In situ construction of a direct Z-scheme CdIn 2 S 4 /TiO 2 heterojunction for improving photocatalytic properties

Direct Z-scheme photocatalytic systems driven by visible light to eliminate organic pollutants in wastewater have become important scientific tools in the field of photocatalysis. In this study, a direct Z-scheme CdIn 2 S 4 /TiO 2 heterojunction with high efficiency was prepared through a simple hydrothermal method. Benefiting from the increased visible light response and prolonged lifetime of photoexcited carriers, the as-prepared CdIn 2 S 4 /TiO 2 composites exhibit significantly promoted photocatalytic performance for the degradation of methyl orange (MO) under visible-light illumination ( λ ≥ 420 nm). The CdIn 2 S 4 -25 wt% TiO 2 (25CT) photocatalyst exhibited the highest degradation efficiency (96.2% within 30 min) with a rate constant of 0.1193 min −1 and remarkable stability and repeatability. In the meantime, the study of the photocatalytic mechanism shows that the charge transfer path conforms to the Z-scheme model, in which h + and ˙O 2 − are the main active species. This study provides strong practical support for the preparation of efficient Z-scheme photocatalytic materials by hydrothermal methods.