Coating of anatase titania on clinoptilolite by metal organic chemical vapor deposition method: enhanced mesoporosity and photocatalytic activity (original) (raw)

Clinoptilolite-supported TiO 2 (TiO 2 /CP MOCVD ) has been synthesized by metal organic chemical vapor deposition method (MOCVD). Titanium precursor was evaporated at 110 °C under nitrogen flow rate to promote the surface interaction between titanium species and clinoptilolite. The effect of titanium precursor on the crystalline structure and the surface area of clinoptilolite were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), transformed infrared spectroscopy (FT-IR), Raman spectroscopy, and Brunauer-Emmett-Teller measurement. XRD and SEM results indicate that TiO 2 precursor interacted with the support, decreasing the crystallinity of the clinoptilolite. The analysis by FT-IR spectroscopy further confirms that the titanium species were bound to clinoptilolite through Ti-O-Si bonds. The TiO 2 /CP MOCVD catalyst showed a mesoporous structure with the distribution of pores in several dimensions 3.7-7.1 nm, with high specific surface area (~ 471 m 2 /g). MOCVD improved the adsorption capacity of the catalyst surface towards the pollutants. TiO 2 / CP MOCVD particles turn yellow after adsorption of salicylic acid. The development of the yellow color is a clear indication of the formation of charge transfer titanium (IV) salicylate surface complex. Photocatalytic decomposition of SA in aqueous solution was carried out using TiO 2 /CP MOCVD . Experimental results revealed that TiO 2 /CP MOCVD required shorter irradiation time (120 min) for complete decomposition of SA than commercial P25 Degussa and TiO 2 /CP imp (clinoptilolite-supported TiO 2 using impregnation method). The TiO 2 /CP MOCVD can be recycled at least four times without loss in activity, indicating their magnificent stability.