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Ni-W-P coatings were electrodeposited on copper substrates by pulse electroplating. Effects of electrolyte pH (1-3), temperature (40–80 °C), average current density (1–7 A/dm2) and pulse frequency (200–1000 Hz) on deposition rate, structure and corrosion resistance performance of Ni-W-P coatings were studied by single factor method. Surface morphology, crystallographic structure and composition of Ni-W-P coatings were investigated by means of scanning electron microscopy, X-ray diffractometry and energy dispersive X-ray spectroscopy, respectively. Corrosion resistance performances of Ni-W-P coatings were studied by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5% NaCl solution (mass fraction) and soil-containing solution. It was found that the pulse electroplated Ni-W-P coatings have superior corrosion resistance performance and the electroplating parameters significantly affect the structure and corrosion resistance performance of Ni-W-P coatings. The optimized parameters of pulse electroplating Ni-W-P coatings were as follows: pH 2.0, temperature 60 °C, average current density 4 A/dm2, and pulse frequency 600 Hz. The Ni-W-P coating prepared under the optimized parameters has superior corrosion resistance (276.8 kΩ) and compact surface without any noticeable defect.

Ag-based nanocatalysts exhibit good catalytic activity for the electrochemical reduction of organic halides. Ag-Ni alloy nanoparticles (NPs) were facilely prepared by chemical reduction, and the as-prepared nanocatalysts were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The electrocatalytic activity of Ag-Ni NPs for benzyl chloride reduction was studied in organic medium using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results show that the addition of Ni element can obviously decrease the size of Ag-Ni NPs, shift the reduction peak potential ( f p ) of benzyl chloride positively, and increase the catalytic activity of Ag-Ni NPs. However, when the Ni content reaches a certain value, the catalytic activity of Ag-Ni NPs decreases. Meanwhile, the synergistic catalytic effect of Ag-Ni NPs was also discussed.

The electro-polymerization behavior of aniline in reverse (W/O) microemulsion was investigated. The experiment results show that the cyclic voltammetry polymerization behavior of aniline in W/O microemulsion is different from that in aqueous solution remarkably. With the increase of scan cycle, the oxidation potential shifts positively and the reduction potential shifts negatively, i.e., the redox potential difference increases. H+ apparent concentration affects the aniline polymerization evidently. When H+ concentration is lower than 0.08 mol/L, the electro-polymerization of aniline is difficult. With the increase of H+ concentration, the polymerization current of aniline increases gradually. Only when H+ concentration is high enough (0.5 mol/L), aniline can be well electro-polymerized. Moreover, under the same condition, the aniline polymerization current in W/O microemulsion is higher than that in aqueous solution. The scanning electron microscopy image shows that the deposited polyaniline (PANI) has uniform fiber morphology with diameter of about 100 nm. Further study result suggests that the electrochemical activity of the PANI in HCl is similar to that of the PANI prepared in aqueous solution.