共查询到20条相似文献,搜索用时 66 毫秒
1.
可见光化的半导体光催化剂 总被引:1,自引:0,他引:1
光解水制氢能否实用化取决于太阳光的有效利用率, 研究开发可见光化的光催化剂成为当前光催化剂研究中的重要课题.本文介绍了利用 光解水制氢的反应机理,综述了近年来半导体光催化剂在利用可见光方面的研究进展,重点描述了这些光催化剂的结构,并对该领域今后的研究方向进行了展望. 相似文献
2.
近年来,铋系半导体材料因其在可见光辐照下对难降解有机物具有良好的催化作用而成为新型光催化材料的研究热点之一。本文综述了国内外铋系光催化剂的研究动态和主要成果。铋系光催化剂在可见光范围内有明显的吸收,具有较好的光催化活性。此外,大多数铋系光催化剂在反应过程中具有较高的稳定性。通过改进制备方法、掺杂负载、构建异质结等技术,可以有效提高铋系半导体材料的可见光吸收性能或抑制光生电子和空穴的复合,从而进一步提高其光催化性能。尽管铋系光催化剂由于其导带位置比氢的氧化还原电位低,但是通过设计合成新的能带结构可使其满足氧化和还原水的能带要求,从而实现铋系光催化剂在光解水制氢中的应用。最后,对铋系光催化剂未来的发展趋势进行了展望,并强调针对特殊用途和结合量化计算方法对开发新型铋系光催化剂的重要性。 相似文献
3.
4.
5.
6.
碳纳米管/半导体复合材料光催化研究进展 总被引:1,自引:0,他引:1
碳纳米管具有良好的机械性能和导电性、高化学稳定性、大表面积以及独特的一维结构,与半导体光催化剂结合能够增强催化剂的吸附能力、提高光催化效率、扩展光响应范围,而且有利于回收催化剂,极大地提高了半导体光催化剂的综合性能。本文首先分析了半导体光催化剂和碳纳米管的特点,总结了碳纳米管增强半导体光催化的机理,然后分别从复合材料制备方法、复合半导体种类和典型的应用三个不同角度,归纳总结了近年来碳纳米管/半导体复合材料光催化的研究进展,最后对其发展趋势作了展望。 相似文献
7.
铋系光催化剂具有良好的光催化性能,由于其Bi6s和O2p的轨道杂化,提高了价带的位置,从而减小了禁带宽度,使得铋系光催化剂在可见光范围内具有明显的吸收,已成为近年来光催化领域研究的热点。铋系光催化剂在可见光区的光催化活性虽然比传统的TiO2有明显的提高,但其量子效率不高,光生电子-空穴容易结合,对可见光的吸收有限等问题,使其离实际应用仍存在较大的距离。因此,必须采取合适的措施来提高铋系催化剂的光生载流子速率,抑制光生电子-空穴复合,增强对可见光的吸收。本文主要综述了近年来在铋系半导体光催化剂光催化性能调控方面的最新研究进展,重点就铋系半导体光催化剂的形貌控制、特殊晶面暴露、贵金属沉积、离子掺杂、非金属掺杂、半导体复合等方面进行分析和总结,并对铋系半导体光催化剂的发展方向进行展望。 相似文献
8.
通过溶剂热法制备了一种可磁回收CoFe2O4/RGO/BiOBr(CRB)三元复合光催化剂。利用TEM、XRD表征了该光催化剂的微观形貌和晶体结构。在可见光驱动下降解亚甲基蓝(MB)和诺氟沙星(NFX),探讨了光催化剂的光催化活性与稳定性,结果表明,制备得到的CRB复合光催化剂具有最佳的光催化性能,对MB(20 mg/L)的降解率在30 min能达到82.2%,光照60 min能降解81.7%的NFX(5 mg/L)。利用外加磁场将CRB复合光催化剂分离后进行了五次循环实验,该复合光催化剂对MB和NFX的降解率仍能分别达到80.2%和78.8%。结合UV-vis DRS、PL和EIS,研究了其光催化性能变化的原因。最后基于能带结构理论公式,推导出了磁性CRB体系的光催化降解机理。
相似文献
9.
10.
半导体复合TiO2纳米光催化剂 总被引:12,自引:0,他引:12
对近年来利用半导体复合TiO2纳米光催化剂进行了介绍。总结了复合TiO2纳米光催化剂的制备、复合物的种类、光催化机理以及影响半导体复合TiO2光催化性能的因素。 相似文献
11.
A. L. Stroyuk V. V. Shvalagin A. E. Raevskaya A. I. Kryukov S. Ya. Kuchmii 《Theoretical and Experimental Chemistry》2008,44(4):205-231
Existing data on photochemical and photocatalytic approaches to the formation of semiconducting nanoparticles and also binary
semiconducting nanostructures and nanocomposites of semiconductors with metals and polymers are reviewed. The nature of the
effect of irradiation on the synthesis and properties of the obtained nanostructures and the possibility of photocatalytic
control of the structural and spectral parameters of nanostructural semiconducting systems are examined.
