Abstract:

The effect of dodecyl trimethyl ammonium bromide（DTAB） and sodium dodecyl benzene sulfonate（SDBS） on the electrocrystallization of nickel hydroxide on the surface of nickel foam was studied using nickel nitrate as the nickel source and nickel foam as the substrate.The effect of adding DTAB and SDBS on the electrocrystallization kinetics of Ni（OH）₂ on nickel foam substrate was studied by physical model combined with current-time transient curves.The effects of DTAB and SDBS on the crystal structure，microstructure and capacitance of electrodeposited Ni（OH）₂ were investigated by XRD，SEM and cyclic voltammetry.The results showed that the addition of DTAB and SDBS could prolong the nucleation induction time of Ni（OH）₂ and reduce the electrocrystallization rate，so as to control the deposition morphology of Ni（OH）₂.In addition，the orientation adsorption of DTA⁺ and Na⁺ on the surface of nickel foam and Ni（OH）₂ crystal plane and the embedding of foreign anions during the deposition process had different effects on the microstructure of Ni（OH）₂.The results of XRD and SEM showed that the addition of DTAB and SDBS had little effect on the crystallinity of Ni（OH）₂ products，but had significant effect on the micromorphology of the deposited products，in which the deposition products with SDBS were fluffy porous spherical or spheroid particles.The electrochemical test results showed that the specific discharge capacitance of Ni（OH）₂ obtained by adding SDBS was the highest，which was 967.8 F/g at the scan rate of 10 mV/s.This study could provide some reference for regulating the morphologies of the electrodeposits.

Key words: Ni（OH）₂, dodecyl trimethylammonium bromide, sodium dodecyl benzene sulfonate, electrocrystallization