Photocatalytic performance of TiO_2 nanocrystals with/without oxygen defects
无缺陷和氧缺陷二氧化钛的光催化活性
查看参考文献65篇
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文摘
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To investigate the role of oxygen defects on the photocatalytic activity of TiO_2,the TiO_2 nanocrystals with/without oxygen defects are successfully synthesized by the hydrothermal and sol-gel methods,respectively.The as-prepared TiO_2 nanocrystals with defects are light blue and the absorption edge of light is towards the visible light region (~420 nm).Raman and X-ray photoelectron spectroscopy (XPS) measurements all confirm that the concentration of oxygen vacancies in the TiO_2 synthesized by the sol-gel method is less than that synthesized through the hydrothermal route.The introduction of oxygen defects contributes to a new state in the band gap that narrows the band gap,which is the reason for the extension of light absorption into the visible light region.The photocurrent results confirm that this band-gap narrowing enhances the photocurrent response under simulated solar light irradiation.The TiO_2 with oxygen defects shows a higher photocatalytic activity for decomposition of a methylene blue solution compared with that of the perfect TiO_2 sample.The photocatalytic mechanism is discussed based on the density functional theory calculations and photoluminescence spectroscopy measurements. |
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其他语种文摘
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随着全球工业的发展,大量有机污染物排放到水中,已经威胁到人类健康.自1972年Fujishima和Honda发现TiO_2半导体材料可在光照下分解水以来,光催化技术作为一种新型污水处理方法引起广泛重视.近几十年来,光催化已被广泛研究,已成为水体净化领域最有前途的方法之一.TiO_2光催化剂由于具有无毒、耐腐蚀、高稳定和低成本等特点,在光催化领域受到广泛关注,是最具有开发前景的光催化材料之一.然而,TiO_2的禁带较宽,只能吸收仅占太阳光4%的紫外光部分,这严重限制了TiO_2光催化材料对太阳光的有效应用.最新研究结果表明,适量缺陷的存在可以拓展TiO_2对可见光的响应,从而通过提高其对太阳光的利用效率来有效提升TiO_2的光催化活性.因此,研究半导体缺陷与其光催化剂性能的关系,对于提升光催化污染物降解性能具有重要意义.本工作采用水热法和溶胶-凝胶法分别制备了具有氧缺陷的和无缺陷的TiO_2,用于研究氧缺陷对TiO_2光催化活性的影响.所制备的氧缺陷TiO_2纳米材料为浅蓝色,光的吸收波长向可见光区(~420 nm)拓展.拉曼光谱和X射线光电子能谱(XPS)测试均证明溶胶-凝胶法制备的TiO_2中氧空缺位的浓度低于水热合成TiO_2的氧空缺位浓度.光化学测试结果表明,氧缺陷TiO_2在模拟太阳光下的光电流响应增强,这是由于氧缺陷的引入导致能带隙内出现了新的电子态,使得禁带宽度变窄.在光降解亚甲基蓝(MB)的实验中,氧缺陷TiO_2材料表现出更高的光催化活性.根据密度泛函理论(DFT)计算和荧光光谱测试结果,讨论了氧缺陷TiO_2的光催化机理. |
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来源
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Chinese Journal of Catalysis
,2018,39(4):867-875 【核心库】
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DOI
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10.1016/S1872-2067(17)62999-1
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关键词
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TiO_2
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Defect
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Optical property
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Photocatalytic activity
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Density functional theory calculation
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地址
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1.
Institute of Catalysis for Energy and Environment,College of Chemistry and Chemical Engineering,Shenyang Normal University, Liaoning, Shenyang, 110034
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College of Chemistry,Nankai University, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Tianjin, 300071
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Department of Pharmacology,Shenyang Medical College, Liaoning, Shenyang, 110034
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College of Optoelectronic Engineering,Shenzhen University, Guangdong, Shenzhen, 518060
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语种
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英文 |
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文献类型
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研究性论文 |
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ISSN
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0253-9837 |
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学科
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化学 |
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基金
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the Doctoral Scientific Research Foundation of Liaoning Province
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the Scientific Research Project for University Students of Shenyang Medical College
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the Doctoral Scientific Research Foundation of Shenyang Medical College
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国家自然科学基金
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文献收藏号
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CSCD:6220175
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