Experimental and Theoretical Studies of Anionic Surfactants Activity at Metal/Solution Interface: The Influence of Temperature and Hydrocarbon Chain Length of Surfactants on the Zinc Ions Electroreduction Rate

摘要

The effect of concentration of two anionic surfactants sodium 1-octanesulfonate and sodium 1-decanesulfonate in the temperature range 288-318K on the kinetics and mechanism of electroreduction of Zn2+ ions was studied using electro-chemical impedance spectroscopy (cis) and other electro-chemical methods. It was found that the process of electroreduction proceeds in two steps. To describe the mechanism of Zn2+ amalgamation, the Fawcett's models were considered: CE (chemical step C, electron transfer step E), IE (ion transfer step I, electron transfer step E) and IA (ion transfer step I, adsorption step A). The results of theoretical investigations suggest that the IE model is the most probable mechanism of the process. Both surfactants were found to exert a catalytic effect on the analyzed electrode process. The accelerating abilities of the surfactants were found to increase with the growth of the length of their hydrocarbon chain and with the increase of temperature. The observations concerning the mechanism of the electrode reaction and its acceleration caused by surfactants were confirmed by the parameters calculated from temperature dependencies.