Ag/AgVO <sub>3</sub> /g-C <sub>3</sub> N <sub>4</sub> Ternary Nanocomposites for Enhanced Photo- and Electrocatalytic Hydrogen Evolution: Synergistic Charge Separation and Interfacial Engineering
Kotesh Kumar Mandari, Rajasheker Reddy Eragari, Misook Kang
Abstract
Nanocomposite catalysts are advantageous for photo/electrocatalysis due to their exceptional stability, charge transfer efficiency, and interfacial interactions. Conventional semiconductor photocatalysts, such as g-C 3 N 4, face challenges like high charge recombination rates and insufficient catalytic sites. To address these issues, silver (Ag) nanoparticles and AgVO 3 nanowires were integrated onto the g-C 3 N 4 surface to synthesize Ag/AgVO 3 /g-C 3 N 4 nanocomposites for water splitting. XRD and XPS analyses confirm the successful integration of silver vanadate onto the g-C 3 N 4 matrix, revealing the presence of Ag/AgVO 3 and g-C 3 N 4 . The morphology demonstrates the crystalline nature and strong interfacial connections between g-C 3 N 4 and Ag/AgVO 3, suggesting enhanced photocatalytic performance. Compared to individual Ag/AgVO 3 and g-C 3 N 4 components, the Ag/AgVO 3 /g-C 3 N 4 catalyst exhibits significantly higher photo/electrocatalytic H 2 production rates. The highest photocatalytic H 2 yield of 3602 μmol·g –1 was produced with the 15% Ag/AgVO 3 /g-C 3 N 4 heterostructure, surpassing the yields of Ag/AgVO 3 and g-C 3 N 4 by 8.7 and 22.3 times, respectively. Additionally, the 15% Ag/AgVO 3 /g-C 3 N 4 catalyst demonstrates improved reaction kinetics in the hydrogen evolution reaction with a lower overpotential of 112 mV and a Tafel slope of 63 mV/dec in 1 M KOH. The exceptional photo/electrocatalytic performance of the 15% Ag/AgVO 3 /g-C 3 N 4 nanocomposite is attributed to efficient charge separation and optimal interfacial interactions among Ag, AgVO 3, and g-C 3 N 4, facilitating electron transport and reducing charge recombination. This study proposes a highly efficient g-C 3 N 4 -based catalyst design with significant potential for energy conversion applications in photo- and electrocatalysis.