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为拓展二氧化钛的光响应波长范围并提高其光催化活性,通常采用掺杂金属、金属氧化物或金属离子的方法。大量研究表明,掺杂金属、金属氧化物或金属离子往往以损失TiO2光催化剂在紫外光区的光催化活性为代价,而掺杂非金属离子不但能将TiO2的光响应波长拓展至可见光区域外,还能保持在紫外光区的光催化活性,在利用太阳光光催化方面展现出崭新的应用前景。本文综述了非金属氮、碳、硫、氟等掺杂改性二氧化钛光催化的最新进展。 相似文献
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为拓展二氧化钛的光响应波长范围并提高其光催化活性,通常采用掺杂金属、金属氧化物或金属离子的方法.大量研究表明,掺杂金属、金属氧化物或金属离子往往以损失TiO2光催化剂在紫外光区的光催化活性为代价,而掺杂非金属离子不但能将TiO2的光响应波长拓展至可见光区域外,还能保持在紫外光区的光催化活性,在利用太阳光光催化方面展现出崭新的应用前景.本文综述了非金属氮、碳、硫、氟等掺杂改性二氧化钛光催化的最新进展. 相似文献
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非金属改性可见光诱导的TiO2光催化 总被引:4,自引:0,他引:4
为拓展二氧化钛的光响应波长范围并提高其光催化活性,通常采用掺杂金属、金属氧化物或金属离子的方法。大量研究表明,掺杂金属、金属氧化物或金属离子往往以损失TiO2光催化剂在紫外光区的光催化活性为代价,而掺杂非金属离子不但能将TiO2的光响应波长拓展至可见光区域外,还能保持在紫外光区的光催化活性,在利用太阳光光催化方面展现出崭新的应用前景。本文综述了非金属氮、碳、硫、氟等掺杂改性二氧化钛光催化的最新进展。 相似文献
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TiO2因其毒性低、稳定性高、制备成本低廉而获得广泛应用,特别是作为光催化剂在降解环境污染物方面受到了广泛关注;然而,纯TiO2较大的光生载流子复合率和较宽的带隙限制了其应用.元素掺杂作为一种拓宽光催化剂光吸收能力的方法广泛应用于各种光催化剂的修饰改性,而两种具有光催化性能的TiO2相共存则能有效抑制光生载流子的复合,因此采取合适的方法有效利用这两种TiO2改性的方法制备得到更具实际应用潜质的光催化剂具有一定的可行性.本文通过简单的溶胶-凝胶过程向锐钛矿相与金红石相组成的混相TiO2中共掺杂碳和钇得到了一种活性较高的可见光响应光催化剂.采用粉末X射线衍射、拉曼光谱、X射线光电子能谱和透射电镜等表征手段研究了碳和钇掺杂对TiO2结构的影响,发现碳掺杂有利于金红石相的形成且材料具有更大的晶粒尺寸,钇掺杂则有利于锐钛矿相的形成且能细化材料的晶粒尺寸,提高材料的比表面积,导致材料更好的光催化活性.材料在30 W荧光灯光照条件下的光催化降解亚甲基蓝(MB)性能的研究显示,C-Y-TiO2样品具有比单掺杂和未掺杂样品更高的光催化活性,其顺序为C-Y-TiO2>Y-TiO2>C-TiO2>TiO2≈P25.此外,降解反应动力学研究表明C-Y-TiO2样品光降解MB的速率是未掺杂样品在相同条件下降解速率的3.5倍.不同钇掺杂含量样品的结构和光催化降解MB的研究结果表明,钇掺杂显著促进了锐钛矿相TiO2的形成.这说明钇可能仅掺杂进入锐钛矿相,因此合适的钇掺杂量才能有效形成最优化的光催化性能的混相TiO2.不同热处理温度下获得的样品的光降解MB特性也表明,一定的热处理温度有利于合适的锐钛矿相和金红石相的组成,从而有利于相间的协同效应.紫外-可见光谱和荧光光谱表征分析表明,碳和钇的掺杂都拓展了其吸收光谱到可见光区域,且抑制了光生电子和空穴对的复合,进而提高了材料的光催化活性.碳和钇共掺杂的混相TiO2具有较高可见光光催化活性的主要原因有两个方面:一是元素掺杂减小了TiO2的带隙使得材料具有可见光响应;二是金属和非金属元素在锐钛矿相与金红石相TiO2中不同的掺杂特性形成的协同效应,抑制了光生电子和空穴的复合. 相似文献
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综述了近年来国内外利用氮掺杂改性二氧化钛的光催化剂性能、提高可见光的利用效率的最新研究进展;分析和讨论了氮掺杂二氧化钛的制备方法、理论计算和结构模型、掺杂机理等;总结了氮掺杂改性二氧化钛存在的问题,同时讨论了今后的研究方向. 相似文献
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《物理化学学报》2020,(3)
自从Fujishima和Honda利用TiO_2光阳极和Pt电极成功实现太阳能光电化学分解水之后,光催化被认为是解决环境污染和能源短缺两大问题最有前景的方法之一,因为该技术可以有效的利用太阳能这种地球上最丰富的能源来驱动多种不同的催化反应实现能源生产和环境净化,比如:水分解、CO_2还原、有机污染物降解和有机合成等。除了金属氧化物、金属硫化物和金属氮氧化物等多类金属化合物半导体光催化剂,近几年,石墨相氮化碳(g-C_3N_4)因其原料来源广泛、无毒、稳定以及相对较窄的带隙(2.7 eV)而具备可见光响应等特点,在光催化领域获得了广泛的重视。然而,gC_3N_4对太阳光谱中可见光的吸收效率较低且光生电子和空穴复合严重,导致其光催化活性处于较低水平。至今,研究人员已经开发出多种提高g-C_3N_4光催化活性的方法,如元素掺杂、微纳结构和异质结构设计和助催化剂修饰等。元素掺杂被证明是调节g-C_3N_4独特电子结构和分子结构的有效方法,可以大幅扩展其光响应范围,并促进光生电荷分离。特别地是,非金属元素掺杂以提高g-C_3N_4的光催化活性已经得到很好的研究。通常用于掺杂g-C_3N_4的非金属元素是氧(O)、磷(P)、硫(S)、硼(B)、卤素(F、Cl、Br、I)和其他非金属元素(如碳(C)和氮(N)自掺杂),因为这些非金属元素有着易于获取的原材料并可以较为简单的引入g-C_3N_4骨架结构中。在这篇综述文章中,作者首先介绍了g-C_3N_4的结构和光学性质,接着简要介绍了光催化剂的g-C_3N_4的改性;然后详细回顾了非金属掺杂改善g-C_3N_4光催化活性的进展,同时总结了光催化机理以期更好地理解光催化的本质并指导新型g-C_3N_4光催化剂的开发。最后,对g-C_3N_4光催化剂的后续研究进行了展望。 相似文献
