Hydrogen Evolution

ABSTRACT This study presents the synthesis of a bimetallic AgCo/g‐C 3 N 4 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‐C 3 N 4 matrix, which enhances the photoresponse qualities, promotes charge separation and extends its lifespan through synergistic effects. Surprisingly, the incorporation of g‐C 3 N 4 notably improved the photocatalytic efficiency of the nanocomposite compared to the individual AgCo or g‐C 3 N 4 catalysts owing to the effective interfacial interaction between the counterparts of the nanocomposite. AgCo(3:1)/g‐C 3 N 4 exhibits a remarkable photocatalytic H 2 evolution rate of 16,573.9 µmol g −1 h −1 under visible‐light irradiation, outperforming both pristine g‐C 3 N 4 and AgCo(3:1). For electrocatalytic H 2 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‐C 3 N 4 leads to the enhancement in catalytic performances. Further, the stability assessments exhibit persistent catalytic activity over multiple cycles with negligible efficiency loss.