Construction of 0D/1D CdS/g-C3N4 Z-scheme heterojunction for highly selective photocatalytic benzylamine oxidative coupling

The efficient solar-to-chemical energy conversion system is a green and cost-effective approach for producing high-value-added chemicals in chemical industry, which is highly demanded to develop. Photocatalytic C-N coupling of benzylamine into economic N-benzylidenebenzylamine is a great po-tential method for alternative conventional organic synthesis. In this work, a zero-dimensional/one-dimensional CdS/g-C3N4 Z-scheme heterojunction was constructed via in situ growing CdS quantum dot onto g-C3N4 nanorod surface for enhancing the spatial separation of charge carriers and maintaining the strong redox ability of the photogenerated charges and applied simultaneously in photocatalytic C-N coupling of benzylamine. This enables 20 wt% CdS/g-C3N4 to exhibit a remarkable photocatalytic per-formance enhancement for the production of C-N coupled product of benzylamine with the optimal yield of 199.79 mmol which is approximately 4.3 folds than those of pristine g-C3N4 under 2 h visible irradiation. Moreover, benzylamine conversion of approximately 90% within 100 h can be obtained in a gram scale-up reaction. By means of controlled photoelectric chemistry and in situ electron spin reso-nance spectroscopy experiments, possible spatial photogenerated charges separation and benzylamine conversion mechanisms on the Z-scheme junction were investigated in detail. This work paves a promising strategy for constructing zero-dimensional/one-dimensional Z-scheme heterojunction for the photocatalytic synthesis of high-value-added products.(c) 2023 Elsevier Ltd. All rights reserved.

Automated summary

In this work, a zero-dimensional/one-dimensional CdS/g-C3N4 Z-scheme heterojunction was constructed to enhance the spatial separation of charge carriers and maintain the strong redox ability of the photogenerated charges for photocatalytic C-N coupling of benzylamine. The CdS/g-C3N4 exhibited a remarkable photocatalytic performance enhancement, achieving a yield of 199.79 mmol, approximately 4.3 times higher than pristine g-C3N4 under visible irradiation for 2 hours. The study also investigated the spatial charge separation and benzylamine conversion mechanisms on the Z-scheme junction. This work provides a promising strategy for the synthesis of high-value-added products through photocatalysis.