Low temperature gel-combustion synthesis of porous nanostructure LaFeO3 with enhanced visible-light photocatalytic activity in reduction of Cr(VI)
Low temperature gel-combustion synthesis of porous nanostructure LaFeO3 with enhanced visible-light photocatalytic activity in reduction of Cr(VI)
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DOI：
10.1016/j.matlet.2017.03.133
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发表时间：
2017-06
影响因子：
3
通讯作者：
Xicai Hao;Yongcai Zhang
中科院分区：
文献类型：
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作者：
Xicai Hao;Yongcai Zhang
采用简单的凝胶燃烧法在200-400 °C的煅烧温度下合成了LaFeO 3。X射线衍射表征表明，在200-400 °C合成的产物均为纯钙钛矿相LaFeO 3。扫描电子显微镜图像显示，在200 °C下合成的LaFeO 3具有多孔纳米结构，但在400 °C下变成固体纳米结构。氮吸附测试结果表明，LaFeO 3的比表面积随焙烧温度的降低而增大。紫外-可见漫反射光谱表明，200 °C合成的LaFeO 3对可见光有最强的吸收。光催化实验表明，在可见光（波长大于420 nm）照射下，随着焙烧温度的降低，LaFeO 3对水溶液中Cr（VI）的光催化还原活性明显增强。本研究丰富了多孔纳米结构LaFeO 3的制备及其光吸收性能的研究，为LaFeO 3纳米材料在处理高毒性难降解Cr（VI）废水中的应用奠定了基础。
LaFeO3was synthesized via a simple gel-combustion method at the calcination temperatures of 200–400 °C. The X-ray diffraction characterization indicated that the products synthesized at 200–400 °C were all pure perovskite phase LaFeO3. The scanning electron microscopy images revealed that the LaFeO3synthesized at 200 °C had a porous nanostructure, but became a solid nanostructure at 400 °C. The nitrogen adsorption measurements suggested that the specific surface area of LaFeO3increased with the lowering of the calcination temperature. The UV–vis diffuse reflection spectra showed that the LaFeO3synthesized at 200 °C exhibited the strongest absorption of visible-light. The photocatalytic experiments demonstrated that as the calcination temperature was lowered, the resultant LaFeO3exhibited obviously enhanced photocatalytic activity in reduction of Cr(VI) in aqueous solution under visible-light (wavelength longer than 420 nm) irradiation. This work can enrich our knowledge on the synthesis and photoabsorption properties of porous nanostructure LaFeO3, and contribute to the application of LaFeO3nanomaterials in treating the wastewaters contaminated by highly toxic and intractable Cr(VI).