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以工业二氧化钛(TiO_2)、硝酸镧(LaN_3O_9·5H_2O)、三聚氰胺(C_3H_6N_6)为原料制备了La掺杂TiO_2/g-C_3N_4复合光催化剂.采用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、傅里叶变换红外(FT-IR)、紫外-可见吸收光谱(UV-Vis)、荧光光谱(PL)等表征方法对光催化剂结构进行分析,表明复合样品中La以La~(3+)形式存在于TiO_2晶体中,并形成TiO_2/g-C_3N_4异质结构,其禁带宽度减小、吸收带边红移,光催化效率有明显提高.以亚甲基蓝为目标污染物评价其光催化活性,镧掺杂量为4%(质量分数)、煅烧温度为520℃、煅烧时间为2 h时,复合样品光催化活性最佳,在12 LED灯下,180 min后对10 mg·L~(-1)亚甲基蓝溶液的去除率达97%.
The La-doped TiO 2 / g-C 3 N 4 composite photocatalyst was prepared from industrial TiO 2, LaN 3 O 9 · 5H 2 O and melamine C 3 H 6 N 6 by X-ray photoelectron spectroscopy (XPS) ), Transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), ultraviolet-visible absorption spectroscopy (UV-Vis), fluorescence spectroscopy (PL) and other characterization methods of the photocatalyst structure analysis showed that composite samples La exists in the form of La ~ (3+) in TiO_2 crystal and forms a heterogeneous structure of TiO_2 / g-C_3N_4, which decreases the forbidden band width and absorbs the red edge of the band edge and improves the photocatalytic efficiency. The photocatalytic activity of the composite was evaluated. The best photocatalytic activity was obtained when the content of lanthanum was 4% (mass fraction), the calcination temperature was 520 ℃ and the calcination time was 2 h. Under the condition of 12 LED lamp for 180 min The removal rate of 10 mg · L -1 methylene blue solution was 97%.