Green-Fueled synthesis of rGO/CuO for catalytic degradation of methyl violet dye

This study presents the green synthesis of copper oxide (CuO) through an eco-friendly solution combustion method, utilizing lemongrass as a natural fuel source. The rGO/CuO composite was prepared via a simple reflux process, emphasizing environmental sustainability. Comprehensive characterization of the synthesized CuO and rGO/CuO composites was conducted using techniques such as XRD, SEM, FTIR, PL, HR-TEM, EDX, and UV-Vis’s spectroscopy. The photocatalytic efficiency of the rGO/CuO composite was tested for the degradation of Methyl Violet (MV) dye, achieving an impressive degradation rate of 98.87% and following first-order kinetic behavior. The half-life (t₁/₂) of the reaction was calculated to be 18.17 min, with a rate constant (k) of 0.0398 min⁻ 1 . Various parameters affecting photocatalytic performance, including pH, dye concentration, light source, and catalyst dosage, were systematically investigated. Scavenger experiments were conducted to determine the active species involved in the degradation process, and total organic carbon (TOC) removal was measured to assess mineralization efficiency. The catalyst's reusability was also evaluated, confirming its potential for long-term use in sustainable environmental remediation applications. Graphical Abstract of Methyl Violet dye degradation in the presence of CuO and rGO/CuO by UV light irradiation. • CuO nanoparticle was prepared through solution combustion method by using lemon grass plant as a fuel. • rGO/CuO composite were prepared through simple reflux method, by using less hazardous chemical to the environment. • The Methyl Violet dye degradation using the prepared rGO/CuO about 98.87 %, and follows 1 st order kinetic rate of the reaction. • Furthermore, the half-life period, pH studies, % TOC, Quenching experiment, recyclability of the catalyst were investigated in the studies.