共查询到19条相似文献,搜索用时 51 毫秒
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将105 keV的Ti离子注入到SiO_2玻璃至1×10~(17)、2×10~(17) cm~(-2),并在氧气气氛下进行热处理,借助紫外可见分光光度计、掠入射X射线衍射光谱仪、透射电子显微镜、原子力显微镜等多种测试仪器,详细研究了Ti O2纳米颗粒的形成、结构、分布及其光吸收和催化性能。研究结果表明,高注量Ti离子注入结合氧气气氛热处理可以在SiO_2基底中形成TiO_2纳米颗粒,并以金红石相为主。合成的TiO_2纳米颗粒的形貌明显依赖于离子的注量,随离子注量增加,形状不规则且分散排列的TiO_2纳米颗粒会转变成尺寸较为均匀、分布致密的纳米颗粒,进而形成了TiO_2类颗粒膜结构。另外,光催化降解实验结果表明,合成的纳米颗粒对罗丹明B溶液具有一定的降解作用。 相似文献
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采用V 注入方法制备了能够吸收可见光的TiO2薄膜.紫外-可见光谱表明,随着V 注入量的增加,TiO2薄膜的光学带隙宽度减小.对注入后的TiO2薄膜退火可进一步减小光学带隙宽度.荧光光谱和可见光光催化实验表明,V 注入量为1×1016 /cm-2时,TiO2薄膜有最佳可见光光催化降解能力. 相似文献
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用电子束辐照浸泡在浓度分别为1×10-5、1×10-4、1×10-3、1×10-2和1×10-1mol/L的PdCl2溶液中的TiO2薄膜,在TiO2薄膜表面形成Pd纳米颗粒.通过X射线衍射(X-ray diffractometry,XRD)、场发射扫描电镜(Field emission scanning electron microscope,FESEM)、X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)和紫外可见(Ultraviolet visible,UV-Vis)吸收光谱对辐照后的Pd/TiO2薄膜进行表征.分析表明,TiO2薄膜表面上沉积了直径20-50 nm的颗粒,为面心立方结晶的金属Pd;Pd/TiO2薄膜的UV-Vis光谱吸收边向可见光方向发生了偏移.用甲基橙作为光催化降解反应物,研究了Pd/TiO2薄膜分别在紫外光、可见光作用下的光催化降解效率.结果表明,Pd/TiO2薄膜的光催化能力显著地提高,在紫外光、可见光作用下的光催化效率分别提高了2.25倍和3.4倍. 相似文献
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Cu离子和Al离子注入M2钢表面改性研究 总被引:9,自引:0,他引:9
报道了M2型高速工具钢在Cu,Al离子注入后表面硬度及抗磨损性的变化。对注入样品进行了显微硬度及抗磨损性的测量和XRD与RBS分析,观察了表面强化与离子注入条件之间的关系。结果显示,注入样品与未注入样品相比,表面硬度及抗磨损性均有显著提高。分析结果表明,Cu,Al离子注入后样品中产生了不同的相,它们对表面强化所起的作用不同。 相似文献
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低能离子注入介导Vc前体(2-KLG)产生菌DNA的转导 总被引:9,自引:0,他引:9
对低能离子注入2-酮基-L-古龙酸(2-KLG)生产菌的生物学效应和注入离子对DNA的损伤效应进行了初步研究。并以离子注入为介导将外源DNA转入2-KLG产生菌中,最终得到两株DNA重组菌。由此建立起离子注入介导微生物外源DNA转导的研究体系,为微生物转基因工程提供了一条新的途径。 相似文献
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用EXAFS方法研究了重金属Zn(Ⅱ)在δ-MnO2上吸附的微观结构及吸附机制。在pH5.50,0.1M硝酸钠介质中,吸附-解吸实验表明Zn(Ⅱ)在δ-MnO2上的吸附可逆性很高.EXAFS结果表明,δ-MnO2表面上吸附态Zn2 以六配位的水合离子八面体形式存在。八面体的水合Zn^2 离子与δ-MnO2的结构单元MnO6八面体通过共用O原子结合,形成角-角结合的弱吸附.Zn-O平均原子间距为2.071A,Zn-Mn平均原子间距为3.528A。同一条等温线上随着吸附量增加,角-角结合的弱吸附形式基本上没有变化。Zn(Ⅱ)在δ-MnO2上较高的吸附可逆性是由于吸附态Zn(Ⅱ)与δ-MnO2以弱吸附的角-角形式结合所导致的。 相似文献
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《核技术(英文版)》2015,(3)
TiO2 nanofilms on surface of fused silica were fabricated by Ti ion implantation and subsequent thermal annealing in oxygen ambience. The silica glasses were implanted by 20 k V Ti ions to 1.5 × 1017ions/cm2 on an implanter of metal vapor vacuum arc(MEVVA) ion source. Effects of annealing parameters on formation,growth and phase transformation of the TiO2 nanofilms were studied in detail. Optical absorption spectroscopy,Raman scattering spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy measurements were done to figure out formation mechanism of the TiO2 nanofilms.The formation of TiO2 nanofilms was due to out-diffusion of the implanted Ti ions to the substrate surface,where they were oxidized into TiO2 nanoparticles. Formation, phase, and thickness of the TiO2 nanofilms can be well tailored by controlling annealing parameters. 相似文献
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Ruiting Zheng Yong Zhao Kimberlee Collins 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(6):568-572
Polished Si substrates are sputtered by He+ ions, and carbon nanotube arrays are prepared on the Fe-coated substrates by heat chemical vapor deposition from acetylene. Scanning electron microscopy and atomic force microscopy are employed to examine the morphologies of sputtered substrates, catalyst and carbon nanotube arrays. It is found that ion sputtering is effective in increasing the roughness of Si substrates, and helpful in obtaining higher density Fe catalyst particles and better-aligned carbon nanotube arrays. 相似文献
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高度定向的碳纳米管阵列的制备 总被引:1,自引:0,他引:1
使用99.99%的铝片.在草酸溶液中,通过基于自组织基础上的二次氧化法制备了孔高度有序、六角排列的氧化铝模板,在微米尺寸区域内获得了高度平行的氧化铝纳米孔阵列。利用化学气相沉积技术(CVD),在没有任何过渡金属催化剂的情况下,利用多孔氧化铝模板本身的催化作用,在氧化铝模板孔内成功制备了高度有序的平行碳纳米管阵列,这种碳纳米管阵列可以作为研究离子束沟道传输特性的较理想材料。利用扫描电子显微镜(SEM)和电子背散射衍射(EBSD)等测试手段对铝片、氧化铝模板和碳纳米管的结构进行了表征。讨论了氧化铝模板的形成机制和基于氧化铝模板生长高度定向碳纳米管的条件。 相似文献
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LIU Xiuhua XU Yunshu ZHONG Zhijing FU Yibei DENG Yi 《核技术(英文版)》2007,18(1):59-64
Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn (11). When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight. 相似文献
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S. Okuji H. Boldyryeva Y. Takeda N. Kishimoto 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(8-9):1557-1560
Surface modification of polymers using radiation effects has been studied in a variety of fields, such as gas barrier or biochemical applications. However, the mechanism of improvement or degradation of polymers induced by radiation has not been well understood. In this study, poly(vinylidene difluoride) (PVDF) of crystalline phase of II (alpha form) was modified by plasma-based ion implantation (PBII) to control its adsorption properties for protein. Helium ions with applied bias voltages ranging from ?1 to ?20 kV were irradiated to the PVDF substrate for one minute and protein adsorption properties on the modified PVDF substrates was evaluated by the Western blotting method. As a result, adsorption of PVDF decreased with increasing the applied bias voltage, whereas the modification with only plasma treatment did not cause a significant change in adsorption properties for protein. The PBII-induced decrease in adsorption can be used for monitoring or patterning the protein. In order to study the mechanism, chemical and physical properties of the modified surfaces were analyzed with X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) in attenuated total reflection (ATR) mode. Contact angles on the modified surfaces were also measured and surface free energies were calculated by Owens–Wendt–Rabel–Kaeble method. The surface morphology observed AFM and SEM did not show a significant change after the modification but the concentration of fluorine decreased and the surface energy on the surface increased after the modification. The influential factors in adsorption properties of the modified PVDF for protein are discussed. 相似文献
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Shirong Zhao Hongjian Li Qingyao He 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(9):1435-1439
The electrical and optical characteristics of Zn+ ion-implanted Ni/Au ohmic contacts to p-GaN were investigated. After the preparation of Ni/Au electrode on the surface of p-GaN, the metal/p-GaN contact interface was doped by 35 keV Zn+ implantation with fluences of 5 × 1015-5 × 1016 cm−2. Subsequent rapid thermal annealing of the implanted samples were carried in air at 200-400 °C for 5 min. Obvious improvements of the electrode contact characteristics were observed, i.e. the decrease of specific contact resistance and the increase of light transmittance. The lowest specific contact resistance of 5.46 × 10−5 Ω cm2 was achieved by 1 × 1016 cm−2 Zn+ implantation. The transmission enhancement of the electrodes was found as the annealing temperature rises. Together with the morphology and structure analyses of the contacts by scanning and transmission electron microscope, the corresponding mechanism for such an improvement was discussed. 相似文献
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J.X. Xu X.H. Xiao F. Ren C.Z. Jiang 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(17-18):2702-2705
(0 0 0 1) α-Al2O3 single crystals (sapphire) were implanted with Zn ions of 60 keV at a fluence of 1 × 1017 ions/cm2. Transmission electron microscopy and optical absorption spectroscopy studies show the formation of ZnO nanoparticles in the sapphire substrate after the implanted sample was annealed at 700 °C in oxygen ambient. The photoluminescence spectrum of the annealed sample indicates the formation of ZnO nanoparticles with perfect lattice structure. The selected-area electron diffraction pattern proves that the ZnO nanoparticles have the (0 0 0 2) orientation which follows the orientation of Al2O3 substrate. The result shows that the crystallographic orientation of nanoparticles obtained through ion implantation is defined by the substrate. 相似文献
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离子注入植物种子的生物效应研究 总被引:21,自引:0,他引:21
用35-180keV离子束对玉米、水稻、小麦、黑麦等材料种子进行了氮或磷离子注入。结果发现,在被处理的当代种子中,发芽率,生长速度,植物株型等方面均出现了变异;对染色体行为的观察发现有丝分裂基本正常,减数分裂出现异常,对注入离子在种子内的分布进行了RBS测量,并以TRIM程序进行理论估算。对离子束作为诱变源的前景及机理进行了讨论。 相似文献