Ternary photocatalysts based on MOF-derived TiO2 co-decorated with ZnIn2S4 nanosheets and CdS nanoparticles for effective visible light degradation of organic pollutants

One of the feasible strategies to enhance the photocatalytic properties of TiO2 is to broaden the visible light response range and accelerate the separation rate of photo-induced electron–hole (e−–h+) pairs by designing and synthesizing heterostructures using narrow-band-gap semiconductors. In this study, a ternary heterostructure based on MOF-derived TiO2 was first fabricated via the self-sacrificing template method followed by a two-step chemical bath process. The as-obtained CdS/ZnIn2S4/TiO2 ternary heterostructures exhibited better visible-light photocatalytic properties for the degradation of Rhodamine B (RhB) and tetracycline (TC) than single-component and dual-component systems. Among the ternary heterostructures, it was found that the CdS/ZnIn2S4/TiO2-II showed the highest photoreactivity of 95.3% for RhB removal and 91.8% for TC removal within 40 min. In addition, CdS/ZnIn2S4/TiO2-II could maintain its photocatalytic properties during the stability test. The improvement in photocatalytic properties is attributed to the reasonable construction of a ternary heterostructure, which significantly accelerates the separation and transport of photogenerated e−–h+ pairs, improves the specific surface area, and broadens the visible light response range. This study demonstrates a promising strategy for developing ternary heterostructures as effective photocatalysts for the degradation of organic pollutants.