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钙钛矿型复合氧化物Ca_2Fe_2O_5是一种新型的窄带隙半导体光催化材料。以Fe(NO_3)_3×9H_2O、Ca(NO_3)_2×4H_2O、聚乙烯醇和尿素为主要原料,采用微波协助溶胶-凝胶法成功制备了Ca_2Fe_2O_5。通过X射线衍射(XRD)、扫描电镜(SEM)、红外光谱(FT-IR)和漫反射谱(DRS)对Ca_2Fe_2O_5进行了表征,并研究了煅烧温度对Ca2Fe_2O_5光催化性能的影响。结果表明:700~1000℃煅烧都能得到Ca2Fe2O5;其中,800℃煅烧得到的Ca_2Fe_2O_5光催化性能最佳,其粒径为80~100nm,带隙吸收边波长为548nm,对应带隙宽度为2.3eV;在可见光条件下,800℃煅烧得到的纳米Ca2Fe2O5对模拟污水甲基橙表现出了优良的光催化降解性能。微波协助溶胶-凝胶法制备的Ca_2Fe_2O_5光催化活性明显优于单一溶胶-凝胶法制备的Ca2Fe2O5,是一种在污水处理方面具有应用前景的可见光催化剂。
Perovskite-type composite oxide Ca_2Fe_2O_5 is a new type of narrow-bandgap semiconductor photocatalyst. Ca 2 Fe 2 O 5 was successfully prepared by microwave assisted sol-gel method using Fe (NO_3) _3 × 9H_2O, Ca (NO_3) _2 × 4H_2O, polyvinyl alcohol and urea as the main raw materials. The properties of Ca 2 Fe 2 O 5 were characterized by XRD, SEM, FT-IR and DRS. The effects of calcination temperature on the photocatalytic activity of Ca 2 Fe 2 O 5 were also studied. The results show that Ca2Fe2O5 can be obtained by calcination at 700-1000 ℃. Among them, Ca2Fe2O5 calcined at 800 ℃ has the best photocatalytic activity, the particle size is 80-100nm, the bandgap absorption edge wavelength is 548nm, and the corresponding bandgap width is 2.3eV ; Under visible light conditions, calcined at 800 ℃ nano Ca2Fe2O5 simulated wastewater methyl orange showed excellent photocatalytic degradation. The photocatalytic activity of Ca_2Fe_2O_5 prepared by microwave assisted sol-gel method is obviously better than that of Ca_2Fe_2O_5 prepared by single sol-gel method. It is a kind of visible light photocatalyst with potential application in sewage treatment.