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1999

Physical Sciences and Mathematics

Articles 1 - 11 of 11

Full-Text Articles in Nanoscience and Nanotechnology

Photoelectrochemical Studies On The Tio_2 Nanostructured Porous Film Sensitized By Cyanine Dye, Li Zhang, Maizhi Yang, Xuebin Qiao, Yanzhong Hao, Enqing Gao, Shengmin Cai Nov 1999

Photoelectrochemical Studies On The Tio_2 Nanostructured Porous Film Sensitized By Cyanine Dye, Li Zhang, Maizhi Yang, Xuebin Qiao, Yanzhong Hao, Enqing Gao, Shengmin Cai

Journal of Electrochemistry

The photoelectrochemical behaviors of the TiO 2 nanostructured porous film sensitized by cyanine dye were investigated in this paper.The results showed that the excitaed state level matched the conduction band edge of TiO 2 nanoparticle.Therefore the sensitization of the dye can increase the photocurrent intensity of the TiO 2 nanostructured electrode obviously and results in a red-shift of optical absorption from the ultra_violet region to the visible.As a result,the light_to _electricity conversion efficiency was improved evidently,the maximum value of IPCE has reached 12.1%.

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Surface Enhanced Raman Spectroscopic Study Of Scn - Adsorbed At The Copper And Gold Nanowire Arrays, Jianlin A Yao, Guoping Pan, Kuanhong Xue, Yong Xie, Jing Tang, Bin Ren, Dongmei Sun, Bingwei Mao, Zhongqun Tian Nov 1999

Surface Enhanced Raman Spectroscopic Study Of Scn - Adsorbed At The Copper And Gold Nanowire Arrays, Jianlin A Yao, Guoping Pan, Kuanhong Xue, Yong Xie, Jing Tang, Bin Ren, Dongmei Sun, Bingwei Mao, Zhongqun Tian

Journal of Electrochemistry

Two_dimensional arrays of Cu and Au nanowires have been fabricated by template synthesis method, using the anodic aluminum oxidation films as the template. The morphology of the nanowire array was monitored by atomic force microscope (AFM) in the dissolution processes of the alumina film. Based on the probe molecule strategy, the spectral feature of SCN - adsorbed at the Cu and Au nanowires with different diameters has been investigated by surface enhanced Raman spectroscopy (SERS). The results reveal that the intensity of the SERS bands depends on the length of the exposed nanowires. The C≡N stretching vibration frequency (ν CN …

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Prparation Of Nanocrystaline Tio_2(Anatase)With High Thermal And Textural Sability By Electrochemical Method, Daobao Chu, Xingfu Zhou Nov 1999

Prparation Of Nanocrystaline Tio_2(Anatase)With High Thermal And Textural Sability By Electrochemical Method, Daobao Chu, Xingfu Zhou

Journal of Electrochemistry

Titanium alkoxides were prepared by anodic dissolution of metallic titanium in absolute ethanol in the presence of HN(C 2H 5) 2·HCl (electro_conductive additives).The solution was directly hydrolyzed to prepare nanocrystalline of TiO 2 (about 10nm)by a sol_gel process.The precursor gels was calcined at T =450 ℃ and 720 ℃for 30 min,and nanocrystalline of TiO 2 (anatase) with high textural and thermal stability was obtained.FTIR,XRD,TEM,were used to characterize the structure of titanium alkoxides and nanocrystalline of TiO 2.The characteristics of nanocrystalline of TiO 2 was depended on the properties of titanium alkoxides.The Ti(OEt) 4 as a source of titanium yielded the …

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Preparation And Ionic Conductivity Of Nanometer_Sized Li 2+X Gd X Si 1+X O 3 By The Sol_Gel Method, Rufen Chen, Xiuqin Song, Huating Liu Aug 1999

Preparation And Ionic Conductivity Of Nanometer_Sized Li 2+X Gd X Si 1+X O 3 By The Sol_Gel Method, Rufen Chen, Xiuqin Song, Huating Liu

Journal of Electrochemistry

Li 2+x Gd xSi 1-x O 3( x =0～0.15) samples have been prepared by the Sol_Gel method. The power samples were characterized by DTA_TG, XRD and TEM. Ionic conductivity of the sinter was determined by means of A_C impedance measurements. The experimental results showed that the range of solid_solution was 0< x ≤0.09, while the conductivity of samples raised with increasing amount of Gd 2O 3 added, and average grain size of samples was 80 nm. In comparing with the samples by the conventional solid state reaction, the samples prepared by Sol_Gel method required lower temperature and presented higher ionic conductivity.

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In Situ Ftirs Studies Of The Electrochemically Induced Coupling Of Osmium Nitrido Species In Acetonitrile, Shengpei Chen, Shigang Sun Aug 1999

In Situ Ftirs Studies Of The Electrochemically Induced Coupling Of Osmium Nitrido Species In Acetonitrile, Shengpei Chen, Shigang Sun

Journal of Electrochemistry

he search for inorganic systems that can cleave N≡N triple bond under mild conditions is an important subject. It is well known that the metal nitrido (M≡N) complexes are possible intermediates in nitrogen fixation [1] and in the reduction of nitrite to ammonia [2,3] . Recently, these complexes have received considerable attention [4～9] for their intriguing photochemical and electrochemical properties. Among different high valence metal nitrido complexes, some osmium(VI) nitrido species are stable enough to be isolated [4～10] , demonstrating that the study on this class of complexes becomes feasible. Meyer and co_workers [4] have reported the electrochemical interconversion between …

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The Adsorption Stability Of Interface Corrosion Inhibitor, Fuxing Gan, Dihua Wang, Jinyun Zou May 1999

