共查询到18条相似文献,搜索用时 99 毫秒
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研究了大面积均匀平整的纳米颗粒银层电沉积的机理, 优化了制备工艺, 探索了其在表面增强拉曼光谱检测中的应用. 结果表明, 该纳米颗粒银层的电沉积随着电极电势的负移, 逐步由连续成核转向瞬时成核机理, 在电流密度为1.0 A/dm2, 阴阳极面积比为1∶10, 以及20~30 ℃条件下, 银层具有更强的表面增强效应. XRD测试表明, (111)晶面为银电沉积层的择优取向面; 扫描电子显微镜表征表明, 银的颗粒尺度为6~11 nm. 该电沉积层作为表面增强拉曼光谱的活性基底, 具有灵敏度高及检测限低的特点, 对罗丹明6G 分子的检测限低至1.0×10-12 mol/L, 同时在大范围内的拉曼增强效果均匀, 展现了良好的应用前景. 相似文献
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沉积电位对电沉积ZnS薄膜的影响 总被引:1,自引:0,他引:1
采用电沉积方法,在不同沉积电位条件下,在氧化锡铟(ITO)导电玻璃上沉积制备了ZnS薄膜,利用XRD、SEM和UV-VIS测试技术对在不同沉积电位所制备薄膜的晶相结构、表面微观形貌和光学性能进行了表征.研究结果表明:沉积电位在1.5 V—1.7 V范围内制备的ZnS薄膜呈非晶态,其可见光透过率从60 %降低到20 %,薄膜的光学带隙约为3.97 eV.在沉积电位为2.0 V条件下所沉积薄膜为ZnS结晶相和金属Zn混合相,薄膜透过率显著降低. 相似文献
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温度对ZnO薄膜电沉积的影响 总被引:1,自引:0,他引:1
通过0.1 mol·L-1 Zn(NO3)2体系在不同温度下的电势-pH图、组分的分布系数和ZnO/Zn(OH)2沉淀的溶解度热力学计算得出最佳电沉积实验条件及最终沉积产物. 随后用沉积过程的循环伏安曲线、电流密度-时间曲线、薄膜的X射线粉末衍射(XRD)、扫描电子显微镜(SEM)和热重-差热(TG-DSC)实验结果验证了热力学理论分析. 光学研究发现, ZnO薄膜在可见光区具有高透光度(>80%)和较为陡峭的吸收边缘. 提出硝酸锌水溶液中电沉积ZnO的反应机理. 相似文献
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电沉积条件对锌镀层织构的影响 总被引:14,自引:1,他引:14
采用XRD方法研究添加剂,络合剂,以及电流密度对锌酸盐镀锌层的织构和晶粒尺寸的影响,结果表明,添加剂AA-1的存在有利于(101)晶面取向;而DIE则使镀层转变为110择优;两种添加剂同时存在下,可在一定的电流密度范围内获得高择优取向的锌镀层,而当又有络合剂TEA和EDTA同时存在时,则可在更宽广的电流密度范围内制得日 粒细密、表面光亮、择优系数TC(110)在985以上的高择优取向锌沉积层。 相似文献
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水溶液中Ni-La-P合金的电沉积行为 总被引:13,自引:0,他引:13
为了开发含稀土的功能材料,我们研究了从水溶液中电沉积Ni-La-P合金工艺[1].刘淑兰等[2]报道了电沉积的Ni-La合金上的阴极析氢行为,但未见Ni-La合金电沉积行为的报道.本文采用动电位扫描法,研究了电沉积Ni-La-P合金过程中,镀液中的配体、H3PO3和Ni2 离子的作用.采用动电位扫描法测量合金电沉积时的阴极极化曲线.所用仪器有DHW型恒电位仪(延边电化学仪器厂),YEW-TYPE-3086型X-Y函数记录仪(四川仪表四厂).电极:阴极为1cm2铜片,阳极为5cm2Pt片,参比电极:饱和甘汞电极(SCE).实验溶液广:NiCl2·6H2O25g/L,NH4Cl9g/L,L1-… 相似文献
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采用循环伏安、线性扫描和恒电位阶跃电化学方法结合扫描电镜研究了不同浓度的丙烯基硫脲(ATU)对NH3-NH4Cl-H2O体系镍在玻碳电极上的电沉积过程的影响. 循环伏安测试、线性扫描以及恒电位暂态曲线一致表明ATU的加入对镍电沉积具有阻化作用,并且随着ATU浓度的增加其阻化作用增强;恒电位暂态曲线结果表明,镍的电结晶是按瞬时形核三维生长机理进行的,随外加电位负移,晶体向外生长速率增大;ATU的加入没有改变镍的形核方式,但形核数密度增大,并且减小晶体向外生长的速率;扫描电镜结果表明,ATU的加入可以细化晶粒,得到整平、致密的镍沉积层. 相似文献
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Bek R. Yu. Shuraeva L. I. Ovchinnikova S. N. 《Russian Journal of Electrochemistry》2004,40(10):1079-1083
Effect of lead hydroxy compounds on the process of electrodeposition of silver from cyanide electrolytes is studied on an electrode whose surface is renewed in solution by cutting off a thin layer of metal. This permitted to perform the study on both the freshly renewed electrode and at controlled values of the time of the electrode contact with solution t. Shown is that on the freshly renewed electrode (t<1 s) the presence in the solution of lead ions in concentrations c
1 on the order of 10–5 M leads to the process depolarization only in the initial portion of a polarization curve. With c
1 increased to 10–4 M the effect of depolarization extends on the entire polarization curve. Keeping the electrode in solution after the renewal of the metal surface magnifies depolarization, and the greater the concentration c
