In-situ topotactic synthesis of decahedron BiVO4/2D networks Bi2S3 heterojunctions for efficient Cr(VI) reduction: Improved charge separation and imaged at the single-particle level

Epitaxial heterostructure has an optimized interfacial electronic structure compared to the traditional random heterostructures. However, accurately monitoring the interfacial charge transfer dynamics remains a grand challenge. We report here that single-particle spectroscopy techniques address this challenge by performing photoluminescence (PL) lifetime imaging and spectral fitting of interfacial micro/nano regions. A novel facet-selective BiVO4/2D nano-network Bi2S3 heterostructure is synthesized by a simple hydrothermal method. Single-particle PL spectroscopy shows that the PL emission at the oriented epitaxial heterojunction interface in BVO/S-O is weakened, and the PL lifetime increases by 213 % and 105 % compared to a single BiVO4 and random heterojunction particles, respectively, indicating that the topological heterojunction interface effectively promotes the separation of charge carriers. In addition, the possible mechanism of photocatalysis was also discussed in detail. Our work reveals the advantages of unique spatial structures and topological epitaxial interfaces in charge separation, which has great prospects for photocatalytic applications.