In-situ producing CsPbBr nanocrystals on (001)-faceted TiO nanosheets as S‑scheme heterostructure for bifunctional photocatalysis.

Fabricating a cost-effective yet highly active photocatalyst to reduce CO to CO and oxidize benzyl alcohol to benzaldehyde simultaneously, is challenging. Herein, we construct an S-scheme 0D/2D CsPbBr/TiO heterostructure for bifunctional photocatalysis. An in-situ synthetic route is used, which enables the precise integration between CsPbBr nanocrystals and ultrathin TiO nanosheets exposed with (001) facets (termed as TiO-001), resulting in a tightly coupled heterointerface and desirable band offsets. The as-prepared CsPbBr/TiO-001heterojunctions exhibit boosted charge carrier kinetics, particularly, quick carrier separation/transfer and efficient utilization. Experimental results and theoretical calculations validate the S-scheme route in CsPbBr/TiO-001, which allows the enrichment of strongly conserved electrons-holes at conduction and valence bands of CsPbBr and TiO-001, respectively. Consequently, compared to its counterparts, an excellent bifunctional activity (with 24 h reusability) is realized over CsPbBr/TiO-001, where the production rate of CO and benzaldehyde reach up to 78.06 μmol gh and 1.77 mmol gh respectively, without employing any sacrificial agents. This work highlights the development of perovskite-based heterostructures and describes the efficient harnessing of redox potentials and charge carriers towards combined photocatalytic systems.