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Abstract
The objective of this study is to evaluate the use of titanium dioxide nanoparticles which were prepared by novel sonochemical method as an ion exchange material for the removal of Sr from aqueous solution. The pH effect on the Sr2+ sorption was investigated. The data obtained have been correlated with Freundlich, Temkin and Dubinin–Radushkevich (D–R) isotherm models. Thermodynamic parameters fort he sorption system have been determined at four temperatures. Simple kinetic models have been applied to the rate and isotherm sorption data and the relevant kinetic parameters were determined from the graphical presentation of these models at 298°K. Results explained that the pseudo second-order sorption mechanism is predominant and the overall rate constant of sorption process appears to be controlled by chemical sorption process. The value of sorption energy E = 13 kJ/mol at 298°K and the value of Gibbs free energy ∆G° = 3,222 kJ/mol at 298°K prove that the sorption of strontium on titanium dioxide nanoparticles is an endothermic and non-spontaneous process.
effectively through simple process. Wherein, rutile nano-TiO 2 is a new and effective additive for the anti-ageing function [ 18 , 19 ]. But the effects of nano-TiO 2 on the curing properties of powder coating have not been revealed in articles. In
Introduction Titanium dioxide (TiO 2 ) is a popular material due to many applications arising from its high permittivity, refractive index, efficiency, low cost, chemical inertness, photocatalytic, photostability, and
catalytic properties of the TiO 2 -promoted vanadium oxide catalysts. The TiO 2 -anatase-based catalysts exhibit a higher activity in the oxidation of 3- and 4-methylpyridine [ 2 ]. It is established [ 3 ] that vanadium oxide VO 2 , which is formed during
Abstract
The surface acidic properties of sulfated vanadia–titania catalysts prepared by various methods were investigated by adsorption microcalorimetry, using ammonia as probe molecule. The acidic characteristics of the samples were shown to be strongly affected by the preparation method, calcination temperature, and sulfur content. The samples prepared by sol–gel and mechanical grinding exhibited higher acidity than co-precipitated samples. Moreover, increasing the calcination temperature of co-precipitated samples resulted in a decrease in surface area from 402 to 57 m2 g−1 and sulfur content from around 4 to 0.2 mass%, but up to a certain point generated a stronger acidity. The optimal calcination temperature appeared to be around 673 K.
Abstract
Advanced oxidation process is a technology used in detoxification of residual water containing organic pollutants in small and medium scales. Radiocatalysis is a process that combines photocatalysis and radiolysis. An important experimental parameter in radiocatalysis is the pH because it influences the electrochemical system by modifying the electric charge on the surface of materials. This effect was investigated in the radiocatalytic degradation of 4-chlorophenol using titanium, silicium, and aluminum oxides. It was found that the degradation of 4-chlorophenol is enhanced at pH between 3 and 7.
purification [ 1 , 2 ]. Among the photocatalysts, TiO 2 has gained much attention because of its superior photoreactivity, nontoxicity, long term stability, low cost and environmentally friendly features [ 3 , 4 ]. Nonetheless, due to the large band gap of
ethylene glycol (Mallinckrodt Baker). Colloidal dispersions containing 2 g of commercial TiO 2 nanoparticles in 50 mL of deionized water were prepared. The TiO 2 powder was dispersed in water using an ultra-sonic probe. An Al polymeric precursor water
of TiO 2 (3.2 eV for the anatase phase and 3.0 eV for the rutile phase) needs ultraviolet (UV) light for electron–hole separation, which is only 5 % of the natural solar light [ 5 ]. It is of great significance to develop photocatalysts that can be
vapor deposition CVD) strongly affect the structure and properties of STM. Titania-silicas can possess (a) complex structure both in the bulk and at the surface layer, as it is in the fumed ST or (b) separated phases of TiO 2 and SiO 2 with a clear
