Synthesis and photocatalytic performance of g-C<sub>3</sub>N<sub>4</sub>-CuO-ZnO for efficient degradation of crystal violet (CV) and methyl orange (MO) dyes under sunlight irradiation
Sidra Pervaiz, Muhammad Saeed, Mohamed A. Habila, Muhammad Asghar Jamal, Atta ul Haq, Iltaf Khan, Mohsin Javed
Abstract
In the present study, a g-C<sub>3</sub>N<sub>4</sub>-CuO-ZnO heterojunction was successfully synthesized using a cost-effective co-precipitation method and evaluated for its photocatalytic efficiency in degrading crystal violet (CV) and methyl orange (MO) dyes under sunlight irradiation. Comprehensive characterization through XRD, FTIR, SEM, and TGA confirmed the successful formation of the heterojunction, revealing enhanced structural, morphological, and thermal properties. Photocatalytic performance studies showed remarkable degradation efficiencies of 99.26% for CV and 96.84% for MO within 180 min, significantly outperforming individual g-C<sub>3</sub>N<sub>4</sub>, CuO, and ZnO catalysts. The optimized conditions—including pH, catalyst dosage, and reaction kinetics—highlighted the robustness and adaptability of the synthesized catalyst. The superior performance is attributed to the separation and reduction in recombination of electrons and holes, driven by an S-scheme charge transfer mechanism. These findings demonstrate the potential of g-C<sub>3</sub>N<sub>4</sub>-CuO-ZnO as an effective and sustainable catalyst for tackling dyes in wastewater, offering a promising avenue for environmental remediation.