1, the shorter the time period t required to achieve the same effect. These regularities are attributed to catalytic influence of lead adatoms, whose surface concentration depends on c
1 and t, as well as on the intensity of their incorporation in the silver deposit. 相似文献
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Silver (Ag) nanoparticles were directly electrodeposited on multi-walled carbon nanotubes (MWCNT) in AgNO3/LiNO3 containing EDTA (ethylenediaminetetraacetic acid). The structure and nature of the resulting Ag/MWNT composite were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), and the distribution shape of Ag nanoparticles was found to be dependent on the presence of EDTA. The modified electrode showed excellent electrocatalytic activity to redox reaction of hydrogen peroxide and the mechanism of hydrogen peroxide was partly reversible procession with oxidation and reduction peaks at 0.77 and -0.83 V, respectively. The oxidation and reduction peak currents were linearly related to hydrogen peroxide concentration in the range of 1×10^-6-3×10^-4 and 1 ×10^-8-7× 10^-4 mol·L^-1 with correlation coefficients of 0.996 and 0.986, and 3s-detection limit of 9 × 10^-7 and 7 × 10^-9 mol·L^-1. 相似文献
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采用恒电位电沉积方法, 在未经修饰的ITO导电玻璃基底上通过控制实验条件制备出不同形貌的纳米ZnO结构, 而在经过ZnO纳米粒子膜修饰后的ITO导电玻璃基底上, 制备出透明、高取向、粒径小于30 nm的ZnO纳米棒阵列. 用扫描电子显微镜(SEM)、X射线衍射(XRD)以及透射光谱对制备出的ZnO纳米棒阵列的结构、形貌和透明性进行了表征. 测试结果表明, ZnO纳米棒阵列的平均直径为21 nm, 粒径分布窄, 约18~25 nm, 择优生长取向为[001]方向, 垂直于基底生长. 当入射光波长大于400 nm时, ZnO纳米棒阵列的透光率大于95%. 相似文献
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Coatings containing Fe-Si or Si particles were electrodeposited on 3.0%(mass fraction) Si steel sheets. The surface morphology, the cross-section and the silicon content of coating have been investigated, respectively. It was found that the number of particles on the coating surface and cross-section significantly decreased with increasing silicon content in the applied particles, leading to a decrease of the silicon content of coatings. About 10.2% silicon content of coatings deposited with Fe-30%Si particles can be obtained, whereas that for Si particles was only 2.9% at a particle concentration of 100 g/L and current density of 2 A/dm2. This is mainly attributed to the conductivity of applied particles. High conductivity can promote the co-deposition of the particles. With increasing silicon content in the particles, their conductivity decreased sharply, resulting in the decrease of silicon content of coatings. Present work may initiate a new method to modify the particle content of the composite coatings via changing the conductivity of the particles during the composite electrodeposition. In this paper, a possible mechanism was proposed to explain the phenomena. 相似文献
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银微盘电极上L-半胱氨酸的伏安行为研究 总被引:4,自引:0,他引:4
银微盘电极上L-半胱氨酸的伏安行为研究方宾,方惠群,陈洪渊(南京大学化学系,南京,210093)关键词银微盘电极,L-半胱氨酸,循环伏安法由碳纤维、金、铂、铱等材料制成微电极的研究国内、外报道甚多[1~5],但以银为材料制成的电极在生化物质方面的研究... 相似文献