A Three‐in‐One Integrated Cs3Bi2Br9@Co3O4 Heterostructure with Photoinduced Self‐Heating Effect for Synergistically Enhancing the Photothermal CO2 Reduction

Abstract

AbstractPhotothermal catalysis, which applies solar energy to produce photogenerated e−/h+ pairs as well as provide heat input, is recognized as a promising technology for high conversion efficiency of CO2 to value‐added solar fuels. In this work, a “shooting three birds with one stone” approach is demonstrated to significantly enhance the photothermal CO2 reduction over the Cs3Bi2Br9@Co3O4 (CBB@Co3O4) heterostructure. Initially, Co3O4 with photoinduced self‐heating effect serves as a photothermal material to elevate the temperature of the photocatalyst, which kinetically accelerates the catalytic reaction. Meanwhile, a p–n heterojunction is constructed between the p‐type Co3O4 and n‐type Cs3Bi2Br9 semiconductors, which has an intrinsic built‐in electric field (BEF) to facilitate the separation of photogenerated e−/h+ pairs. Furthermore, the mesoporous Co3O4 matrix can afford abundant active sites for promoting adsorption/activation of CO2 molecules. Benefiting from these synergistic effects, the as‐developed CBB@Co3O4 heterostructure achieves an impressive CO2‐to‐CO conversion rate of 168.56 µmol g−1 h−1 with no extra heat input. This work provides an insightful guidance for the construction of effective photothermal catalysts for CO2 reduction with high solar‐to‐fuel conversion efficiency.