Photocatalytic CO 2 -to-Ethylene Conversion over Bi 2 S 3 /CdS Heterostructures Constructed via Facile Cation Exchange

Solar-driven CO conversion to multicarbon (C ) products has emerged as a key challenge, yet this calls for a systematic investigation on the overall reaction process and mechanism at an atomic level based on the rational design of highly selective photocatalysts. Herein, we report the synthesis of compact Bi S /CdS heterostructures via facile cation exchange, by which a unique pathway of CO -to-C H photoconversion is achieved. Specifically, the BCS-30 shows an optimal C H production rate of 3.49 mol h g based on the regulation of band structures and energy levels of photocatalysts by controlled growth of Bi S at CdS surface. Both experimental and theoretical results (DFT calculations) identify Bi atoms as new catalytic sites for the adsorption of CO and formation of CO- CO dimers that further hydrogenate to produce ethylene. Overall, this work demonstrates vast potentials of delicately designed heterostructures for CO conversion towards C products under mild photocatalytic conditions.