C as a bridge and Bi as a photothermal converter to trigger visible-light catalytic CO2 reduction over BiOBr by in situ solid-state reduction

Abstract

Synchronously extending the light-harvesting window and accelerating photogenerated carrier migration still present a contradiction in photothermal catalytic CO2 reduction. Herein, BiOBr-based nanosheets (BOB-20) with triple active sites of Bi NPs, amorphous carbon and oxygen vacancies (Ov) were constructed via a in-situ solid-phase reduction. On account of the localized surface plasmon resonance (LSPR) effect of Bi NPs that can serve as electron transport hubs to enhance visible light absorption and induces photothermal effect to raise temperature of catalyst, as well as highly conductive porous C nanoplates as electronic export medium that can speed the separation and transportation of chargers, meanwhile, Ov can promote CO2 adsorption/activation via enhanced local electron states. Ultimately, BOB-20 achieves a CO generation rate as high as 43.99 μmol g -1 under visible light, which is 3.9 times higher than that of the pristine BiOBr (11.15 μmol g -1 ). This study proposes a green and low-cost solvent-free strategy for CO2 conversion strategy that from the synthesis of catalyst to the final application aspect.