Mn0.05Cd0.95S/Cu2SeI p-n heterojunction with high-conductivity for efficient photocatalytic hydrogen evolution

It is undoubtedly that constructing heterojunction on the surface of semiconductor materials is an effective way to improve the performance of photocatalysts. Here, Cu2SeI nanospheres were dispersed on the surface of Mn0.05Cd0.95S nanoparticles constructed a p-n heterojunction photocatalyst with high conductivity. Firstly, SEM and TEM showed that the load of Cu2SeI nanospheres successfully formed a close contact on the surface of MCS, which was conducive to the rapid charge transfer between the two. Under visible light irradiation, Na2S/Na2SO3 (0.35 M/0.25 M) was used as sacrifice reagent for hydrogen production. The results showed that the construction of p-n heterojunction was beneficial to charge transfer and the hydrogen evolution ability of the composite catalyst was greatly improve, the 3%MCS/Cu2SeI showed the best hydrogen production activity reaching 677.4 lmol after 5 h, it is 12.3 times higher than that of single catalyst MCS, In addition, the results of X-ray photoelectron spectroscopy (XPS) show that the binding energies of the elements in the composite catalysts are different compared with those in the catalysts alone, indicating that there is a interaction between the catalysts. Through the analysis of photo electrochemical and fluorescence spectra, the charge transfer kinetics of the composite catalyst was explained and discussed in depth. On the basis of the above analysis results, the possible photocatalytic reaction mechanism of the composite catalyst was proposed, and the mechanism was analyzed and discussed. This work has undoubtedly made a further improvement for the activity of photocatalytic hydrogen production. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

Constructing heterojunctions on semiconductor materials surface is an effective way to improve photocatalyst performance. In this study, Cu2SeI nanospheres dispersed on Mn0.05Cd0.95S nanoparticles surface forming a p-n heterojunction photocatalyst with enhanced hydrogen production activity. The composite catalyst showed significantly improved hydrogen evolution ability, with the best activity reaching 677.4 μmol.