In2O3/In2S3 Heterostructures Derived from In-MOFs with Enhanced Visible Light Photocatalytic Performance for CO2 Reduction

A series of In2O3/In2S3 core-shell heterostructures, derived from metal-organic-frameworks (MOFs), were successfully synthesized via a two-step solvothermal route with different addition amount of sulfur-bearing reagent (L-cysteine, L-Cys), which were used as photocatalysts for CO2 reduction with water vapor. The results indicated that 1.2-In2O3/In2S3 with optimized L-Cys addition amount had the highest production rate of CH4 (14.3 mu mol g(cat)(-1) h(-1)) and CO (2.59 mu mol g(cat)(-1) h(-1)). Pure In2O3 and 2.4-In2O3/In2S3 with excess L-Cys addition exhibited higher H-2 production rate but lowest CO2 photoreduction activity. As the characterizations revealed, amorphous shell with abundant In2O3/In2S3 heterostructures greatly improved the separation efficiency of photo-induced charge carriers and visible light harvesting ability, which promoted the photoreduction of CO2 consequently. However, over-addition of sulfur-bearing reagent destroyed the heterostructures of shell layer and turned them into thickened In2S3 crystal layer. This substitution not only reduced the amount of heterostructures, but also hindered the adsorption of CO2 on the reactive surface.

Automated summary

A series of In2O3/In2S3 core-shell heterostructures were successfully synthesized via a two-step solvothermal route, with the 1.2-In2O3/In2S3 showing the highest CO2 reduction activity when optimized L-Cys addition was used. The over-addition of L-Cys led to the destruction of heterostructures in the shell layer, reducing the adsorption capacity for CO2 on the reactive surface.