Rational design of Ag/CuO@ZnIn2S4 S-scheme plasmonic photocatalyst for highly selective CO2 conversion

Designing S-scheme heterojunctions is an effective method to improve the charge localization on the surface of photocatalysts. Their effective charge transport routes can be enhanced with the help of interfacial noble metal nanoparticles. Herein, an Ag/CuO@ZnIn2S4 plasma S-scheme heterojunction with heterogeneous interfacial covalent bonds was successfully designed. The 15% Ag/CuO@ZnIn2S4 has promising photocatalytic performance and stability with the highest CO and CH4 yields of 6.9 and 54.4 µmol g−1 h−1 and CH4 selectivity of 92.8%. It is evidenced that the photogenerated charge can be efficiently separated and transported due to the influence of both the S-scheme electron migration mode and the Cu-S covalent bond. The process is further accelerated by using precious metals as cocatalysts, which can then selectively convert CO2 into CH4. This research is expected to provide helpful information for engineering S-scheme heterojunction photocatalysts and investigating their charge transfer kinetics.