In 2 O 3 /In 2 S 3 Heterostructures Derived from In‐MOFs with Enhanced Visible Light Photocatalytic Performance for CO 2 Reduction

Abstract A series of In 2 O 3 /In 2 S 3 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 CO 2 reduction with water vapor. The results indicated that 1.2‐In 2 O 3 /In 2 S 3 with optimized L‐Cys addition amount had the highest production rate of CH 4 (14.3 μmol g cat −1 h −1 ) and CO (2.59 μmol g cat −1 h −1 ). Pure In 2 O 3 and 2.4‐In 2 O 3 /In 2 S 3 with excess L‐Cys addition exhibited higher H 2 production rate but lowest CO 2 photoreduction activity. As the characterizations revealed, amorphous shell with abundant In 2 O 3 /In 2 S 3 heterostructures greatly improved the separation efficiency of photo‐induced charge carriers and visible light harvesting ability, which promoted the photoreduction of CO 2 consequently. However, over‐addition of sulfur‐bearing reagent destroyed the heterostructures of shell layer and turned them into thickened In 2 S 3 crystal layer. This substitution not only reduced the amount of heterostructures, but also hindered the adsorption of CO 2 on the reactive surface.