محسن منصوری

In this study, the photocatalytic degradation of phenol using zinc oxide(ZnO) as a photocatalystco-doped with lanthanum oxide (LaO), copper oxide(CuO), cerium oxide (CeO2/Ce2O3),and urea (as a source of Nitrogen) was investigated. The catalystnanoparticles were synthesized by the chemical Co-precipitation method in this study. Structural and morphological properties of the synthesized catalyst were characterized by field emission scanning electron microscopy (FESEM)withEnergy dispersive X-Ray spectroscopy (EDX), X-ray diffraction(XRD), BrunauerEmmet Teller specific surface area (BET), Fourier transform infrared (FTIR),UV-visible diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL) techniques. The influence of catalyst dosage, contact time, phenol concentration, irradiation type, and solution PH was examined to achieve maximum degradation efficiency.5 mol % CeO2/Ce2O3, 0.33 weight % N contents, 0.45 g/L catalyst dose, 5 ppm phenol concentration and pH = 9 were the optimum conditions for phenol photocatalytic degradation. Increased phenol concentrations decreased decomposition efficiency. The effect of the utilized (H2O2) content revealed that superoxide and hydroxyl radicals played the most important role in photocatalytic degradation, and the best Vol. of H2O2 (1.62 mM) added was 0.2 ml. The efficiency of photocatalytic degradation ((C0-C)/C0 *100%) was evaluated using a UV-Visible spectrophotometer. It was found by plotting the association between ln (C0/Ct) with irradiation times (t), The pseudo-first-order reaction was found, and the rate constant (K) of the reaction is 0.064 min-1. The used illumination source isa light emitting diode(LED) =50 W, where the photocatalyticdegradation efficiency is close to 99% after 72 min at the optimum condition.A double Z-scheme pattern is proposed as a likely charge transfer mechanism, given that the ZnO-Ce5-N0.33 is a heterostructure composed of Zn1-xCexO1-yNy and Ce2O3 and CeO2.