Title : In situ addition of graphitic carbon into nico2o4/coo composite: Its effect on oxygen evolution reaction
Abstract:
The search of cost-effective, high-performance and long term stable catalyst for the water splitting reaction is gained a significant importance in utilizing renewable energy for futuristic applications very effectively. The objective of the current study is to investigate NiCo2O4/CoO and graphitic carbon, pooled in to a single composite material, to demonstrate excellent catalytic activity towards oxygen evolution reaction (OER). In this study, NiCo2O4/CoO composite with varied amount of graphitic carbon has been prepared using a simple one-pot synthesis, wherein the advantages of the proposed method includes rapid synthesis (3 minutes), environmentally benign and in situ retaining of graphitic carbon. The effect of graphitic carbon present in NiCo2O4/CoO composite on the catalytic performance towards OER was systematically investigated where the NiCo2O4/CoO composite with highest graphitic carbon exhibits enhanced OER kinetics in terms of lower overpotential (η = 323 mV at 10 mA cm-2), high current density (77 mA/cm2 at 1.5 V) and turnover frequency (1.53 x 10-2), and good long term stability (500 potential cycles) under the present experimental conditions. This overpotential of 323 mV is lower than the potential required by the traditional catalyst IrO2 (340 mV) and RuO2 (350 mV) to generate current density of 10 mA cm-2. The reason behind this good catalytic activity and stability of the proposed composite was discussed in depth.
