HNO3-involved one-step low temperature solvothermal synthesis of N-doped TiO2 nanocrystals for efficient photocatalytic reduction of Cr(VI) in water
HNO3-involved one-step low temperature solvothermal synthesis of N-doped TiO2 nanocrystals for efficient photocatalytic reduction of Cr(VI) in water
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DOI：
10.1016/j.apcatb.2013.05.023
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发表时间：
2013-10
影响因子：
22.1
通讯作者：
Y. Zhang;Min Yang;Geshan Zhang;D. Dionysiou
中科院分区：
文献类型：
--
作者：
Y. Zhang;Min Yang;Geshan Zhang;D. Dionysiou
提出了一种以硝酸为氮源的低温（180 °C）溶剂热一步法合成N掺杂纳米TiO 2（记为TiO 2-HNO 3）的方法。采用X射线衍射、傅里叶变换红外光谱、X射线光电子能谱、透射电子显微镜、高分辨透射电子显微镜、N2吸附-脱附等温线和紫外-可见漫反射光谱等手段对TiO 2-HNO 3的结构、组成、BET比表面积和光学性能进行了表征。在紫外和可见光（λ> 420 nm）照射下，考察了TiO 2-HNO 3光催化还原水中Cr（VI）的性能，并与以NH3. H2O为氮源溶剂热合成的TiO 2-NH3. H2O和TiO 2 P25进行了比较。结果表明，在紫外光和可见光（λ> 420 nm）照射下，TiO 2-HNO 3对Cr（VI）水溶液的光催化还原活性明显高于TiO 2-NH3. H2O和TiO 2 P25，且TiO 2-HNO 3的用量和Cr（VI）水溶液的初始浓度对Cr（VI）水溶液的光催化还原效率有显著影响。此外，Cr（VI）在TiO 2-HNO 3光催化反应后被还原为Cr（III）。研究表明，硝酸是低温溶剂热法合成氮掺杂纳米TiO 2的理想氮源，其可作为可见光催化剂用于高效利用太阳能处理含Cr（VI）废水。
A one-step low temperature (180 °C) solvothermal route, which utilized HNO3as the nitrogen source, was proposed for the synthesis of nanocrystalline N-doped TiO2(denoted as TiO2-HNO3). The structure, composition, BET specific surface area and optical properties of TiO2-HNO3were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy, N2adsorption–desorption isotherms and UV–vis diffuse reflectance spectroscopy. The photocatalytic properties of TiO2-HNO3were tested for the reduction of Cr(VI) in water under both UV and visible light (λ> 420 nm) irradiation, and compared with those of TiO2-NH3·H2O (which was solvothermally synthesized using NH3·H2O as the nitrogen source) and TiO2P25. The photocatalytic results demonstrated that TiO2-HNO3possessed much higher photocatalytic activity than TiO2-NH3·H2O and TiO2P25 in the reduction of aqueous Cr(VI) under both UV and visible light (λ> 420 nm) irradiation, and the dosage of TiO2-HNO3and the initial concentration of Cr(VI) aqueous solution had significant effects on the efficiency of Cr(VI) reduction. Besides, Cr(VI) was reduced to Cr(III) after the TiO2-HNO3-mediated photocatalytic reactions. The present work suggests that HNO3is a promising nitrogen source for low temperature solvothermal synthesis of nanocrystalline N-doped TiO2, which can be applied as a visible light-activated photocatalyst in efficient utilization of solar energy for treating Cr(VI) wastewater.