Monodisperse perovskite CoSn(OH)6 in-situ grown on NiCo hydroxide nanoflowers with strong interfacial bonds to boost broadband visible-light-driven photocatalytic CO2 reduction

Abstract

Heterojunction engineering is a very prospective approach to modulate the photocatalytic behaviors of semiconductors. Herein, Venus flytrap-like NiCo hydroxide nanoflowers (HNF) with surface modification by different contents of CoSn(OH)6 were fabricated in situ for the first time. Interestingly, CoSn(OH)6 nanocubes (NC) are monodispersed on the nanosheet surface of NiCo HNF. Experimental characterizations and theoretical calculations comprehensively demonstrate the surface Sn atoms of CoSn(OH)6 are effectively embedded into the NiCo HNF interlayers, and co-sharing of the hydroxyl enables intimate contact in the heterointerface of NiCo HNF/CoSn(OH)6 hybrids and thereby largely shortens the charge migrating distance, contributing to an efficient interfacial charge migration and promoting charge separation. The optimized NiCo HNF/CoSn(OH)6 exhibits the remarkably enhanced photocatalytic efficiency for CO2 reduction with a TON of 601.2 and the CO and CH4 yield is about 3 folds that over CoSn(OH)6 NC. DRIFTS reveals the reaction intermediates in the CO2 photocatalytic process and proposes a possible mechanism for photocatalytic CO2 reaction. These findings may pave the way for rational engineering design of non-precious highly-dispersed broadband visible-light-driven CO2 reduction heterostructure catalysts.