A tube-like dual Z-scheme indium oxide@indium phosphide/cuprous oxide photocatalyst based on metal-organic framework...

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.