Low‐cost Co and Ni MOF s/ CP s as Electrocatalysts for Water Splitting Toward Clean Energy‐Technology

Experts in clean energy technologies propose the use of hydrogen as fuel instead of fossil fuels, which are limited in supply and emit greenhouse gases during their combustion. However, even though hydrogen is the most abundant element on the Earth, hydrogen gas is not commonly found in pure form; instead, it is usually bound in compounds such as water or hydrocarbons. Therefore, hydrogen gas is a synthetic fuel in practicality and must be produced. For the resulting energy to be completely clean, the hydrogen must be produced using clean, renewable energy sources. Currently, most hydrogen is produced using fossil fuels, and only c. 5% is produced using water splitting; however, the high cost of the water-splitting process limits its accessibility for the production of hydrogen of high purity and, as a result, for applications where this high purity is needed. Much of this cost is due to expensive electrocatalysts, which are typically used to reduce the associated overpotential and the high energy input to break a water molecule. Recently, the use of low-cost mono and bimetallic metal-organic frameworks/coordination polymers (MOFs/CPs) as bifunctional electrocatalysts for water splitting has gained remarkable attention. These materials have been shown to possess high electrocatalytic activity for both hydrogen evolution (HER) and oxygen evolution (OER) reaction. In this chapter, the research results of Co(II) and Ni(II) based MOFs/CPs and derived composites as electrocatalysts for water splitting reactions are discussed.* Corresponding authors