Photoelectrochemical degradation of Methylene blue from solution using BiOBr/Bi2S3/TiO2/GO photoanode

Abstract

The photoelectrochemical degradation of methylene blue (MB) dye through the stabilization of BiOBr/Bi2S3/TiO2/GO nanocatalyst was examined. The nanocatalysts were synthesized using the solvothermal method and the spin coating method was applied for the coating. In photoelectrochemical processes, the coated-FTO was used as the anode and the graphite as the cathode. An initial dye concentration of 10 mg/L, the initial pH level of 6, photocatalyst dosage of 0.5 g/L, and irradiation time of 90 min, were the optimal conditions for the photocatalytic degradation. The experimental value of degradation in MB was conceived to be 97.9%. The optimal conditions for the photoelectrochemical degradation of MB include the initial concentration of the dye of 17 mg/L, the initial pH level of 6, the number of coatings of 3 times, and the irradiation time of 90 min, and the experimental value of 98.7% was obtained. The current density produced under optimal conditions was calculated and the effect of the light source and nitrogen gas on the efficiency was observed. The possibility of recycling the photocatalyst up to 4 times in both suspended and stabilized forms, confirms the stability, repeatability, and optimal activity of the photocatalyst. The economic performance was also investigated. According to the trapping tests, holes and hydroxyl radicals were the main active species in the degradation process.