An S-scheme heterojunction BiOBr QDs/Bi7O9I3 nanoflowers enabling enhanced photocatalytic oxygen evolution

Abstract

Constructing a heterojunction is an effective strategy to achieve high-efficiency separation of charges, which enhances the photocatalytic performance. Here, we present a 0D/3D S-scheme heterojunction, BiOBr/Bi7O9I3, which was constructed by incorporating highly dispersed BiOBr quantum dots (QDs) onto the surface of Bi7O9I3 nanoflowers. This heterostructure effectively absorbs visible light and enhances the separation of charge carriers significantly via an S-scheme pathway. As a result, the BiOBr/Bi7O9I3 photocatalysts demonstrated an excellent photocatalytic O2 evolution rate, achieving a rate of nearly 1500 μmol h−1 g−1. This work highlights the effectiveness of constructing S-scheme heterojunctions to enhance photocatalytic O2 evolution.