PHOTOCATALYTIC DEGRADATION OF P-NITROANILINE BY NANO-SIZED ZnO-TiO2/Fe3O4 COMPOSITE PHOTOCATALYST

摘要

Nano-sized composite photocatalyst ZnO-TiO2/Fe3O4 was synthesized successfully by coprecipitation and sol-gel-calcination technique. The photocatalyst was characterized by X-ray power diffraction and its photoactivity was tested by the degradation of p-Nitroaniline (pNA). Results of the L6 (45) orthogonal test indicated that the optimal synthesis conditions for the photocatalyst were as follows: the sol-gel aging time, 4 h; molar ratio of nZnO: nTiO2: nFe3O4, 0.2:1:6; calcination temperature, 500 V, and the catalyst calcination time, 2 h. According to the results of the L9 (34) orthogonal experiment, the optimal degradation conditions for the degradation of pNA by the composite photocatalyst were as follows: photo -catalyst dosage, 3 g/L; pH=6; H2O2 dosage, 2.5 mL/L. Under these conditions, when the initial concentration of pNA was 50 mg/L, the photocatalytic degradation efficiency of pNA solution irradiated by a 500 W high-pressure mercury-vapor lamp for 2 h was 90.52%.