“…The commercial Ir/Ru- and Pt-based precious metal catalysts have excellent semireactive electrocatalytic effects for the OER and HER, respectively, , but high cost and limited abundance hinder their wide applications. , Many research works have demonstrated that alloying by incorporating other transition metals can reduce the relative content of precious metals in the catalyst to cut down cost, and the electrocatalytic performance can be improved by the adjustment of the electronic structures and surface properties. , Particularly in recent years, manufacturing surface defect lattices on the alloy catalyst is emerging as a great potential for boosting electrocatalytic HER and OER activities, because it can effectively adjust the charge distribution, molecular orbital hybridization, active center on the surface, and the adsorption of reactants. − For instance, by mixing different defective structures into the atomic thin CoSe 2 nanoband, Fe doping and Co vacancy jointly optimized the electron states, so the binding energy of OH* was greatly reduced, achieving high catalytic OER activity. The high concentration defects in Mo 1– x Nb x Se 2 nanoparticles can significantly enhance HER performance, because they become the catalytic active sites and are conducive to the adsorption of H atoms. A large number of defects can be produced on the RhCu NTs surface after pickling, which promotes the transfer of electrons and adsorption of reactants, thus improving the electrocatalytic performance. Sial et al reported that a number of additional active edge sites can be provided on the multishell hollow NiCoFe alloy balls with defects to improve HER activity. In consequence, it may obtain unexpected high HER and OER activities by developing new alloy catalysts rich in defects.…”