A Zn-doped CuS–TiO₂ hetero-structured photocatalyst was synthesized via a simple hydrothermal approach to achieve efficient degradation of organic dyes under visible light. Structural and optical characterizations, including XRD, FTIR, UV–vis spectroscopy, SEM, and EDX, confirmed the successful formation of the heterojunction and incorporation of the dopant without secondary phases. The composite exhibited a broad absorption spectrum extending into the visible range and a high specific surface area of 82.63 m²/g with mesoporous features, as evidenced by BET analysis. SEM revealed a heterogeneous morphology composed of nanosheets, rods, and spherical aggregates that provide enhanced surface roughness and active sites. Photocatalytic performance was evaluated using methylene blue as a model pollutant under natural sunlight, where the doped composite (30 mg) achieved nearly 98% degradation within 60 minutes. The improved activity is attributed to the synergistic effect between CuS and TiO₂, Zn-induced band gap modulation, and more effective charge separation across the heterojunction interface. Furthermore, the catalyst retained its performance over six reuse cycles, indicating good stability and reusability. These results suggest that Zn-doped CuS–TiO₂ is a promising photocatalyst for solar-driven wastewater treatment applications.

Keywords: Zn-Doped CuS-TiO₂; Photocatalyst; Heterostructure; Dye Degradation;