Complexed Semiconductor Cores Activate Hexaniobate Ligands as Nucleophilic Sites for Solar-Light Reduction of CO2 by Water

Identifier:  imarina:9282479

Handle: https://hdl.handle.net/20.500.11797/imarina9282479

Authors:  Zhang, GY; Wang, F; Tubul, T; Baranov, M; Leffler, N; Neyman, A; Poblet, JM; Weinstock, IA

Abstract:
Although pure and functionalized solid-state polyniobates such as layered perovskites and niobate nanosheets are photocatalysts for renewable-energy processes, analogous reactions by molecular polyoxoniobate cluster-anions are nearly absent from the literature. We now report that under simulated solar light, hexaniobate cluster-anion encapsulated 30-NiII-ion "fragments" of surface-protonated cubic-phase-like NiO cores activate the hexaniobate ligands towards CO2 reduction by water. Photoexcitation of the NiO cores promotes charge-transfer reduction of NbV to NbIV, increasing electron density at bridging oxo atoms of Nb-m-O-Nb linkages that bind and convert CO2 to CO. Photogenerated NiO "holes" simultaneously oxidize water to dioxygen. The findings point to molecular complexation of suitable semiconductor "fragments" as a general method for utilizing electron-dense polyoxoniobate anions as nucleophilic photocatalysts for solar-light driven activation and reduction of small molecules.© 2022 Wiley-VCH GmbH.