Nano-twinned Ag Thin Films on Graphene/ Si Photoelectrochemical Cell for CO₂ Reduction and Hydrogen Production

Abstract

This study proposes a novel approach for applying the nanotwinned Ag thin films in CO2 reduction. We focus on optimizing the sputter deposition process of nanocrystalline Ag structures on n+Si chips and preparing nanotwinned silver catalysts with good structure, adhesion, and stability. The effects of twinned structure catalysts on the photocatalytic performance were investigated. In this research, the n+Si/Gr/sputtered Ag structure was used as the photoelectrode for photoelectrochemical (PEC) CO2 reduction reaction (CO2RR) since the utilization of graphene can expedite carrier transport, thereby improving device stability and performance in electrolytes. Nanotwinned Ag films were successfully synthesized on graphene transferred n+Si substrates with DC magnetron sputtering. Focused ion beam analyses demonstrated that the addition of graphene did not diminish the nanotwin density; rather, it improved the quality of the sputtered Ag thin films, which leads the framework to a potential structure for PEC CO2RR.