School of Chemical and Petroleum Engineering - Department of Chemical Engineering - Shiraz University

Preparation and application of CoMgAl-hydrotalcites have been studied. In this paper CoMgAl-LDHs photocatalysts were prepared by co-precipitation. Various techniques such as UV–visible spectrometry (UV–vis), BET, diferential thermal gravimetric analysis, scanning electron microscopy analysis and X-ray difraction were used to investigate the catalytic activity, structure, and composition of the prepared samples. The photocatalysts were developed as layered double hydroxides (LDHs) due to their layered structure with OH−. In the paper, specifc surface area, thermal stability, absorption of visible light, and layered structure (crystal phase) were characterized by nitrogen adsorption–desorption method, diferential thermal gravimetric analysis, UV–vis methods and X-rays difraction. The results indicated that CoMgAl-LDHs caused photocatalytic degradation of methyl orange, rhodamine talcum, and methylene blue. Initially 1 g/L of the photocatalyst was used to degrade 40 mg/L of methyl orange, it was observed that 85.7% of the methyl orange was degraded at an illumination time of 300 min. However, the degradation of rhodamine and methylene blue was not good and did not give better results as that of methyl orange.