1. BJH) pore size distribution curve was drawn for each of the samples K-300 and K-500 having pore size varies from 2 to 10 nm. These parameters suggest the mesoporous structure of the samples and this porous structure is beneficial for the electrocatalytic activity. The electrocatalytic activity of the K-0, K-300, and K-500 has been studied in alkaline and acidic electrolyte mediums using a three-electrode system. As earlier discussed in the experimental section, the working electrode has been fabricated by dispersing the catalyst over a graphite sheet;Further;The electrocatalytic activity measurement of K-500
2. Oxygen Evolution study of the fabricated catalyst: The activity of the catalyst K-500 for oxygen evolution reaction has been done in alkaline (1M KOH) and acidic (0.5 M H2SO4) electrolyte solution. The linear sweep voltammetry study for K-500 and K-300 was measured at 10 mV/s scan rate (Fig. 6a and 6b) the overpotential (?10) to reach 10 mA/cm 2 in 0.5 M in H2SO4 of the catalyst K-300 and K-500 were 234 mV and 199 mV respectively and in 1M KOH the overpotential of the samples K-300 and K-500 were 294 mV and 170 mV. The observed low overpotential for K-500 confirms the superior catalytic activity than other reported cobalt metalbased catalysts. 39-43 Shi et. al. has also reported the synthesis of N-doped graphene wrapped pure hexagonal cobalt nanosheets as an electrocatalyst towards oxygen evolution reaction which shows overpotential corresponds to 340 mV. 44 The results confirm the better catalytic efficiency of K-500 than variously reported catalysts (Table 1);The Tafel slope measured in 0.5 M H2SO4 for K-500, K-300 were 72
3. Electrocatalysis for the oxygen evolution reaction: Recent development and future perspectives;N T Suen;Chem. Soc. Rev,2017