Synthesized Transition Metal-Based Nanosheet Electrocatalysts for Alkaline Water Electrolyzers

Hydrogen is a completely carbon-free energy source with high energy density and conversion efficiency, and it has become a promising alternative to fossil fuels. The best way to produce green hydrogen without carbon emissions is through water electrolysis. Water electrolysis involves two reactions: the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). Although HER is produce hydrogen, production efficiency is more directly associated with OER.<br/>The two most famous water electrolysis technologies are alkaline water electrolyzers (AWEs) and proton exchange membrane water electrolyzers (PEMWEs). The recently developed AEM electrolyzer exhibit both the advantage of AWE, PEM electrolyzers mentioned above. This electrolyzer can greatly reduce the ohmic loss using solid ionomer membrane and is operated in alkaline condition, allowing the use of non-precious metals as electrocatalysts. Although, the cost of hydrogen production can be reduced by using non-precious metal electrocatalysts, the performance of AEM water electrolyzers is still lower than that of PEM electrolyzers due to the sluggish electrocatalyst kinetics for oxygen evolution reaction (OER). To overcome this obstacle, it is strongly necessary to develop high-performance and cost-effective OER elctrocatalysts.<br/>In this study, we developed Cu(OH)2 nanosheets onto ZIF67 for OER electrocatalyst. The obtained material, labeled as CuOH2@ZIF67, improves its conductivity and intrinsic activity. In addition, the AEM electrolyzer equipped with CuOH2@ZIF-100 shows better performance at high current densities than that of RuO2 by reducing the mass transport of the AEM electrolyzer. Our approach is suitable for large-scale hydrogen production as an OER catalyst since it does not require precious metals and enables cost-effective, high-efficiency catalyst production through simple synthesis