Cyclic voltammetry was performed using IviumStat (Ivium
Technologies, the Netherlands) (Software: Iviumsoft and Faraday
cage: BASI cell stand C3) in a three-electrode configuration, which
employs Al1050 as the working electrode, platinum wire as the
counter electrode, and Ag/AgCl as the reference electrode. The
working electrode was carefully polished with alumina slurry and
cleaned in an ultrasonic bath before each experiment.