Solid-state Chemical Synthesis And Property Of Titanium Dioxide Photocatalytic Materials

Organic pollutants in water is an issue of common concern, a variety oftechniques have been developed to deal with the organic pollutants which is harmfulto both water and human’s healthy. The photocatalytic technology based onsemiconductor photocatalytic materials is widely used in a variety of degradation oforganic contaminants because it is low energy consumption, cheap, efficient and clean.Anatase titanium dioxide is the most widely used semiconductor photocatalyticmaterial, it has stable structures and properties, and efficient photocatalytic activity,which is the reason that titanium dioxide has a very widely applications in wastewatertreatment field. A simple and cheap method for the preparation of titanium dioxideand the systematic study of its effective degradation of organic pollutants is adirection of photocatalytic research field. The nanoparticles of titanium dioxide wereprepared by simple and convenient low-heating solid-state chemical reaction methods,their photocatalytic activities were measured by the degradation of methyl orange andmethylene blue under UV or simulated sunlight irradiation. And some modificationresearches used by silver, silver oxide, silver phosphate and graphite oxide weremade.Firstly, the titanium dioxide was obtained by the calcined of precursor which wassynthesized by low-temperature solid-state reaction. The photocatalytic activities weretested by the degradation of methyl orange and methylene blue. We discussed theinfluence of different reactants and reaction conditions on the composition,morphology and photocatalytic activities of products. The results showed that theas-prepared titanium dioxide to simulate pollutant molecules had excellentphotocatalytic activities under both UV and simulated sunlight irradiation. It wasfound that the rod-shaped titanium dioxide had the highest photocatalytic activitybecause of its agglomeration form of nanoparticles and lager specific surface area. Secondly, several photocatalytic composites of Ag/TiO2, Ag2O/TiO2, GO/TiO2were synthesized and characterized by XRD, EDS, TEM and FESEM. Thephotocatalytic activities of composites were higher than the pure titanium dioxidethrough the photocatalytic test. This is due to the addition compound can transfer thephotoelectrons effectively and avoid the combine of photoelectrons and vacancies.In addition, silver phosphate was synthesized by solid-state chemical reaction,and the photocatalytic activity was conducted under the simulated sunlight irradiation.We found the silver phosphate had an excellent photocatalytic activity, it coulddegraded the dye moleculars rapidly. Then the composite of silver phosphate andtitanium dioxide was synthesized by solid-state reaction. It was proved the surface ofsilver phosphate was coated by titanium dioxide nanoparticles. The photocatalyticactivities of composites were higher than the pure titanium dioxide and silverphosphate. Because of the existence of silver phosphate, it could transfer thephotoelectrons effectively, avoided the combine of photoelectrons and vacancies, andthe existence of titanium dioxide enhanced the stability of silver phosphate. Thesynergy effect leaded to the improvement of photocatalytic activity of materials.