Preparation Of Modification Expanded Graphite And Its Catalytic Properties

Expanded graphite(EG) is a worm-like porous material which is produced by natural squama graphite. It has evolutive network-like pore structure, big specific surface area, and high surface-active, it's a kind of cheap environment-friendly liquid phase adsorption with high chemistry stability. TiO2 is a kind of new cheap and non-toxic photochemical catalysis material. The compounds which made by EG and TiO2 not only has the adsorption performance, moreover also has the photochemical catalysis performance, which provided a new idea and a new focus of study on environmental material.TiO2/EG and TiO2/Fe/EG were successfully prepared with a new method using exfoliated graphite as support tetrabutyl titanate as titanium source and Iron (III) chloride as Fe3+source. These compounds were used to the study of adsorption and photodegradation of phenol synthetic wastewater. The research including:3,Lower-sulfuric expandable graphite was prepared with chemistry oxidation, and the affecting factors on expandable volume of exfoliated graphite were studied.899 flake graphite as raw material, and use the four levels of five factors in orthogonal test to determine the optimum process conditions. TiO2 and TiO2/Fe sol was prepared with sol-gel process, and then the sol was deposited on EG surface u with two different methods, and made two kind of TiO2/EG. The expansion volumes of these adsorbents were contrasted by using graduated container method. The microstructure and phase of these absorbents were studied by using SEM and XRD.4,The adsorbability of phenol at different pH, at different times and for different temperatures was studied. The two kinds of TiO2/EG were used to treat phenol synthetic wastewater, and the adsorbability and photodegradation ability were contrasted and studied. The phenol removal effect of TiO2/EG was studied under different conditions, just like:degradation time, phenol initial concentration, the consumption of EG or TiO2/EG, TiO2 inserted amount, different illuminations, and so on. The phenol removal ability of TiO2/Fe/EG was studied, the research including:effects of Fe3+doped amount, the effect of H2O2 and aniline. The adsorption and photodegradation mechanism of TiO2/EG and TiO2/Fe/EG was elementary deduced.The results showed that:3,expanded graphite having an exfoliation volume of 250mL/g could be produced under the optimum conditions with the weight ratio of natural flake graphite:nitric acid:phosphoric acid:potassium permanganate being 1:1.65:1.92:0.18, reaction time of 40 min, reaction temperature of 60℃, and microwave expanded time of 20 second. The TiO2/EG which inserting TiO2 first has bigger expansion than the TiO2/EG which expand first, and the TiO2/EG which inserting TiO2 first can keep its appearance as worm-like. TiO2 load the expanded graphite has been formed, and was anatase TiO2. Due to the doping of smaller vanadium, it was not obvious in the map display.4,The best pH condition of EG adsorption of phenol is 7, low temperature is beneficial to the adsorption of phenol. The TiO2/EG which inserting TiO2 first have more strong capability of adsorption and degradation than the TiO2/EG which expand first. There is good degeneration effect to the phenol by using TiO2/Fe/EG under the ultraviolet ray. Fe3+-dope can made phenol be degeneration well under visible light. It is showed that doped amount is 5%, inserted amount is 35% made TiO2/Fe/EG have the best removal ability of phenol. When phenol concentration is 376.98mg/L时, TiO2/Fe/EG dosage is 3g/L, the removal quantity of phenol is 62.12mg/g. When H2O2 in the system, it can promote the degeneration of phenol. When aniline in the system, it can weaken the adsorption and the degeneration of phenol.In this paper, expanded graphite as a selection of Fe3+-doped titanium dioxide nano-catalyst carrier. Combined with the advantages of both, to play its synergy photocatalytic preparation of low cost materials, adsorption, and high catalytic activity. Can be used as a degradation of sound absorption properties of materials widely used in environmental protection.