Another basic measure that is also often taken to determine the efficiency of the catalysts is the half-wave potential (E 1/2 ) of a reaction, which differs by the type of catalyst for that reaction. E 1/2 describes the potential to reach half the limiting current density. The limiting value of a faradaic current -the electric current generated by the reduction or oxidation of some chemical substance at an electrode -is approached as the rate of charge transfer to an electrode increases. This can be achieved by either increasing the electric potential or decreasing the mass transfer to the electrode . The E 1/2 obtained from the linear sweep voltammetry curve through the method of cyclic voltammetry is a significant indicator of ORR performance. For E 1/2 , a higher E 1/2 corresponds to a lower overpotential to reach the specific current density, resulting in a higher ORR efficiency (Design of Efficient Bifunctional Oxygen Reduction/Evolution Electrocatalyst: Recent Advances and Perspectives -Huang -2017 -Advanced Energy Materials -Wiley Online Library, n.d.).