__________
Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 44, No. 4, pp. 199–220, July–August, 2008. 相似文献
12.
Three fluorinated 1,8-napthalimides were synthesized from acenaphthene.Their structures were characterized by NMR and EI-MS analyses.The structures of compounds 1b and 1c were also confirmed by X-ray diffraction analysis,which showed that they possessed different packing models.Their optoelectronic properties were investigated.The results indicated that all of the naphthalimides possess good solubility and low LUMO energy level,which make them good solution processing candidates in n-type semiconductor. 相似文献
13.
Surface excitation parameter for 12 semiconductors and determination of a general predictive formula
The surface excitation parameter (SEP) is theoretically calculated for 12 semiconductors (GaN, GaP, GaSb, GaAs, InSb, InAs, InP, SiC, ZnSe, ZnS, Si and Ge) and for Ni (which is usually used as a reference in experiments) for electron energies between 300 eV and 3400 eV, and for angles between 0° and 70° to the surface normal. We use our previous definition of SEP, as the change in excitation probability, for an electron, caused by the presence of the surface in comparison with an electron moving the same distance in an infinite medium. The calculations are performed within the dielectric response theory by means of the QUEELS‐ε(k, ω)‐REELS software determining the energy‐differential inelastic electron scattering cross‐sections for reflection‐electron‐energy‐loss spectroscopy (REELS), and for which the only input is the dielectric function of the medium. By fitting to these SEP values as well as our previous ones, i.e. from 27 materials, including metals, oxides, polymers and semiconductors, we also establish a simple equation depending on the generalized plasmon energy and the energy band gap of the material which allows to estimate the SEP when the dielectric function is not available. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
15.
以有机溶剂热生长技术(solvothermaltechnique)制备了半导体硫族化合物(CdS、ZnS、MoS2)等纳米颗粒,采用XRD、TEM等技术对其结构进行表征.以ITO导电玻璃以及导电聚合物(PANI、PPY)膜为基底,将纳米颗粒涂布其上并以PL法研究其光学特性,实验结果表明:经修饰后,材料的荧光发射位置发生显著的变化. 相似文献
16.
Dimitra Papadimitriou Efthymios Liarokapis Wolfgang Richter 《Mikrochimica acta》2001,136(3-4):165-169
Strain effects on semiconductor layers were studied by means of optical spectroscopic techniques with a device developed
especially for the study of layered structures and microstructures. Raman, modulated photoreflectance and reflectance anisotropy
spectroscopy (RAS) were applied. Measurements were performed on elemental semiconductors (Si), semiconductor alloys (Si–Ge)
and III–V semiconductor compounds (GaAs). By application of RAS, strains lower than 10−4 could be resolved, which is at least one order of magnitude lower than those observable with Raman and modulated reflectance
techniques. The RAS spectra of layers strained along either the [010] or [011] direction showed a derivative-like structure
at E1-gap energies, which increased linearly and very quickly with increasing strain. The dependence of this spectral feature on
applied strain was used to evaluate strain-dependent effects. This behaviour strongly suggests that RAS can be applied for
the optical characterisation of strain in semiconductor microstructures and devices, with a higher efficiency and accuracy
than that achieved by previously established optical methods such as Raman and modulation spectroscopy. In addition, the compactness
and ease of operation of the instrumentation of RAS provides considerable potential for in situ monitoring/control of semiconductor fabrication conditions. 相似文献
17.
钙钛矿型复合氧化物光催化研究进展 总被引:9,自引:0,他引:9
扼要叙述了钙钛矿型复合氧化物(ABO3)作为光催化剂的研究进展。包括结构,机理,制备,改性和研究现状。强调了结构与性能之间的关系并对其研究方向提出了自己的见解。 相似文献
18.
The unsymmetrical disubstituted acetylene, iodocyanoacetylene (ICA), can be polymerized at 140°C in the solid state in high yield. The resulting polymer, polyiodocyanoacetylene (PICA), is a black lustrous stripe having the structure of . If the polymerization temperature is raised above 160°C, part of the iodine will split off from the polymer. However, at higher temperatures, the cyclization reaction occurs and the ladder polymer is formed. The conductivities of the pristine-PICA and its ladder polymers are all in the semiconductor region. 相似文献
19.
抗坏血酸为还原剂制备Se纳米线(英) 总被引:2,自引:0,他引:2
0IntroductionOne鄄dimensionalnanostructuressuchasnanowires,nanorods,ornanotubeshavebeenthesub鄄jectofintensiveresearchduetotheirpotentialuseasactivecomponentsorinterconnectsinfabricatingnanoscaleelectronicorelectromechanicaldevices[1].Theyalsorepresentane… 相似文献
20.
本文综述了半导体氧化物光催化裂解水制氢的反应机理,以及近年来半导体光催化裂解水制氢的研究进展。讨论了各种因素对材料光催化性能的影响以及改性方法,并对今后的研究方向提出了一些建议。 相似文献