Fabrication of CuInS2 quantum dot-modified TiO2 Z-scheme heterojunction photocatalyst for efficient degradation of 2,4-dichlorophenol

The construction of heterojunction photocatalysts featuring broad spectral response and efficient charge separation was crucial for the decomposition of organic pollutants. In this work, CuInS 2 quantum dot (CIS QDs)-modified TiO 2 nanorods (CISQ/TiO 2 ) composite photocatalysts with varying compositions were fabricated via a facile solvothermal process. Their visible-light-driven photocatalytic activity was subsequently evaluated using the degradation of 2,4-dichlorophenol (2,4-DCP) as a model reaction. The results indicated that when the CIS QDs loading was 10 wt%, the photocatalytic activity was significantly enhanced. A series of characterizations revealed that the improved activity arose from the synergistic effects of the narrow-band-gap CIS QDs, which broadened the light absorption spectrum of TiO 2 and thereby increased light utilization. Furthermore, the proposed Z-scheme-like charge transfer accelerated the migration of photogenerated charge carriers while preserving the high redox potential of the system. This work demonstrated a facile strategy for constructing high-performance TiO 2 -based composite photocatalysts, with significant implications for environmental remediation.