Inhibitive effect of anionic/ zwitterionic hybrid surfactants on the self-corrosion of anode for alkaline Al-air battery

Surfactants have been increasingly used as corrosion inhibitors in recent years. The zwitterionic surfactants can keep their amphoteric characteristics within a wide range of pH and temperature. In this research work，the self-corrosion of Al anode in alkaline electrolyte for Al-air battery is suppressed by adding a hybrid corrosion inhibitor consisting of dodecyl dimethyl betaine (DDBT) and sodium dodecylbenzene sulfonate (SDBS). The hybrid surfactant behaves as an anodic inhibitor. The results show that the optimum inhibition efficiency is 91.27 % for 1 × 10−3 M DDBT + 4 × 10−3 M SDBS. The combination of DDBT and SDBS decreases the corrosion rate of AA5052 alloy in sodium hydroxide electrolyte. The hydrophilic heads of DDBT and SDBS can adsorb on surface. The long alkyl chains in surfactant bring an increase in hydrophobicity. The hybrid surfactants have the electrostatic interaction and hydrophobic interaction, which improving the inhibition effect for the hydrogen evolution reaction. In general, the mixture of anionic and zwitterionic surfactants can provide the potential for better inhibition performance and significance for practical application.