Synthesis Of TiO₂ Based Nanomaterials And Its High-performance As Photocatalyst

In recent years,titanium dioxide?TiO₂?has been achieved continuous research attention for its chemical stability,low-cost,innocuous and high photocatalytic activity.However,wide band gap,low light utilization ratio and high electron-hole recombination rate greatly restrict its application in the photocatalytic oxidation field.Usually,the photocatalytic activity of TiO₂ can be improved via four methods of the doping method,noble metal deposition method,coupling of semiconductor and synthesis of materials with high anisotropy or high surface area.In this study,we focus on the synthesis of carbon doped TiO₂ nanoparticles with different ratios of mixed phases,the TiO₂ hollow spheres and C@TiO₂ core-shell structures with different sizes.Samples are analyzed by XRD,SEM,TEM,FTIR,XPS,PL and UV-vis absorption spectroscopy.The Rhodamine B?RhB?solution is used as the target degradation of photocatalytic and adsorption test characterization techniques.And the main results of this paper are listed as follow:?1?Choosing resorcinol,phloroglucinol,ethylene glycol and glycerol as carbon sources,respectively,C-doped TiO₂ nanoparticles are prepared via hydrothermal method,here glucose is first used to determine the optimal C-doping amount and reaction environment.The experimental results reveal that addition of a small amount of carbon can change the phase structure of the produced sample,the self-characteristic of carbon source influences the ratio of anatase and brookite in the mixed phase structures.The mixed crystal phases show a lower band gap energy and a less of the photogenerated electronic-hole recombination.Meanwhile,a rising amount of hydroxyls in carbon source and a high ratio of brookite phase in the mixed crystal phases are beneficial to the photocatalytic performance.?2?Carbon spheres are synthesized by direct hydrothermal method,and the particle size of samples is increased with the concentration of glucose solution and hydrothermal reaction time.The PEG-200 is innovatively used as dispersant in our experiment to synthesis monodisperse carbon spheres with particle sizes from 80 nm to 1.3 um through controlling its dosage.And the surface of product sample contains a large number of hydroxyl and carboxyl groups,which are useful to the further application as template.?3?The TiO₂ hollow spheres with different sizes and C@TiO₂ core-shell structures are synthesized by using the different prepared monodisperse carbon spheres as templates.The experimental results show that the TiO₂ hollow spheres have better photocatalytic performance than nanoparticles,and the photocatalytic properties of the TiO₂ hollow spheres with smaller particle size are better,which is derived from its larger specific surface area.And the C@TiO₂ core-shell structure has a strong adsorption capability of RhB solution in dark environment,which is rather different with reported photocatalytic degradation RhB for C@TiO₂.This can be attributed to the larger specific surface area of the sample and the interaction between the carbon core and the TiO₂ shell.