Hydrothermal synthesis of mesoporous TiO2 nanoparticles for enhanced photocatalytic degradation of organic dye

In this work, mesoporous TiO2 nanoparticle photocatalyst has been prepared by hydrothermal method using titanium tetrachloride as precursor. The resulting photocatalysts have been characterized using X-ray diffraction (XRD), nitrogen adsorption-desorption analyses, RAMAN spectroscopy, Transmission Electron Microscopy (TEM) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The results showed that the synthesized 2 OiT was anatase phase and mesoporous with specific surface 133.45 m2/g. The decomposition of methylene blue dye under the influence of ultraviolet light was used to test the photocatalytic performance of the produced TiO2 photocatalyst. The photocatalytic activity of the TiO2 photocatalyst for the breakdown of methylene blue dye was significantly higher than that of the commercial TiO2 P25 used as a reference. Moreover, the prepared photocatalyst was stable and reusable. The larger surface area of hydrothermally produced TiO2 was the reason for this enhanced photocatalytic activity. As a result, it is expected that this approach of photocatalytically active semiconducting nanocatalysts will be used in industry to eliminate undesired organics from the environment

Hydrothermal synthesis of mesoporous TiO2 nanoparticles for enhanced photocatalytic degradation of organic dye

320-330In this work, mesoporous TiO2 nanoparticle photocatalyst has been prepared by hydrothermal method using titanium tetrachloride as precursor. The resulting photocatalysts have been characterized using X-ray diffraction (XRD), nitrogen adsorption-desorption analyses, RAMAN spectroscopy, Transmission Electron Microscopy (TEM) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The results showed that the synthesized 2 OiT was anatase phase and mesoporous with specific surface 133.45 m2/g. The decomposition of methylene blue dye under the influence of ultraviolet light was used to test the photocatalytic performance of the produced TiO2 photocatalyst. The photocatalytic activity of the TiO2 photocatalyst for the breakdown of methylene blue dye was significantly higher than that of the commercial TiO2 P25 used as a reference. Moreover, the prepared photocatalyst was stable and reusable. The larger surface area of hydrothermally produced TiO2 was the reason for this enhanced photocatalytic activity. As a result, it is expected that this approach of photocatalytically active semiconducting nanocatalysts will be used in industry to eliminate undesired organics from the environment

pH dependent electro-oxidation of arsenite on gold surface: Relative kinetics and sensitivity

A detailed kinetic investigation of As(III) oxidation was performed on gold surface within pH between ∼3.0 and ∼9.0. It was found that the As(III) oxidation on the gold surface follows a purely adsorption-controlled process irrespective of pH. The evaluated adsorption equilibrium constant decreased from 3.21 × 105 to 1.61 × 105 mol L−1 for acidic to basic medium, which implies the strong affinity of the arsenic species in the acidic medium. Besides, the estimation of Gibbs free energy revealed that an acidic medium promotes arsenic oxidation on gold surface. In mechanistic aspect, the oxidation reaction adopts a stepwise pathway for acidic medium and a concerted pathway for neutral and basic medium. From the substantial kinetic evaluation, it is established that a conducive and compatible environment for the oxidation of arsenic was found in an acidic medium rather than a basic or neutral medium on gold surface. Besides, in sensitivity concern, neutral and highly acidic medium is quite favourable for the arsenite oxidation on gold surface