Development of Transition Metals based Electrolyser for Efficient Water Splitting

Abstract

The serious global energy crisis and environmental problems associated with the burning of hydrocarbons have compelled researchers to explore alternative sources of energy. However, generation of energy from renewable sources is a challenging task. In this context electrolysis of water is a smart approach of contributing in the energy generation domain because it stands out as a scalable technology, for which the only required inputs are water and potential. For realizing a zero carbon based economy, hydrogen must be efficiently and sustainably produced from water. However, in water splitting, oxygen evolution reaction (OER) is a sluggish half-cell reaction. Therefore, the development of efficient catalysts for speeding up OER is a key for boosting up the commercial viability of electrolysers. In this perspective researchers have employed several catalysts such as Au, Pt, Pd etc. for catalyzing OER, but their susceptibility to poisoning, high cost and limited availability have blocked the road for large scale commercialization of electrolysers. So in the search for an effective alternative, we have synthesized a novel tetra metallic electrocatalyst (Fe-Ni-Zn-Co) by a facile and low cost method compared to traditional precious noble-metal-based electrocatalysts, such as RuO2 and IrO2. The electrodeposited of the catalyst over the surface of FTO was confirmed through XRD, SEM and EDX and investigation of its catalytic activity was carried out through electrochemical techniques. The catalyst was found to accelerate OER with a very low overpotential and high current density. Linear scan voltametric results revealed that a current density of 1 mA/cm2 demanded an overpotential of just 52.6 mV in alkaline medium, thus, proving high OER efficiency of the modified FTO electrode. Furthermore, oxygen bubbles at the surface of the modified electrode offered naked eye evidence of the catalytic activity of the prepared tetra-metallic electrocatalyst during water oxidation. The aforementioned advantages of the electrochemically synthesized OER catalyst indicate that tetra metallic electrocatalysts hold great promise for contributing in clean energy production.