ZIF-8@Au nanoparticles as a high-performance trifunctional electrocatalyst for overall water splitting and methanol oxidation

We report the use of ZIF-8@Au nanoparticles electrocatalyst for overall water splitting and methanol oxidation. In an alkaline medium, ZIF-8@Au produced good OER (oxygen evolution reaction) activity and needed only 160 mV overpotential to attain 10 mA cm⁻² current density, whereas HER (hydrogen evolution reaction) needed an overpotential of −510 mV. Additionally, the achieved alkaline water splitting process only necessitated a cell voltage of 1.9 V to obtain 10 mA cm⁻² current density. These figures are better/in line with those reported for both noble and non-precious metal catalysts in existing literature. The newly developed catalyst was also effectively utilized for the methanol oxidation. The electrocatalytic performance of Au embedded in ZIF-8 nanostructures towards OER, HER, and methanol oxidation can be correlated with the high dispersion of Au nanoparticles in ZIF-8 framework, which enhances its electro-catalytic activity. These findings indicated that combining highly active Au with a ZIF-8 semiconductor improved overall splitting of H₂O.