低温固相合成CaTiO_3纳米粉及其光催化处理水中Cr(Ⅵ)和硝基苯

Low Temperature Synthesis of CaTiO_3 Nanopowder and Its Photocatalytic Degradation of Cr(Ⅵ)-nitrobenzene

以等摩尔比Ca(NO_3)_2·4H_2O和P25 TiO_2在550-700℃下得到系列CaTiO_3纳米粉,通过XRD、SEM、UV-vis和光电流测试合成样品的组成、结构和光电性质。实验结果表明,550℃的固相反应所得含有CaCO_3杂质、呈现出不规则颗粒状的CaTiO_3,700℃时可以制得片状、纯正交相的CaTiO_3。在60W日用紫外灯照射下,CaTiO_3光催化处理水中Cr(VI)和硝基苯均表现出催化活性,且光生空穴的氧化能力高于光生电子的还原能力。光电流测试显示600℃下反应10h所得CaTiO_3的光生载流子的分离效率最高,也具有最高的光催化活性。

CaTiO3 nanopowders with good photocatalytic properties were prepared by low temperature solid phase method using equalmolar ratio of P25 TiO2 and Ca（NO3）2.4H20. X-ray diffraction and field emission scanning electron microscopy revealed the formation oforthorhombic phase CaTiO3 nanoparticles at 550-700 ℃. UV-vis absorption spectrum of the as-obtained CaTiO3 nanoparticles displayedultraviolet absorption. CaTiO3 used for photodegradation of aqueous Cr（VI） and nitrobenzene exhibited good photocatalytic activity under 60 wultraviolet lamp irradiation, and the oxidation ability of the photoproduction hole is higher than the reduction ability of the photoproductionelectron. CaTiO2-D has the highest photocatalytic activity on the basis of the highest separation rate of h＋-e- in photocurrent measurements.