The Research Of Oxygen Vacancy Defects Nano Materials By Magnesiothermic Reduction

Nano materials with oxygen vacancy defects can show the grate property on electricity, magnetism, optics and wettability what the original material does not have. In such aspects, materials with oxygen vacancy defects also have a great advantage and potential application in the preparation of special electronic devices. The existing method of high temperature thermal reduction have difficulty in making high oxygen vacancy defects of nanometer materials. In these circumstances, We tried to make oxygen vacancy defects of nano materials by magnesiothermic reduction, using the methods of magnesium thermal reduction to make titanium oxide materials with oxygen vacancy and complex oxide such as strontium titanate materials etc. And the ability of photocatalysis degradation, and photocatalysis hydrogen production performance were studied.With the method of magnesium thermal reduction, Si and Si O2-x composite are obtained by the reduction of quartz fibers. We can get a different size and morphology of magnesium oxide whisker by controlling the temperature and the time of processes. The Mg O nanowhiskers were found to have crystallized structures with growth along the [100] direction. VS is considered to be the main mechanisms for the growth of the Mg O nanowhiskers. the catalyst and the pressure of carrier gas are considered as an influence to whisker growth while the partial pressure of the Mg vapor and the annealing time have played significant roles in determining the diameter and morphology of the nanowhisker. Their adsorption capacity can reduce the concentration of methylene blue solution.With the method of magnesium thermal reduction, titanium oxide materials with oxygen vacancy are obtained by the reduction in different temperature. The treatment bring a number of oxygen vacancy, expanded the light range of response, improved the photocatalytic efficiency. It can reduce initial concentration to 84% in 10 mg L-1methylene blue solution by 6 h in visible light, It can also get the rate of 627.55 umol/hg in hydrogen production with 100 w bulb simulated sunlight. And the oxygen vacancy defects can be considered as electron capturer, it can inhibit the recombination of electronic- hole, which may promoted the catalytic effect of the light reaction.With the method of magnesium thermal reduction, strontium titanate materials with oxygen vacancy are obtained by the reduction in different temperature. Results show that the crystalline structure of the products still maintain the perovskite. Under appropriate temperature magnesium can take the oxygen in strontium titanate materials to form oxygen vacancy by magnesiothermic reduction. We can control the oxygen vacancy defect content from 0.67% to 16.3% by simply controlling the temperature. the results show that different concentrations of oxygen vacancy defects can adjust the band gap of the material, inhibited the recombination of electronic-hole which may promoted the catalytic effect of in the visible light.