Photocatalytic degradation of bisphenol-a in aqueous solution by calcined pbo semiconductor irradiated with visible light

Abstract

Oxidative degradation of bisphenol-A in aqueous solution was conducted under visible light irradiation using PbO semiconductor, of which band gap energy was reduced from 2.61 to 1.99 eV, caused by smoothening surface morphology via the calcination treatment. The characteristics of original and reacted PbO (calcined) were illustrated by X-ray diffraction patterns, FE-SEM images, Brunauer–Emmett–Teller specific surface areas, UV-Vis diffuse reflectance spectra and X-ray photoelectron spectra respectively. Experiments were carried out in the batch-wise mode to investigate the influence of various operation variables on the photocatalytic behavior, such as temperature, a dosage of PbO and sodium sulfate concentrations. In this study, bisphenol-A could be almost entirely decomposed through PbO coupled with visible light irradiation, wherein photogenerated holes and hydroxyl radicals were presumed to be principal oxidizing agents. Besides, the removal percentage of bisphenol-A was significantly enhanced on the addition of sodium sulfate, in which sulfate anions were transformed into sulfate radicals via photogenerated holes. On the whole, PbO semiconductors integrated with visible light irradiation appear to be an economical and promising method for disposal of wastewater containing bisphenol-A.