Composition Control of Two-Dimensional Cu_2-xS/CdS Heterostructured Nanoplates via Cation Exchange Reaction for Photocatalytic Hydrogen Generation under Visible Light

Solar-to-fuel conversion using semiconductor materials has long been studied as a promising sustainable and clean energy solution. Among various reactions, photocatalytic hydrogen generation holds significant potential for the development of clean and renewable energy sources. To enhance the efficiency of photocatalytic activity, heterostructures has been explored to reduce electron-hole recombination and promote increased charge separation efficiency. In this study, we present the controlled metal ratio of two-dimensional Cu_2-xS/CdS heterostructured nanoplate achieved through a cation exchange reaction. By adjusting the composition ratio, we investigated the photocatalytic activity and focused on the optical and photochemical properties. Notably, a 65% of Cd content of Cu_2-xS/CdS heterostructured nanoplate exhibited the highest photocatalytic activity, surpassing that of a similar one-dimensional Cu_2-xS/CdS system. Our observation provides a guideline to the rational design of semiconductor-semiconductor heterojunctions in two-dimensional nanostructures for enhanced photocatalytic activity.