氮掺杂对二氧化钛光催化性能的影响

Influences of N-doping on photocatalytic property of titanium dioxide

采用溶胶-凝胶法,以硝酸铵为氮源,制备了氮掺杂二氧化钛薄膜,通过紫外可见吸收光谱(UV-VIS)、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)对氮掺杂二氧化钛进行表征,并以亚甲基蓝为降解模型,探讨了氮掺杂对二氧化钛光催化性能的影响。结果表明:当氮掺杂量为11%、煅烧温度为450℃时,其吸收光谱明显发生红移,样品的光催化活性最好。随着氮掺杂量的增加,薄膜的催化性能先增后减,主要原因是氮掺杂会影响晶相颗粒的生长和产生缺陷,薄膜表面更加粗糙,比表面积增大。煅烧温度对薄膜的催化性能的影响也呈现先增后减,因为煅烧温度会影响二氧化钛晶型的转变和结晶度的变化。

N-doped TiO2 thin films were prepared by sol-gel method with ammonium nitrate as N source.The products were characterized by UV-VIS, SEM, FTIR,and XRD.The influences of N-doping on photocatalytie property of titanium dioxide were discussed with the methylene blue as the degradation model.Results indicated that the redshift of the absorption band could be found obviously,and the photocatalytic activitiy was the best,when the N-doping dosage was 11% and the calcination temperature of thin films was 450℃ .With the increased amount of N doping,the photocatalytie activitiy of thin films increased firstly, and then decreased.The main reason was that the growth of crystalline phase, BET surface and flaw could be all affected effect after N-doping.As for the change of photocatalytic activitiy, because the crystal transition and crystallinity were affected by calcination temperature ,the effect of calcination temperature was the same as the amount of N-doping.