Iron‐doped Ag/Ni₂(CO₃)(OH)₂ hierarchical microtubes for highly efficient water oxidation

Abstract Doping of foreign atoms and construction of unique structures are considered as effective approaches to design high‐activity and strong‐durability electrocatalysts. Herein, we report Fe‐doped nickel hydroxide carbonate hierarchical microtubes with Ag nanoparticles (denoted Ag/NiFeHC HMTs) through hydrolysis precipitation process. Experimental tests and density functional theory calculations reveal that Fe doping can tune the electron configuration to enhance the conductivity, markedly improve the electrochemical surface area to expose more active sites, and act as reactive centers to lower the free energy of the rate determination step. In addition, the unique hierarchical structure can also offer active sites and excellent cycling stability. Benefitting from these advantages, the as‐obtained Ag/NiFeHC HMTs show excellent oxygen evolution reaction activity, with an overpotential of 208 mV at 10 mA cm⁻² in 1.0 M KOH. Also, it could achieve long‐term stability at a current density of 20 mA cm⁻² for 24 h.