Photocatalytic degradation of bisphenol A in a visible light/TiO2 system

This study evaluates the photodegradation efficiency of bisphenol A (BPA) in a visible light/TiO2 system. TiO2 was generated by the sol–gel method and polyethyleneglycol (PEG) was used as a modulator. The effects of the molecular weight of PEG, the addition percentage of PEG, the pH of the solution and the TiO2 dose were determined. For a given percentage of PEG added, the intensity of anatase followed the order TiO2/PEG600 > TiO2/PEG3500 > TiO2/PEG200. The BPA degradation rates of visible light/TiO2/PEG200 (10%), visible light/TiO2/PEG600 (5%) and visible light/TiO2/PEG3500 (0.5%) at pH 4 were 2.07, 3.01 and 2.90 h− 1, respectively. After 12 h of reaction, the reductions of TOC in visible light/TiO2, visible light/TiO2/PEG200 (10%), visible light/TiO2/PEG600 (5%) and visible light/TiO2/PEG3500 (0.5%) systems were 38%, 56%, 65% and 64%, respectively. The concentrations of hydroxyl radicals in visible light/TiO2, visible light/TiO2/PEG200 (10%), visible light/TiO2/PEG600 (5%) and visible light/TiO2/PEG3500 (0.5%) systems were determined to be 50.1, 88.6, 78.8 and 75.1 μM, respectively. This study finds that adding PEG during the preparation of TiO2 increased the photoactivity of the generated TiO2 however, the optimal PEG addition percentage varied with the molecular weight of PEG.