Promoted selectivity of photocatalytic CO2 reduction to C2H4 via hybrid CuxCoSy possessing dual unsaturated sites

Abstract

Ethylene production by CO2 reduction is sluggish because the repulsive dipole-dipole interaction and 12 proton-coupled electron-transfer steps consecutively. Amorphous structured photocatalysts possess few grain boundaries and abundant unsaturated sites, accelerating the reaction efficiency from the angle of dynamics and thermodynamics, which still not yet be used in PCR to C2 products currently. Herein, an amorphous CuxCoSy composed of the minority crystalline CuCo2S4 is fabricated to realize an excellent C2H4 selectivity in terms of Relectron (94.9%). Unsaturated Co and S play the key roles in the improved efficiency of C2H4 generation. C-C coupling is achieved via shortening Co-S bonds distance, and *CO-*CO coupling barrier is decreased by more electrons accumulated on unsaturated S. Water is adsorbed on Co adjacent to S and provide protons for *COCO to form *CH2 = C. This work paves a new way for broadening the efficient of C2H4 photocatalytic evolution using amorphous photocatalyst.