Morphology- and size-dependent FAPbBr3/WO3 Z-scheme photocatalysts for the controllable photo-oxidation of benzyl alcohol

[Display omitted] •99% selectivity and 49.6% conversion efficiency of benzyl alcohol are realized based on FAPbBr3 and WO3 Z-scheme heterojunction.•59.03% benzoic acid from oxidation of benzyl alcohol is achieved by introducing the quantum confinement effect.•An unreported radical that plays key role in benzyl alcohol oxidation was monitored by in-situ electronic paramagnetic resonance.•Photocatalytic route and rate are strongly depended on the morphology and size design. Photocatalytic benzyl alcohol (BA) oxidation to value-added chemicals by semiconductors has attracted massive attentions due to its industrial interest. In this work, Z-scheme heterojunction photocatalysts composed of FAPbBr3 nanocrystals (NCs) and WO3 with different morphologies are prepared. Benefiting from the strong redox potential and morphological engineering, the Z-scheme heterojunction photocatalyst exhibits an outstanding performance of BA oxidation to benzaldehyde (BD) with 99% selectively. Remarkably, after manipulating the size of FAPbBr3 NCs to quantum dots (QDs), benzoic acid (BZ) as the main product (90% selectivity) of BA oxidation can be generated on the Z-scheme photocatalyst. As revealed by in-situ electronic paramagnetic resonance (EPR), a new radical will be generated over the FAPbBr3 QDs/WO3 which alters the product of benzyl alcohol oxidation form BD to BZ.