Method for preparing high-valence-state manganese doped titanium dioxide

Abstract

The invention belongs to the technical field of doped titanium dioxide, and particularly discloses a method for preparing high-valence-state manganese doped titanium dioxide. The method comprises the following steps: by taking 0.2-0.6 g of TiB2 as a Ti source, adding 10-20 ml of concentrated hydrochloric acid and 30-50 ml of water to prepare hydrothermal reaction solution, and adding MnCl2 with an Mn / Ti atomic ratio of 2-10 percent to perform hydrothermal synthesis reaction at the temperature of 150-200 DEG C for 18-30 h to obtain settled clear solution; dropwise adding ammonia water into the settled clear solution, precipitating black floccules and floating in aqueous solution; dropwise adding the ammonia water until no precipitate is separated out, then repeatedly washing the precipitate until the precipitate becomes white, and performing suction filtration to obtain required precursor; fully drying the precursor and then heating and roasting in the air of 400-600 DEG C for 2-4 h. According to the method, the high-valence-state Mn doped titanium dioxide is obtained through a hydrothermal synthesis method and a chemical precipitation method; the light absorption band edge is obviously improved; controllable adjustment of the TiO2 light absorption band edge can be realized by controlling the proportion of the Mn<4+> / Mn<3+>.

Description

technical field [0001] The invention belongs to the technical field of doped titanium dioxide, and in particular relates to a method for preparing high-valent manganese-doped titanium dioxide. Background technique [0002] TiO 2 It has high oxidation activity, non-toxic and pollution-free, low cost, and stable chemical properties. It has high application value and prospects in the fields of photocatalysis, solar cells, sensors, and self-cleaning materials. Titanium dioxide photocatalytic degradation of organic pollutants is favored for its fast reaction speed, wide application range, complete deep oxidation, and full use of oxygen molecules in the air (in the water phase), especially when the concentration of organic pollutants is high. Or when it is difficult to degrade by other methods, this technology has more obvious advantages. Although the research on titanium dioxide photocatalytic technology has developed rapidly in the past 10 years, it is still in the stage of th...

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Problems solved by technology

Shanghai University Jia Liu et al have used this method to synthesize Sn-doped TiO 2 , the experimental process is simple and the cost is low, but it is not easy to form doping, or the performance of the result is usually not ideal

[0006] 2. Electrochemical method The method is simple and easy, but the disadvantage is that the voltage and current may be unstable, and only flake or other macro-shaped samples can be prepared. The prepared nanomaterials are not uniform, which affects the performance.

The above-mentioned various methods are not yet able to obtain Mn 4+ Doped TiO

Although some degree of red shift is achieved at the band edge of the absorption spectrum, it cannot reach the desired level

Although the range of the absorption spectrum can be further expanded by increasing the doping content, the main doping valence is still +3 or +2, and too much doping will cause denaturation of titanium oxide and lead to photogenerated current carrying. Reduced sub-lifespan and performance degradation and waste of resources

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