Facilitating charge transfer through an atomic coherent interface of a novel direct Z-scheme BiVO@CuSnS heterojunction to boost photocatalytic performance

• Published in: Nanoscale 2022-08, Vol.14 (32), p.11664-11675
• Main Authors: Liu, Fangting, Chen, Chengcheng, Zhang, Qiaoyu, Zhang, Zhengguo, Fang, Xiaoming
• Format: Article
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/d2nr02536a

Direct Z-scheme photocatalytic systems are very promising composite photocatalysts, and their photocatalytic performance is highly associated with the quality of the interface within them. Herein, a novel direct Z-scheme heterojunction with a coherent interface has been presented for the first time. Specifically, the heterojunction was constructed by dispersing pre-prepared BiVO 4 crystals into the reaction system to synthesize Cu 3 SnS 4 , followed by a hydrothermal reaction. It is shown that Cu 3 SnS 4 was deposited on the surface of each pre-prepared BiVO 4 crystal as a thin layer via heterogeneous nucleation to acquire a core-shell heterojunction. The BiVO 4 @Cu 3 SnS 4 heterojunction was found to possess an atomic coherent interface, which is formed through the bonding between the (121) plane of BiVO 4 and the (112) plane of Cu 3 SnS 4 , originating from the matching in the crystalline lattice between the two planes. The coherent interface facilitated the charge transfer from Cu 3 SnS 4 to BiVO 4 owing to the difference in their Fermi levels, thereby forming a built-in electric field pointing from Cu 3 SnS 4 to BiVO 4 . Reduced fluorescence emission and a shortened carrier lifetime reveal an obvious reduction in the inter-band charge recombination for the optimal BVO@CTS-0.19 sample. Consequently, BVO@CTS-0.19 shows remarkably enhanced photocatalytic performance in MO degradation, Cr 6+ reduction and oxygen evolution. The Z-scheme charge transfer mechanism for BVO@CTS-0.19 was verified by a suite of techniques. This work provides a universal strategy for building a coherent interface to develop high-performance direct Z-scheme heterojunctions. Cu 3 SnS 4 was deposited on the surface of each BiVO 4 crystal to acquire a core-shell direct Z-scheme heterojunction with an atomic coherent interface, which interface facilitated the charge transfer and thus led to much enhanced photocatalytic performance.