Nickel-based electrocatalysts for energy-related applications: Oxygen reduction, oxygen evolution, and hydrogen evolution reactions

The persistently increasing energy consumption and the low abundance of conventional fuels have raised serious concerns all over the world. Thus, the development of technology for clean-energy production has become the major research priority worldwide. The globalization of advanced energy conversion technologies like rechargeable metal-air batteries, regenerated fuel cells, and water-splitting devices has been majorly benefitted by the development of apposite catalytic materials that can proficiently carry out the pertinent electrochemical processes like oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and water hydrolysis. Despite a handful of superbly performing commercial catalysts, the high cost and low electrochemical stability of precursors have consistently discouraged their long-term viability. As a promising substitute of conventional platinum-, palladium-, iridium-, gold-, silver-, and ruthenium-based catalysts, various transition-metal (TM) ions (for example, Fe, Co, Mo, Ni, V, Cu, etc.) have been exploited to develop advanced electroactive materials to outperform the state-of-the-art catalytic properties. Among these TMs, nickel has emerged as one of the most hopeful constituents due to its exciting electronic properties and anticipated synergistic effect to dramatically alter surface properties of materials to favor electrocatalysis. This review article will broadly confer about recent reports on nickel-based nanoarchitectured materials and their applications toward ORR, OER, HER, and whole water splitting. On the basis of these applications and properties of nickel derivatives, a futuristic outlook of these materials has also been presented.