Figure 2

Voltammograms of; A) Ni²⁺; B) Co²⁺; C) Fe²⁺; D) Zn²⁺; E) Ni²⁺, Co²⁺; F) Ni²⁺, Co²⁺, Fe²⁺; G) Ni²⁺, Co²⁺, Zn²⁺; H) Ni²⁺, Co²⁺, Fe²⁺, Zn²⁺; from aqueous solution, with scan rate of 10 mV s^-1 with the presence (solid line) and absence (dash line) of PPMF (9 T). When SCE and platinum wire were chosen as a reference and counter electrodes respectively. Concentration of each ions in solutions was 0.01 M.