Synthesis Of Nanostructured TiO₂Templated By Cellulose And Their Application In Photocatatysis

Photocatalysis using sunlight has attracted considerable attention worldwide dueto the increasing demand for environmental remediation and energy conservation.Since1972, titanium dioxide because of its non-toxic and has good photocatalyticactivity and chemical stability, was extensive researched for a clean environment,hydrogen and solar cells. Unfortunately, the low electrical conversion efficiency facedserious challenges to its massive market prospects. Lots of effort was done to design aspecial structure of titanium dioxide in order to improve the photoelectric conversionefficiency, in which the synthesis of biological macromolecules using templates withhierarchically structure of titanium dioxide has broad prospects for the research.Cellulose is the most abundant biopolymer on earth, which is the linear polymercomposed of many β-D-glucose based on1â†'4glycoside bond. It surface contains alarge number of active hydroxyl group, make it with excellent template performance.Native cellulose consists of noncrystalline and crystalline domains, andnanocrystalline cellulose can be recovered from native cellulose using acid hydrolysis.Literatures show that cellulose can be acid hydrolyzed to water insoluble and solubleoligomers and to glucose under hydrothermal conditions. Therefore, this is theinspiration of exploration synthesis of hierarchically titanium dioxide under differentacidic conditions.In the first chapter, we’ll give an overview of the background of the fieldincluding the nature，the structure, the mechanism of photocatalytic degradation oforganic pollutants, the common methods to increase the photocatalytic efficiency oftitanium dioxide such as the doping, precious metal load, semiconductor composite,etc.,brief introduction of the nature of the microcrystalline cellulose (MCC) andnanocrystalline cellulose (NCC).In the second chapter of this thesis, we introduced the impact of adjusting theacidity, temperature and the amount of microcrystalline cellulose for the morphology of hierarchically nanostructured TiO2under hydrothermal conditions, Optimizedconditions, calcination and loads of gold nanoparticles, catalytic degradation ofmethyl orange contrast with P25under UV conditionsand. Show the impact of cokeand loading of noble metal for the photocatalytic properties of titanium dioxide.In the third chapter, we coat the tin dichloride and titania precursor on thesurface of nanocrystalline cellulose, prepared tin-doped titanium dioxide nanorodswith different calcined temperatures and load different concentrations of goldnanoparticles, enhance its ability to catalyze degradation of methyl orange under UV.