介质阻挡放电作用下快速制备缺陷纳米二氧化钛及其光催化性能研究

Rapid Preparation of Defective Nano Titanium Dioxide under Dielectric Barrier Discharge and its Photocatalytic Performance

缺陷二氧化钛(TiO_(2))已被广泛研究并应用于光催化降解有机污染物领域。为了快速制备光催化性能优异的缺陷TiO_(2)材料,本文以氮气(N_(2))和氢气(H_(2))为工作气体,采用介质阻挡放电(DBD)等离子体短时间(60 s)放电,成功制备了缺陷纳米TiO_(2)催化剂,在可见光照射下,80min即可达到94.73%的催化降解性能,光催化降解速率约为未经处理的纳米TiO_(2)的3.09倍。表征分析结果表明,经DBD等离子体处理后,TiO_(2)表面引入了表面氧空位和Ti^(3+)缺陷,形成了Ti^(3+)-Ov-Ti^(3+)缺陷能级,禁带宽度从3.2eV减小至2.97eV,增强了TiO_(2)材料在可见光区域的吸收光能力,同时,光生电子-空穴复合率受到抑制,TiO_(2)催化剂的光催化活性因此得到提升。

Defective titanium dioxide(TiO_(2))had been widely studied and applied in the field of photocatalytic degradation of organic pollutants.In order to quickly prepare defective TiO_(2)materials with excellent photocatalytic performance,applied nitrogen(N_(2))and hydrogen(H_(2))as working gases,the defective nano-TiO_(2)catalyst was successfully prepared in 60s by dielectric barrier discharge(DBD)plasma.Under visible light irradiation,its catalytic degradation performance reached 94.73%in 80min,and the photocatalytic degradation rate was about 3.09 times that of the untreated nano-TiO_(2).XRD,TEM,EPR,UV-vis,FT-IR and XPS were used to characterize the prepared catalyst.The results revealed that surface oxygen defects and Ti^(3+)were introduced on the surface of TiO_(2)to form Ti^(3+)−Ov−Ti^(3+)defect energy levels after DBD plasma treatment.The band-gap width was reduced from 3.2eV to 2.97eV,which enhanced the absorption capacity of TiO_(2)material in the visible light spectrum.Meanwhile,the recombination of photo-generated electron-holes was suppressed.Therefore,the catalytic activity of the TiO_(2)catalyst was improved by the DBD treatment.