Preparation and characterization of supported ZnO photocatalyst by zincate method

Abstract

Supported ZnO film photocatalysts are prepared on glass and ceramic substrates by zincate method. Prepared ZnO films are seen rather strongly durable. They resist to chemical dissolution in a broad range of pH from 3 to 10. Various physical tests are conducted to measure the relevant characteristics of the films. Band gap of ZnO film is Calculated as 3.24eV. SEM analysis shows that the ZnO film has granular morphology with uniform particle size about 300-400 nm. The film thickness is calculated as 1.41 mu m after twenty coating cycles and the thickness of the thin film per cycle was approximately 70 turn. Photochemical activity tests are performed by measuring photodecolorization rate of methyl orange solution. First order rate constants are correlated to principal process parameters. The results show that ceramic is the preferable supporting material with high activity. According to simulation study, the photocatalytic activity of film coated on ceramic ring of 8 mm diameter is nearly equal to the activity of powder ZnO slurry of 120 mg/dm(3) density. It carried out about decolorization 65% in 3 h. The calculations show that it is possible to prepare ZnO film on ceramic ring with similar activity as powder ZnO. (C) 2009 Elsevier B.V. All Fights reserved.