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S-, N- and C-doped titanium dioxide nanoparticles: Synthesis, characterization and redox charge transfer study 总被引:1,自引:0,他引:1
K. Madhusudan Reddy 《Journal of solid state chemistry》2005,178(11):3352-3358
Herein we report on the synthesis and characterization of TiO2 nanomaterials doped with anions like sulfur, carbon and nitrogen. Upon doping, the absorption extends well into the visible region. This shift in the absorption edge is accompanied by a concomitant narrowing of band gap. The resulting anion-doped TiO2 nanomaterials were characterized by XRD, XPS, elemental analysis, EDAX, TEM, UV-DRS, DC conductivity, AC impedance and cyclic voltammetric studies. XPS confirms the presence of the dopants and the elemental analysis determined the amount of dopants in TiO2. Electrochemical characterization was carried out by cyclic voltammetry at pHs 2, 6.5 and 10. As against the response of undoped TiO2, the doped samples show an active electrochemical response indicating an induced charge transfer across the titania/solution interface, thus forming two anodic peaks and a cathodic peak. This interesting and significant observation was understood in terms of band bending due to anion doping as well as to the pH changes in the experimental solutions. 相似文献
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Min Li Qun Zeng Huang Dong Fang Qiu Zhu Jin Jiao Zhao Hui Meng Heng Zhen Shi 《中国化学快报》2010,21(1):117-121
<正>Nitrogen-doped TiO_2 nanophotocatalysts were prepared,and characterized by XRD patterns and UV-vis spectroscopy.The results indicated that nitrogen was doped effectively and the shift of the absorption edge to a lower energy and a stronger absorption in the visible light region were observed.The calcinations temperature is a key factor to narrow the band gap of titania,and consequently affects the response to visible light of nitrogen-doped TiO_2 nanocrystals.This photocatalyst can effectively inhibit the growth of Helminthosporium maydis,whereas undoped TiO_2 nanocrystals cannot inhibit the growth of H.maydis under the same experimental conditions. 相似文献
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Preparation and characterization of nitrogen-doped TiO2 photocatalyst in different acid environments
Ye Cong Ling Xiao Jinlong Zhang Feng Chen Masakazu Anpo 《Research on Chemical Intermediates》2006,32(8):717-724
Nitrogen-doped TiO2 powders were successfully prepared by a wet method, i.e., a micro-emulsion-hydrothermal method, in different acid environments.
