Synthesis, Characterization, and Enhanced Photocatalytic Dye Degradation: Optimizing Graphene-Based ZnO-CdSe Nanocomposites via Response Surface Methodology

This study introduces synthesizing and utilizing a novel rGO-ZnO-CdSe composite for the visible-light-driven photocatalytic degradation of basic red 46 (BR46) dye. Employing a hydrothermal approach for synthesis, the composite underwent detailed characterization using FESEM, XRD, and FTIR. The process of photocatalytic degradation was systematically modeled and refined using response surface methodology (RSM). These conditions, including a 0.05 g photocatalyst loading, 14.05 mg/L initial dye concentration, and a pH level of 7.78, resulted in an average degradation yield of 94.59 %. Further investigations into the effects of different scavengers unveiled the dominant role of •OH radicals in the degradation mechanism. The composite demonstrated excellent recyclability, retaining most of its effectiveness over the fifth cycle with minimal efficiency loss. Additionally, significant TOC removal efficiency indicated thorough mineralization and safety assessments confirmed no significant release of hazardous heavy metals post-degradation. This study underscores the importance of optimizing operational parameters and highlights the composite's environmental safety and sustainability.