Nanocrystalline ZnO doped lanthanide oxide: An efficient photocatalyst for the degradation of diesel pollutant in seawater under visible light irradiation

In this study, a ZnO doped Er2O3 photocatalyst is employed to degrade diesel pollutant in seawater under visible light irradiation. The photocatalyst was prepared by a precipitation method and was characterized by SEM and XRD analysis. The experimental results proved that the nanocrystalline photocatalysts were highly active in the visible region. The photocatalytic degradation efficiency of diesel was analysed by various experimental parameters namely dosage, doping ratio, initial concentration of diesel, pH value, concentration of H2O2 and illumination time. The degradation of diesel pollution in seawater was optimized by orthogonal experiment. According to the results, the removal rate of diesel is less than 30 % without any catalysts (only evaporation). The best effect exists when the dose of catalysts was 0.6 g/L, doping ratio of catalysts was 10%, initial concentration of diesel was 0.2 g/L, pH value was 8, concentration of H2O2 was 10 mg/L, illumination time was 1 h. The removal rate of diesel can reach 99.38 %. This study would make ZnO utilize sunlight more efficiently and accelerate the practical application of photocatalytic technology in organic pollutants treatment region. (paper)