Photocatalytic Oxidative Coupling of Benzylamine to Schiff Base over 0D/2D CdS/CdIn2S4 Heterojunction

To eliminate the usage of traditional fossil fuels, the concept of renewable energy sources to synthesize organic products has been increasingly accepted to achieve peak carbon emission and eventually carbon neutrality. Conversion of solar energy into chemical energy is considered one of the promising and sustainable paradigms to synthesize green chemicals with minimized negative environmental influence. Constructing a suitable semiconductor structure with proper energy-level alignments is an essential prerequisite to improving photocatalytic efficiency. Herein, a series of 0D/2D CdS/CdIn2S4 composites are synthesized by two-step procedures, which can improve the separation rate of photoinduced carriers and enhance the photocatalytic homocoupling oxidation of benzylamine to highly value-added N-benzylidenebenzylamine efficiency. As a result, the optimized 5wt% CdS/CdIn2S4 composite exhibits the highest benzylidenebenzylamine yield of 164.2 mu mol under visible light irradiation for 1 h, which is approximate to 1.8 and 1.6 times than those of undecorated CdS and CdIn2S4. The synergistic effect between 0D CdS and 2D CdIn2S4 is comprehensively characterized, and the faster spatial separation and migration of photogenerated electron-hole pairs contributed to the improved photocatalytic performance. This work can open up insight into construing 0D/2D heterojunctions for efficient photocatalytic organic synthesis in an economically viable and environment-friendly way.