Integrated Photocatalytic and Photoelectrocatalytic Degradation of Organic Dyes Over CuV ₂ O ₆ : Mechanistic Insights and RSM‐Based Optimization

ABSTRACT A CuV ₂ O ₆ photocatalyst was successfully synthesized via a hydrothermal route and tested for the degradation of organic dyes under solar light irradiation. Structural and optical characterizations confirmed the formation of a pure crystalline phase with a direct band gap of 2.08 eV, ensuring efficient visible‐light absorption. To maximize the catalytic performance of the pristine CuV ₂ O ₆ material, operating parameters were systematically optimized using response surface methodology (RSM) combined with a central composite design (CCD). This approach made it possible to reliably estimate linear, quadratic, and interaction effects while reducing the number of experiments required. Under optimized conditions, CuV ₂ O ₆ efficiently removed dyes, achieving 95% degradation of Rhodamine B and 81% of Methyl Orange within 135–150 min. Radical scavenging tests, as well as the band structure analysis, revealed that superoxide radicals (O ₂ • ⁻ ) and photogenerated holes (h ⁺ ) are the major reactive species implicated in dye decomposition, while TOC and COD measurements have shown significant mineralization. Moreover, incorporating CuV ₂ O ₆ into a photoelectrocatalytic setup enhanced charge separation and accelerated decomposition, leading to nearly total pollutant elimination within 90 min for RhB and 110 min for MO. In summary, combining RSM optimization with the PEC approach reveals the potential of pure CuV ₂ O ₆ as an efficient visible light driven wastewater remediation material.