The Adsorption Stability Of Interface Corrosion Inhibitor, Fuxing Gan, Dihua Wang, Jinyun Zou

Journal of Electrochemistry

Some new results on the adsorption stability of interface corrosion inhibitor are presented. The concept of adsorption stability and the factors influencing the adsorption stability were discussed. It is shown that the anodic desorption potential can be employed to evaluate the adsorption stability of the inhibitor as an empirical character in some conditions. Electrochemical oscillations phenomena were observed for the first time on a rotating iron electrode in H2SO4 solution containing organic inhibitor in the active potential region. These potentiostatic current oscillations can occur under cathodic polarization, as well as under anodic plarization. The oscillation period, amplitude, incubation time and …

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In Situ Ftir Spectroelectrochemical Study Of Palladium Hexacyanoferrate Thin Film Deposited On Glassy Carbon Electrode, Aili Bo May 1999

In Situ Ftir Spectroelectrochemical Study Of Palladium Hexacyanoferrate Thin Film Deposited On Glassy Carbon Electrode, Aili Bo

Journal of Electrochemistry

The electrochemically deposited Palladium hexacyanoferrate thin film on Glassy Carbon electrode (PdHCF|GC) has been studied in HCl, KCl and NaCl solutions by in_situ external reflection FTIR spectroelectrochemical technique. It is found that the behavior of the electroactive PdHCF film can be understood in terms of two states: Pd2Fe(II)(CN)6 formed in the inner layer and (M+)2Fe(II)(CN)6 (M+: electrolyte cation) formed in the outer layer. The inner layer is oxidized at Em=0.87 V in 1 mol/L KCl, while for the outer layer Em=0.77 V(vs. Ag/AgCl). In 1 mol/L NaCl or HCl solutions, half_wave potentials of these two layers are not well resolved, …

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Preparation And Application Of Gold_Film On The Surface Of Bacterial_Modified Carbon Paste Electrode, Rongzong Hu, Yanping Ruan, Hao Xu, Jinkun Fu, Weide Zhang, Wenyun Hu May 1999

Preparation And Application Of Gold_Film On The Surface Of Bacterial_Modified Carbon Paste Electrode, Rongzong Hu, Yanping Ruan, Hao Xu, Jinkun Fu, Weide Zhang, Wenyun Hu

Journal of Electrochemistry

A novel method for preparation of gold_film composed of ultra_fine gold particles was reported in this paper. The gold_film was prepared by electrochemical method on the surface of the paste electrode modified with the strain Bacillus sp. D01 which has strong ability to absorb and reduce Au3+. In addition, this paper reported an experimental method of determining trace amount of Cu2+ in water solution using cathodic stripping analysis to estimate the performances of the obtained gold_film. The experimental results indicated that this new method for preparation of gold_film is simple. The obtained gold_film electrode is stable and sensitive to determining …

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Modeling The High-Speed Switching Of Far-Infrared Radiation By Photoionization In A Semiconductor, Thomas E. Wilson May 1999

Modeling The High-Speed Switching Of Far-Infrared Radiation By Photoionization In A Semiconductor, Thomas E. Wilson

Physics Faculty Research

Data from an earlier study [T. Vogel et al., Appl. Opt. 31, 329 (1992)] on the subnanosecond switching of 119-μm radiation in high-resistivity silicon by pulsed UV laser radiation, is compared with a refined one-dimensional numerical multilayer model accounting for the generation, recombination, and diffusion of the free carriers on the resulting far-infrared optical properties of the silicon. The inclusion of recent measurements for carrier-density and temperature-dependent transport parameters leads to improved agreement between experiment and theory.

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Electrochemical Surface Characterization Of Titanium Alloy(Ti_6al_4v)), Jianzhong Chen, Qingliang Gao, Zhongyi Wang, Wenjing Xue Feb 1999

Electrochemical Surface Characterization Of Titanium Alloy(Ti_6al_4v)), Jianzhong Chen, Qingliang Gao, Zhongyi Wang, Wenjing Xue

Journal of Electrochemistry

With its low density and high strength ratio, titanium alloy(Ti_6Al_4V) has become one of the most important materials both in the fields of aerospace and biomedical assays. Recently, titanium alloy was used as the implantation materials in human body because of its biocompatibility. The elecrochemical impedance techniques were then used to investigate the corrosion behavior of this material in hydrochloride and sulfuric acid solutions. A comparison between impedance spectra and anodic polarization over the correlated range of applied voltage confirms that AC impedance data can be used as a powerful tool for surface characterization of titanium alloy.

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Studies Of Electrochemical Characteristics Of Pasted Nickel Hydroxide Electrode With Surface Deposited Cobalt, Xianyou Wang, Yunshi Zhang, Jie Yan, Zheng Zhu, Huatang Yuan, Deying Song Feb 1999

Studies Of Electrochemical Characteristics Of Pasted Nickel Hydroxide Electrode With Surface Deposited Cobalt, Xianyou Wang, Yunshi Zhang, Jie Yan, Zheng Zhu, Huatang Yuan, Deying Song

Journal of Electrochemistry

The surface of the spherical nickel hydroxide particles used as an active material in pasted nickel electrodes is surface_deposited with cobalt. This paper investigated the effects of the amount of cobalt deposit on the characteristics of nickel hydroxide electrode. The performances of the electrode, such as discharge capacity, utilization of active material and reversibility of Ni(OH) 2/NiOOH redox reaction, were studied by comparing the charging/discharging curves and cyclic voltammograms. The mechanism of action of cobalt deposits has been described in terms of the electrochemical impedance spectroscopy of nickel hydroxide electrode.

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