A tube-like dual Z-scheme indium oxide@indium phosphide/cuprous oxide photocatalyst based on metal–organic framework for efficient CO2 reduction with water

Developing a photocatalyst for efficient reduction of carbon dioxide (CO2) is a long-term goal to address global climate change. In this work, a tube-like indium oxide@indium phosphide/cuprous oxide (In2O3@InP/Cu2O) photocatalyst was prepared by annealing-phosphidation of In-Materials of Institute Lavoisier-68 (In-MIL-68) followed by electrodeposition of Cu2O, which was used to reduce CO2 with water under light irradiation. Partial phosphidation of In2O3 endowed In2O3@InP/Cu2O with strong light-harvesting ability. The In2O3@InP heterojunction combined with in situ loaded Cu2O provided a dual Z-scheme heterojunction for efficient electrons-holes separation. Under the synergisms of each component, the optimized In2O3@InP60/Cu2O-1 exhibited strong adsorption of CO2 and excellent photocatalytic performance in CO2 reduction. The yields of CO and CH4 were 13.7 and 38.8 μmol g-1, respectively, after 5 h simulated light illumination, higher than the corresponding yields with In2O3 (CO: 7.2 μmol g-1, CH4: 13.2 μmol g-1). This study may provide some insights into the design of specific ternary photocatalysts with dual Z-scheme charge transfer mode for CO2 reduction.