Effect of surfactants on electrocatalytic performance of copper nanoparticles for hydrogen evolution reaction

Abstract

In this work, for the first time, effect of different types of surfactants on hydrogen evolution reaction (HER) is studied. In this way, sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide (CTAB), and t-octyl phenoxy polyethoxy ethanol (Triton X-100, TX-100) are used as anionic, cationic and non-ionic surfactants, respectively. Copper nanoparticles (nano-Cu) are simply electrodeposited on carbon paste electrode (CPE) and their performances for HER were examined in acidic medium. The presence of the surfactants in H2SO4 solution causes to improvement of hydrogen generation on the bare CPE in order of TX-100˃SDS˃CTAB. The results show that the surfactants can improve the electrocatalytic activity. It was found that lowering the interfacial tension between the electrode and electrolyte favored the diffusion of hydronium ions. Electrocatalytic activity of the nano-Cu/CPE for HER is found to increase in order of SDS˃TX-100˃CTAB. Also, successive potential cycling in the presence of SDS on nano-Cu/CPE does not reduce its performance towards HER. The Tafel slopes for the HER are found to be 6.44, 5.86 and 6.02V−1dec−1 on the nano-Cu/CPE in presence of SDS, CTAB and TX-100, respectively. The kinetic parameters show that Volmer step controls the HER.