Effect of inorganic anions on Rhodamine B removal under visible light irradiation using Bi2O3/Ti rotating disk reactor

In this study, Bi2O3 with band gap energy of 2.6 eV was coated on a Ti disk and used in a rotating disk reactor to treat 10 mg L−1 Rhodamine B (RB) solution under UV and visible light irradiation. The effects of different inorganic anions (including CO32-, S2−, SO42-, F− and Cl−) were investigated and the results shown that the color removal efficiency could be greatly improved in the presence of Cl−. RB adsorption capacity could be enhanced when Cl− was added and RB could further be degraded due to indirect dye self-photosensitization under visible light irradiation. The radicals generated during the reaction were detected by adding radical trapping agents and other experimental conditions like Cl− concentration, rotating speed and pH of the process were investigated and optimized.

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► RB was degraded using Bi2O3/Ti rotating disk reactor under visible light irradiation.
► Effects of different inorganic anions F-,Cl-,S2-,CO32-,SO42- were investigated.
► RB adsorption capacity could be enhanced in the presence of Cl−.
► RB removal efficiency was greatly enhanced due to indirect dye photosensitization.
► The large amount of Cl− in tap water could also be utilized to degrade RB.