This study evaluates the photodegradation efficiency of bisphenol A (BPA) in a visible light/TiO 2 system. TiO 2 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 TiO 2 dose were determined. For a given percentage of PEG added, the intensity of anatase followed the order TiO 2/PEG600 > TiO 2/PEG3500 > TiO 2/PEG200. The BPA degradation rates of visible light/TiO 2/PEG200 (10%), visible light/TiO 2/PEG600 (5%) and visible light/TiO 2/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/TiO 2, visible light/TiO 2/PEG200 (10%), visible light/TiO 2/PEG600 (5%) and visible light/TiO 2/PEG3500 (0.5%) systems were 38%, 56%, 65% and 64%, respectively. The concentrations of hydroxyl radicals in visible light/TiO 2, visible light/TiO 2/PEG200 (10%), visible light/TiO 2/PEG600 (5%) and visible light/TiO 2/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 TiO 2 increased the photoactivity of the generated TiO 2 however, the optimal PEG addition percentage varied with the molecular weight of PEG.