Highly Selective Ethylene Production from Solar-Driven CO<sub>2</sub> Reduction on the Bi<sub>2</sub>S<sub>3</sub>@In<sub>2</sub>S<sub>3</sub> Catalyst with In–S<sub>V</sub>–Bi Active Sites
Ke Yan, Donghai Wu, Ting Wang, Cong Chen, Shoujie Liu, Yangguang Hu, Chao Gao, Houyang Chen, Benxia Li
Abstract
Photothermal catalysis that utilizes solar energy to not only generate charge carriers but also supply heat input represents a potentially sustainable strategy for the efficient conversion of CO 2 to valuable chemicals. It is highly desirable to develop photothermal catalysts with broadband light absorption across the whole solar spectrum, efficient photothermal conversion, and appropriate active sites. In this work, the Bi 2 S 3 @In 2 S 3 heterostructure catalyst is fabricated via one-step solvothermal synthesis, where Bi 2 S 3 serves as a photothermal material and synchronously affords photoexcited charge carriers. Experimental results indicate that the photoinduced charge carriers trigger H 2 O-assisted CO 2 reduction and the elevated temperature kinetically accelerates the reaction. Furthermore, the tightly bonded heterointerfaces provide unique In–S V –Bi active centers consisting of adjacent Bi and In atoms coupled with sulfur vacancies, which reduces the energy barriers of CO 2 activation and C–C coupling, facilitating the generation and dimerization of CO intermediates for highly selective C 2 H 4 production. The integration of In–S V –Bi active sites and the photothermal effect into the Bi 2 S 3 @In 2 S 3 catalyst induces a high rate of 11.81 μmol g cat –1 h –1 and near 90% selectivity for CO 2 conversion to C 2 H 4 under simulated sunlight without extra heat input. The catalytic mechanism is expounded by in situ characterizations and theoretical calculations. This work would provide some enlightening guidance to construct efficient photothermal catalysts for the direct transformation of CO 2 to multicarbon (C 2+ ) products with solar energy.