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采用溶胶-凝胶-超声工艺合成了一种由上转换发光材料Er~(3+)·NaYF_4复合TiO_2的光催化剂。通过XRD、UVVis、SEM、TEM等手段,对复合光催化剂进行表征,研究了该催化剂在可见光下,对亚甲基蓝光的催化降解性能。实验结果表明,溶胶-凝胶-超声法使Er~(3+)·NaYF_4以六方相形式与锐钛矿型TiO_2复合,且复合均匀性能良好;由于Er~(3+)·NaYF_4的复合,使TiO_2锐钛矿型晶格参数改变,复合催化剂可见光区产生明显吸收;25%,~30%,Er~(3+)·NaYF_4复合TiO_2的催化剂降解亚甲基蓝效果最佳,总脱色率达94%,以上,可见光降解率是TiO_2可见光降解率的3.6倍。因此,利用Er~(3+)·Na YF4上转换发光材料对TiO_2复合,可以使其吸光范围拓宽至可见光区,而且显著提升TiO_2光催化性能。
A kind of photocatalyst composed of upconversion luminescent material Er ~ (3+) · NaYF_4 composite TiO_2 was synthesized by sol-gel-ultrasonic technique. The composite photocatalysts were characterized by XRD, UVVis, SEM and TEM. The photocatalytic degradation of methylene blue under visible light was studied. The experimental results showed that Er 3+ NaYF 4 complexed with anatase TiO 2 in the form of hexagonal phase with good homogeneity was obtained by sol-gel-ultrasonic method. Due to the complexation of Er 3+ NaYF 4, The parameters of TiO2 anatase crystal lattice changed obviously and the visible light region of composite catalyst had obvious absorption. The best degradation rate of methylene blue was 25%, ~ 30%, Er ~ (3+) · NaYF_4 composite TiO 2, the total decolorization rate reached 94% , Above, visible light degradation rate is 3.6 times the visible light degradation rate of TiO_2. Therefore, the use of Er ~ (3+) · Na YF4 upconversion luminescent material on TiO 2 composite, can make its light absorption range broadening to the visible region, but also significantly enhance the TiO 2 photocatalytic performance.