Ho掺杂纳米TiO_2光催化性能研究

THE INVESTIGATION ON THE PHOTOCATALYTIC ACTIVITY OF Ho DOPED NANO TiO_2

以钛酸四正丁酯为原料,采用溶胶-凝胶法制备了纯的和Ho掺杂的TiO_2纳米粒子,对样品进行了TG- DTA、XRD和UV-Vis吸收光谱分析,并以甲基橙的光脱色反应考察了样品的光催化性能。发现Ho的掺杂抑制了TiO_2粒径的长大,细化了晶粒;Ho掺入到TiO_2的晶格中,引起了晶格的畸变和膨胀;Ho的掺杂使TiO_2的吸收带边发生微小的蓝移,且在450nm和540nm光区附近产生吸收;适量Ho的掺杂可提高TiO_2的光催化性能,紫外光照下,Ho的掺杂量为0.3%时,光催化性能最佳;可见光下(波长>420nm),Ho掺杂的TiO_2呈现光催化活性,210min内甲基橙的脱色率可达21.6%。

A series of Ho-doped and un-doped TiO2 nanoparticles were prepared by sol-gel method with tetra-n-butyl titanate as raw material. The samples were characterized with TG-DTA, X-ray diffraction （XRD）, and UV-Vis absorption spectra, and their photocatalytie activity were studied by photocatalytie depigmentation of methyl orange in water. The result showed that Ho doping not only restrained the growth of TiO2 grain size, but also led to the expansion and matrices dist＆tion of crystal lattices. A tiny blue-shift of the absorption profile and two absorption peaks around at 450 and 540 nm were found by the UV-Vis absorption spectra in Ho-doped samples. Appropriate content Ho doping improved the photocatalytie activity of TiO2. The photoeatalytie activity of 0.3 tool% Ho-doped TiO2 nanopartieles is optimal of all the prepared samples under UV irradiation. Ho-doped TiO2 took on excellent photoeatalytie activity under visible light （wavelength （λ） 〉 420 nm） irradiation and depigmentation ratio of methyl orange reached to 21.6% in 210min.