CO 2 Photoreduction into C 2 Fuels Steered by Heteroatom Pair Sites in M x O y @Bi 2 S 3 Heterojunction

Synthesis of ethylene (C 2 H 4 ) through carbon dioxide (CO 2 ) photoreduction is predominantly constrained by the kinetic difficulties in C–C coupling. Herein, we develop a universal strategy for C 2 H 4 synthesis from CO 2 photoreduction over a series of M x O y @Bi 2 S 3 heterojunctions in which the M x O y @Bi 2 S 3 heterojunction contain charge-asymmetrical M–Bi pair sites for enhanced C–C coupling. As a prototype, Bi 2 S 3 nanorod-based heterojunctions with wide-period and multigroup metal oxides (Bi 2 O 3 @Bi 2 S 3, In 2 O 3 @Bi 2 S 3, ZnO@Bi 2 S 3, and SnO 2 @Bi 2 S 3 heterojunctions) are synthesized through a simple and effective strategy. Bader charge calculations confirm the presence of charge-asymmetrical M–Bi pair sites at the interface of the M x O y @Bi 2 S 3 heterojunction Further density functional theory (DFT) computations disclose that the C–C coupling turns from a nonspontaneous endothermic process to a spontaneous exothermic process after the construction of heterojunctions, suggesting the feasibility of generating C 2 products through CO 2 photoreduction on M x O y @Bi 2 S 3 heterojunctions. Therefore, all the M x O y @Bi 2 S 3 heterojunction can realize CO 2 photoreduction into C 2 H 4, whereas the individual Bi 2 O 3, In 2 O 3, ZnO, and SnO 2 nanoparticles can only produce carbon monoxide as their product. This proposed universal strategy is expected to prepare a highly active heterojunction for C 2 H 4 photosynthesis from CO 2 reduction.