UV/Ni–TiO2 nanocatalyst for electrochemical removal of dyes considering operating costs

This paper reports an investigation into the effect of a number of operating factors on the removal of Reactive Red 19 (RR 19), Acid Orange 7 (AO 7), and Acid Red 18 (AR 18) from an aqueous solution through photoelectrocatalysis. Nano-Ni–TiO2 was used as the photocatalyst applied in suspension to achieve a larger catalyst surface area. Photocatalyst dose, dye concentration, pH, bias potential, electrolyte concentration, and temperature were found to be optimum at 0.6 ppm, 30 ppm, 7, 1.6 V, 5 ppm, and 25 °C respectively. Significant reduction was observed in the COD values of the solutions, denoting effective treatment. Photocatalyst efficiency was evaluated using SEM, XRD, and FT-IR techniques. Cost analysis was performed for the treatment process. The energy required by the experiment was supplied by solar cells, meaning that no money had to be spent on electricity.