Fig. 5From: Sol-gel Synthesis, Photo- and Electrocatalytic Properties of Mesoporous TiO2 Modified with Transition Metal Ions a Current-voltage curves for oxygen reduction in solution of 0.9% NaCl at the electrodes: (1)—TiO2, (2)—TiO2/Ni2+, (3)—TiO2/Co2+, (4)—TiO2/Cu2+ (1% of dopant). b Current-voltage curves for oxygen reduction in solution of 0.9% NaCl at the TiO2/Mn3+ electrode: (1)—first cycle, (2)—after cycling; v = 10 mV s−1 Back to article page