Several characterization techniques, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse
reflectance spectra, were combined to determine the crystal phase, concentration and chemical states of the nitrogen doped
in TiO2. The high photocatalytic activity of the nitrogen-doped TiO2 was evaluated through the decomposition of rhodanmine B under visible light irradiation. It was suggested that the doped
nitrogen formed oxynitride (NO) and produced impurity states at higher above the valence band of TiO2. Therefore, the nitrogen doping could enhance the response of photocatalyst to the visible light and improve the photocatalytic
activity because of the narrowing of band gap of TiO2. 相似文献
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The modification of titania by metal / non metal ion doping, coupling with narrow band gap sensitizer, surface flourination,
metal deposition, and together with recent ventures on application of {001} facets of anatase titania for visible light response
with enhanced charge carrier separation are briefly overviewed. 相似文献
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Nitrogen doped TiO2 represents one of the most promising material for photocatalitic degradation of environmental pollutants with visible light. However, at present, a great deal of activity is devoted to the anatase polymorph while few data about rutile are available. In the present paper we report an experimental characterization of N doped polycrystalline rutile TiO2 prepared via sol-gel synthesis. Nitrogen doping does not affect the valence band to conduction band separation but, generates intra band gap localized states which are responsible of the on set of visible light absorption. The intra band gap states correspond to a nitrogen containing defect similar but not coincident with that recently reported for N doped anatase. 相似文献
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N掺杂TiO_2光催化剂的微结构与吸光特性研究 总被引:1,自引:0,他引:1
以紫外可见漫反射光谱(UV-VIS-DRS)和X射线光电子能谱(XPS)分析和研究了四种方法制备的N掺杂TiO2光催化剂的结构,即水解法(N/TiO2-H)、氨热还原法(N/TiO2-A)、机械化学法(N/TiO2-M)和尿素热处理法(N/TiO2-T)等.结果表明,N/TiO2-H和N/TiO2-T两种催化剂在490 nm处有吸收带边,可见光激发途径是掺杂的N以填隙方式形成的杂质能级吸收电子发生的跃迁引起的;而N/TiO2-A和N/TiO2-M两种催化剂在整个可见光区域内具有可见光吸收,其对可见光的激发途径是掺杂N和氧空缺共同作用的结果.理论计算的N杂质能级位于价带上0.75 eV,与实验观察到的吸收带边结果十分吻合.XPS结果表明,几种催化剂的N1 s结合能位置都在399 eV附近,显示为填隙掺杂的N原子.填隙掺杂的N/TiO2,其Ti原子的2p结合能与未掺杂的TiO2相比增加了+0.3-+0.6 eV,而O1s电子的结合能增加了+0.2-+0.5eV,这是因为填隙的N原子夺取Ti和O的电子,Ti和O原子周围的电子密度降低了.电子能谱和吸光特性的研究都表明,掺杂的机理是在TiO2晶格内形成N原子的填隙. 相似文献
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Mohammad Hossein Habibi Reza Mokhtari 《Journal of Thermal Analysis and Calorimetry》2013,112(3):1179-1183
One of the classic methods to extend the spectral response of a wide band gap titania semiconductor to visible light is impurity doping. This study has studied undoped, S-doped, Nb-doped, and S, Nb co-doped titania nanopowders prepared by sol–gel. The relationship between the doping conditions and the thermal stability, phase composition, crystallinity, morphology of particles, and the influence of dopant in similar conditions was investigated. Also the relationship between the dopant and the properties of titania nanosized powders, such as thermal stability, phase composition, crystallinity, morphology and size of particles, was investigated. Thermogravimetry coupled with differential thermogravimetry, X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscope was used for the characterization of the materials. During heating of the air dried samples, their chemical degradation took place giving rise to anatase phase. 相似文献
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Homogenous Boron‐doping in Self‐sensitized Carbon Nitride for Enhanced Visible‐light Photocatalytic Activity 下载免费PDF全文
We report a solvothermal approach for the preparation of homogeneously B‐doped self‐sensitized carbon nitride (B‐SSCN) composed of a core of B‐doped carbon nitride microspheres and a covalently linked shell of s‐triazine oligomers. Compared to the undoped structure, the obtained B‐SSCN photocatalyst exhibits an enhanced visible‐light activity, excellent stability for photocatalytic hydrogen generation due to a reduced band‐gap, enhanced charge‐separation efficiency, and better surface reactivity of B‐SSCN. This work provides a new strategy to uniformly insert heteroatoms into the polymeric carbon nitride framework for the development of metal‐free photocatalysts towards efficient production of solar fuels. 相似文献
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Using industrial titanyl sulfate as a raw material, Fe‐doped sulfated titania (FST) photocatalysts were prepared by using the one‐step thermal hydrolysis method and characterized using XRD, SEM, TGA–DSC, FTIR, UV–Vis DRS and N2 adsorption–desorption techniques. The effects of calcining temperature on the structure of the titania were investigated. The photocatalytic activity of the FST was evaluated using the photodegradation of methylene blue and photooxidation of phenol in aqueous solutions under UV and visible light irradiation, respectively. The results evinced that Ti4+ is substituted by Fe3+ in titania lattice and forms impurity level within the band gap of titania, which consequently induces the visible light absorption and visible‐light‐driven photocatalytic activity. The synergistic effects of Fe‐doping and sulfation are beneficial to the efficient separation of the photogenerated carriers and also improve the quantum efficiency of photocatalysis. In addition, Brönsted acidity arisen from the strong inductive effect of sulfate is also conducive to enhancing the photocatalytic performance of FST. However, when the calcining temperature is higher than 800°C, sulfur species and surface hydroxyl groups decompose and desorb from FST and the specific surface area decreases sharply. Moreover, severe sintering and rutile phase formation occur simultaneously. All these are detrimental to photocatalytic activity of FST. 相似文献