Defects level and internal electric field co-induced direct Z-scheme charge transfer for efficient photocatalytic H2 evolution over ZnIn2S4/In2Se3

Developing rational strategy on inducing efficient direct Z-scheme charge transfer for boosting photocatalytic H2 evolution is stilling a challenging work. In this work, sulfur-deficient ZnIn2S4/In2Se3 (Vs-ZIS/In2Se3) was fabricated, in which, photogenerated electrons in the defect level of Vs-ZIS migrated to the valence band of In2Se3, meanwhile, the interfacial internal electric field provided charge transfer driving force. Under the synergistic effect of defect level and internal electric field, Z-scheme charge transfer was realized in Vs-ZIS/In2Se3, not only accelerated the separation of photocarriers, but also reserved a great deal of photogenerated electrons with intense reducing ability. As a result, the optimized Vs-ZIS/In2Se3 photocatalyst exhibited a visible light-driven H2 evolution rate of 36.53 mmol·g−1·h−1 and an AQE of 17.14 % at 420 nm, about 9.72 and 104.4-folds of that of Vs-ZIS and In2Se3 respectively. This work donates an advanced pattern for inducing direct Z-scheme charge transfer through creating defect level and internal electric field.