Influence of the external electric field distribution on α-Ni(OH)2 electrochemical-synthesis from a NiCl2 solution

Abstract

Electrolytic systems of a symmetric, an asymmetric and a two-compartment were established in the present work to investigate the effect of the external electric field distribution on α-Ni(OH) 2 electrochemical-synthesis from a NiCl 2 solution. Results demonstrate the sample particle size increased in the order of symmetric, two-compartment and asymmetric systems, with a sharpened diffraction peak of the (1 0 1), (0 1 5) and (1 1 0) plane, and a broadened diffraction peak of (0 0 3) plane. However, the reversibility of the redox reactions and the energy transferred in the redox reactions in the electrodes assembled by the samples from the three electrolytic systems increased based on the contrary order. In terms of the electrolysis process, the energy consumption per unit mass increased in the order of symmetric, two-compartment and asymmetric systems. The catholyte pH for both symmetric and asymmetric systems were more stable than that for the two-compartment system. The external electric filed distribution affected the transportation of Ni 2+ from the anolyte to the catholyte. At the end of electrolysis, the Ni 2+ concentration in the anolyte of two-compartment system was obviously higher than that of symmetric and asymmetric systems.