Defect-rich and electron-rich mesoporous Ti-MOFs based NH2-MIL-125(Ti)@ZnIn2S4/CdS hierarchical tandem heterojunctions with improved charge separation and enhanced solar-driven photocatalytic performance

Abstract

Defective-rich and electron-rich mesoporous NH2-MIL-125(Ti)@ZnIn2S4/CdS hierarchical tandem heterojunctions were fabricated through two-step solvothermal and one-step hydrothermal strategies. The interface with electron enrichment can cause active interface reaction, fast transfer and separation of charge carriers and restrain the photocorrosion of CdS. ZnIn2S4, as a bridge to connect Ti-MOFs and CdS, favors the separation of charge carriers and forms tandem heterojunctions. The as-prepared photocatalyst has a relative large surface area of ∼877.0 m2 g−1 and a narrow band gap of ∼1.84 eV, which could absorb visible light efficiently. Furthermore, it exhibits a high photocatalytic hydrogen generation rate which was increased to 2.367 mmol g−1 h−1 and the high photocatalytic degradation efficiency for 2,6-dichlorophen and 2,4,5-trichlorophenol which were 98.6% and 97.5%, respectively. Additionally, recycling text for several cycles indicates the high stability. This novel Ti-MOFs based core@shell hierarchical tandem heterojunctions may offer a new insight for fabricating high-performance heterojunctions for multi-channel charges transfer.