This investigation first proposed that open-circuit potential vs time (OCP-t) is a novel nonlinear potential step controlled by redox reaction and nucleation. A novel thermodynamic model of OCP-t is obtained for electroless deposition of Ni on Pd-activated p-type silicon 100. Thermodynamic transient properties such as capacity of double layer C, surface charge density q, interfacial tension, and resistance of chemical reaction Rr are calculated. Results show that the variation of OCP is dependant on the interfacial double layer. The breakdown and rearrangement of the double layer causes surface charge density step, which triggers momentary nucleation of Ni on the substrate. Results also show that reductant pulses would be an effective way to speed nuclei growth.

This work describes a study of the underpotential deposition (UPD) of Sn2+ on a polycrystalline gold disc electrode using cyclic voltammetry (CV) and chronocoulometry (CC). Sn2+ ions showed well-defined peaks from UPD and UPD stripping (UPD-S) in 1 mol/L HCl solutions, while bulk deposition (BD) and BD stripping (BD-S) of the ions were also observed. The measured UPD shifts, DEUPD, between the UPD-S and the BD-S peaks were more than 200 mV. The UPD charge and the surface coverage of tin were measured by CC. A new method for determining Sn2+ was therefore developed, based on the excellent electrochemical properties of the Au/Sn UPD system. A plot of the UPD-DPASV (differential pulse anodic stripping voltammetry) signal versus the Sn(II) concentration was obtained for [Sn(II)] of 1.98

Amide-functionalized humic acids (AHA) was synthetized by two step reactions, in which humic acids first reacted with thionyl chloride(SOCl2) and then reacted with ammonia liquor. The AHA was characterized by Fourier transform infrared (FTIR) spectra and elemental analysis method. The reaction properties between AHA and mercury ions(I,II) were investigated at an AHA chemically modified carbon paste electrode (AHACMCPE) using cyclic voltammetry (CV) and linear sweep stripping voltammetry (LSSV). Moreover, the binding behavior of numerous other ions at the AHA-CMCPE was also tested. In an open circuit, Both HgI and HgII were accumulated from a stirred 0.1M H2SO4 solution onto the AHACMCPE. The subsequent electrochemical measurement was performed in another clean supporting electrolyte of 0.5M H2SO4. Factors affecting the accumulation and electrode reaction steps were investigated and an optimized procedure for quantifying mercury was developed. Under optimized conditions, a calibration plot for mercury concentration in the range 4.98

An ethylenediamine fixed humic acid preparation (EHA) was synthesized by the interaction between the etheride of humic acid(HA) and ethylenediamine. The EHA was characterized by Fourier transform infrared spectrometry and elemental analysis, and employed to prepare a chemically modified electrode. Based on EHA-containing carbon paste electrode, the accumulation and electrochemical behavior of gold(III) were investigated by cyclic voltammetry and differential pulse stripping voltammetry (DPSV). The proposed measurement involves a medium exchange procedure in which the preconcentration step was accomplished in a solution of 0.35 M HCl and the subsequent electrochemical step performed in a supporting electrolyte of 0.8 M HCl. The oxidizing current (I'pa2) obtained by DPSV was proportional to the concentration of the Au(III) ion in a range of 3.5×10-6～5.1×10-8 M. The sensitivity and selectivity of the proposed method are obviously better than that of results obtained by using a chemically modi®ed carbon paste electrode of ordinary HA.

The fabrication of Sn-Se compounds, at room temperature by electrochemical atomic layer epitaxy (EC-ALE) is reported. EC-ALE involves the use of surface limited reactions to form atomic layers of the elements making up a compound (Sn and Se) in a cycle. Cyclic voltammograms were used to determine approximate deposition potentials for each element. The amperometric I-t method and differential pulse anodic stripping voltammetry were used to deposit and study the processes involved in a continuous cycling deposition which were used to form thin films of the compound. Through the analysis of the I-t transients and the stripping voltammograms it is possible to establish the formation of Sn-Se compounds. Taking into account the charges involved in the I-t deposition process, a general reaction scheme that considers the formation of SnSe2, SnSe2-x and SnSe compounds is proposed.