High Performance Electrocatalyst For Oxygen Reduction Reaction Of Magnetite Nanoparticle-Based As A Cathode Metal-Air Battery
The performance of magnetite electrocatalyst for oxygen reduction reaction as cathode metal-air battery through an electrochemical process has been studied. To prepare the iron oxide cathode, the formation process is produced from a scrap metal plate using an electrochemical by multi-electrode. In electrochemical test process is also carried out for the casting of iron oxide samples in the nickel foam template, with the addition of Poly-Vinylidenedifluoride (PVdF) binders and N- Methylpyrrolidone (NMP) solvent which are stirred uniformly to from a paste. This iron oxide casting is used as a metal-air battery cathode by electrocatalyst process. Based the XRD analysis, the intensity and number of peaks gradually decreased with reduced pH concentrations (7-11). The increase in pH, concentrations indicates the better quality of magnetite particles, according to the Pourbaix diagram that at concentrations of pH>8 are formed magnetite particles. As the intensity increase and the peak number are given variables of potential difference from 20 V–30 V for pH concentration pH<8. For all magnetite cathodes, the highest specific capacitance values of the CV test in 0.6M KOH were 9.93 F g-1 at a scan rate of 100 mV s-1 and 47.67 F g-1 at a scan rate of 10 mV s-1. Meanwhile, within 0.1M KOH gradually decreased from 9.93 F g-1 to 7.47 F g-1. The reaction occuring from the CV test involves a considerable value of electrocatalyst capacity with a potential energy of Eo V-1 = 0.401. From the result of the linier polarization test obtained the highest ORR electrocatalyst activity is at cathodic particle magnetite in 0.6M KOH with current density of 100 mA cm-2 and its potential is 20 mV bigger than 0.1M KOH. In addition to ORR, OER activity is also present in the anodic whic provides a catalyst boost to the electrolyte solution used. Thus, electrocatalysts for ORR and OER is an important parameter determining the cycle-life of metal-air battery.
Index Terms—magnetite, electrochemical, electrocatalyst, metal-air battery.