Ion Beam Defect Engineering on ReS2/Si Photocathode with Significantly Enhanced Hydrogen Evolution Reaction

Loading 2D layered transition metal dichalcogenides (TMDs) on p-type silicon photocathode is suitable for hydrogen production in solar-driven photoelectrochemical (PEC) water splitting. Similarly, various nanostructured TMDs exposing more active sites are widely explored for improving the PEC performances of composite photoelectrodes. Here, defect engineering using a controllable argon ion beam bombardment is presented on ReS 2 /Si photocathode. The atomic vacancy defects are introduced on the 2D ReS 2 to realize high-density active sites, which significantly enhance the solar-driven hydrogen evolution reaction performance of ReS 2 /Si photocathode. The highest photocurrent density of 18.5 mA cm −2 (at 0 V vs reversible hydrogen electrode) is achieved, under a simulated sun irradiation.