Local photocatalytic H2 generation on individual microscale two-dimensional CdSe nanosheets

Abstract Synthesis of two-dimensional (2D) CdSe with microscale lateral dimensions is a challenge in colloidal chemistry. Herein, micrometer-sized CdSe nanosheets (NSs) have been successfully synthesized through a versatile cation exchange approach using microscale Cu 2-x Se NSs as a template. By replacing Cu + ion with Cd 2+ ion within the NSs template, CdSe NSs with lateral dimensions up to 6 μm, beyond which can be synthesized directly by colloidal chemistry, have been obtained. Notably, resulting CdSe NSs retain the 2D morphology with well-defined shape and size. We then demonstrate the use of large CdSe NSs in the application of local photocatalytic H 2 generation. The H 2 gas bubble evolution on the individual NSs was successfully detected and the local rate was determined.