Cyclic voltammetric curves of electrotransformation of Fe2O3 nanoparticles were recorded in direct current (first
derivative) mode with potential change from -1.2 to +1.0 V (anodic scan) or from 1.0 to -1.2 V (cathodic scan) (Fig.
1, 2) at the speed of 80-90mV/s.