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

Photothermal 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 mu mol g(-1) h(-1) with no extra heat input. This work provides an insightful guidance for the construction of effective photothermal catalysts for CO(2 )reduction with high solar-to-fuel conversion efficiency.