Electrochemical chemical characterization of sample # 1-14 was done by using potentio-stat nova S11

Electrochemical chemical characterization of sample # 1-14 was done by using potentio-stat nova S11.1.Cyclic voltammetry is done for all metal oxide sample at room temperature to check the activity of catalyst for OER. This analysis was done by using Ag/AgCl as reference electrode, platinum wire as counter electrode and metal oxide catalyst as working electrode.
The results of these analysis are shown in the form of graph showing current EV vs NHE and EV vs RHE. First CV was taken for blank substrate and then with catalyst, and compared the results for current strength produced by catalyst.
Result and Discussion/ Explanation
Figure 1: The Cyclic Voltammogram of catalyst Cobalt (NaHCO3) was obtained at range of -0.5 to 1.5V Vs NHE in Fluorine-doped tin oxide (FTO) as working electrode, Platinum as counter electrode and Ag/AgCl as reference electrode. Oxidation peak appeared at 1.2V vs Ag/AgCl which is negligible in the presence of catalyst. Electrolyte is 0.1M NaHCO3 (pH=8.2) at scan rate of 20mV/s
The curve obtained with onset potential of 1.0V. The peak current is 4.2×10-3A and the peak potential is 1.5V. The catalyst use on the electrode FTO (Fluorine-doped tin oxide) show current enhancement. As, number of CV performed have cycles which are not superimposed on each other so little current enhancement was observed which show catalyst is active.

Figure 2: The Cyclic Voltammogram is obtained at range of -0.5 to 1.5V Vs NHE in FTO as blank working electrode, platinum as counter electrode and Ag/AgCl as reference electrode. Oxidation peak appeared at about 1.25 V vs RHE which is negligible in the absence of catalyst. Electrolyte is 0.1M NaHCO3 (pH=8.2) at scan rate of 20mV/s
The curve obtained with onset potential of 1.0V. The peak current is 8.5×10-3A and the peak potential is 1.5V. As, number of CV performed have cycles which are superimposed on each other so no current enhancement was observed.

Figure 3: The Cyclic Voltammogram of Cobalt was obtained at range of -0.5 to 1.5V Vs NHE in FTO as working electrode, Platinum as counter electrode and Ag/AgCl as reference electrode. Oxidation peak appeared at about 1.3 V vs NHE which show activity of catalyst. Electrolyte is 0.1M NaHCO3 (pH=8.2) at scan rate of 20 mV/s.
A slight curve is obtained with onset potential of 1.2 V. The peak current is 4.1×10-3A and the peak potential is 1.5V. The catalyst Co(NO3)2 used on substrate show current enhancement on FTO (Fluorine-doped tin oxide). As, number of CV performed have cycles which are not superimposed on each other so little current enhancement was observed which show catalyst is active.
Figure 4: The Cyclic Voltammogram of FTO blank was obtained at range of -0.5 to 1.5V Vs RHE as working electrode, Platinum as counter electrode and Ag/AgCl as reference electrode. Oxidation peak appeared at about 1.35 V vs RHE which is negligible in the absence of catalyst. Electrolyte is 0.1M NaHCO3 (pH=8.2) at scan rate of 20mV/s.
A slight curve is obtained with onset potential of 1.75V. The peak current is 8.2×10-3A and the peak potential is 2.2V. As, number of CV performed have cycles which are superimposed on each other so no current enhancement was observed.

Figure 5: Cyclic Voltammogram (CV) was performed Co(NO3)2 deposited on FTO as working electrode by applying potential from -0.5 V to 1.5 V current vs RHE, platinum as counter electrode and Ag/AgCl as reference electrode. Oxidation peak appeared at about 1.8 V vs RHE which is negligible in the presence of catalyst. Onset potential calculated for water oxidation is about 1.65 V indicating over-potential of about 430 mV. Peak current of 4.1×10-3A was achieved at a potential of 2.2 V vs RHE.
CV performed in the absence of Co shows little catalytic behavior which represents that water splitting has been taken place. While CV in the presence of catalyst showed oxidation peaks as mentioned above indicating fair catalytic activity of catalyst.