Photodegradation of PCB 138 using novel ZnO-SO3H nano semiconductor under visible light

In this study, PCB 138 was chosen to evaluate the impact of photodegradation using newly synthesized ZnO-SO₃H nano semiconductor in the presence of visible light in aqueous solutions. This study focused on the preparation of the ZnO-SO₃H nano photocatalyst. The structures of the nano photocatalysts were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and N₂ adsorption–desorption isotherm analyses. In this study, the effects of the catalyst dose, the zero-charge point, solution pH, and the initial PCB 138 concentration were investigated. FESEM, TEM, and XRD results of the ZnO-SO₃H nano photocatalyst showed that ZnO in the presence of ClSO₃H has changed to a layered and rod structure. Also, the nitrogen adsorption–desorption isotherm has shown that ClSO₃H has changed the structure of commercial ZnO. Based on the results of experiments in batch-mode photoreactor, the optimum amount of the ZnO-SO₃H nano photocatalyst, solution pH, and initial concentration of PCB 138 was 2.5 g/L, 7.2, and 2 ppm, respectively. The photodegradation efficiency of PCB 138 after 1 h with the ZnO-SO₃H nano semiconductor was 78.55, which had a higher efficiency than commercial ZnO.