Easy simultaneous synthesis-immobilization of nanosized CuO-ZnO on perlite as a photocatalyst for degradation of acid orange 7 from aqueous solution in the presence of visible light

In order to improve the photocatalytic activity, the researchers have loaded some metals or metal oxides on semiconductors such as TiO2 and ZnO surface. This study investigated the degradation of acid orange 7 (AO7) from aqueous solution by prepared nanosized CuO-ZnO immobilized on expanded perlite (nCuO-ZnO-P) as a photocatalyst in the presence of visible light. First, nCuO-ZnO-P was simultaneously synthesized-immobilized by pyrolysis of previously adsorbed Cu2+ and Zn2+ on perlite at 723.15 K in oven. The results showed that, unlike ZnO, the prepared nanosized photocatalyst has an effective photocatalytic activity in the presence of visible light. The effective parameters on AO7 degradation which were evaluated in the designed batch photoreactor included initial concentration of AO7 (C-0), pH, the granule size of used perlite for immobilization (D), and temperature (T). It was found that the content of degradation was followed by increasing order: C-0 = 15 > 25 > 35 > 45 > 55 mg l(-1), pH 7 > 8 > 9 > 6 > 5, D = 0.50 > 0.75 > 1.00 > 1.25 > 1.50 mm, and T = 318.15 > 308.15 > 298.15 > 288.15 > 278.15 K.