Enhanced photocatalytic degradation of diazinon by TiO2/ZnO/CuO nanocomposite under solar radiation
Mohammad Malakootian, Mohammad Mahdi Soori
Abstract
ABSTRACT Diazinon which is one of the most widely used toxins and pesticides, is responsible for contaminating surface and ground water sources all over the world. This study aims to determine the photo-catalytic degradation of diazinon using TiO 2 /ZnO/CuO nanocomposite under solar radiation in aqueous solutions. First, TiO 2 /ZnO nanoparticles were synthesized, then they were doped by 0.5%, 1%, and 2% of copper oxide. To characterize nanoparticles, the scanning electron microscope, energy-dispersive X-ray spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, MAP, and zeta potential analysis were conducted; and also the effects of different variables such as copper dopant percent, pH, nanoparticles dose, initial concentration of diazinon and contact time were evaluated on photo-catalytic reaction using one factor at time procedure. The results showed that the dopant percent of copper oxide was effective for removing diazinon so that doping of 0.5%, 1%, and 2% of copper oxide had the efficiency of 53%, 71%, and 61%, respectively, and they were more than uncoated nanoparticles (TiO 2 /ZnO) in the same condition. Based on the results, the highest removal rate of diazinon after 120 min of reaction time was 91% under optimal conditions (pH = 7, 1% copper dopant, and 2 g/L nanoparticles). Therefore, it can be concluded that the photocatalytic process by TiO 2 /ZnO/CuO nanoparticles could effectively eliminate diazinon under real conditions.