Spatially Separated Photoinduced Charge Carriers for the Enhanced Photocatalysis Over the One-Dimensional Yolk–Shell In2Se3@N-C Nanoreactor

Abstract

Charge separation is crucial for applications of semiconductors in photocatalysis, especially in the field of photocatalytic organic transformation involving both the electrons and holes. Herein, we have spatially separated the photoinduced charge carriers on a nanoscale by engineering both the composition and morphology of a semiconductor-based photocatalyst. A yolk–shell nanorod structure (In2Se3@N-C YSR), which is composed of interpenetrated In2Se3 nanosheets as the core and an N-doped carbon layer as the shell, has been fabricated. This yolk–shell structure with confined cavities can provide a high surface area and multiple light reflections. The spatial distribution of the In2Se3 nanosheets and N-doped carbon layer can provide spatially separated redox-active sites, due to the existence of a controlled transfer pathway from In2Se3 to N-doped carbon layer for electrons, which can be revealed by photocurrent measurements, time-resolved photoluminescence spectra, and density functional theory (DFT) calculations. Therefore, on the basis of the above merits, the obtained In2Se3@N-C YSR has exhibited highly enhanced photocatalytic activity toward photocatalytic organic transformations, including the selective oxidation of amines to imines and the cross-dehydrogenative coupling reaction. In addition, DFT calculations have also indicated that the effective adsorption of the substrate on In2Se3@N-C also has a good influence on the photocatalytic process of organic transformation.