The rational design of efficient and cost‐effective electrocatalysts for oxygen evolution reaction (OER) with sluggish kinetics, is imperative to diverse clean energy technologies. The performance of electrocatalyst is usually governed by the number of active sites on the surface. Crystalline/amorphous heterostructure has exhibited unique properties and opens new paradigms toward designing electrocatalysts with abundant active sites for improved performance. Hence, Fe doped Ni–Co phosphite (Fe‐NiCoHPi) electrocatalyst with cauliflower‐like structure, comprising crystalline@amorphous core–shell nanorod, is reported. The experiments uncover that Fe is enriched in the amorphous shell due to the flexibility of the amorphous component. Further density functional theory calculations indicate that the strong electronic interaction between the enriched Fe in the amorphous shell and crystalline core host at the core–shell interface, leads to balanced binding energies of OER intermediates, which is the origin of the catalyst‐activity. Eventually, the Fe‐NiCoHPi exhibits remarkable activity, with low overpotentials of only 206 and 257 mV at current density of 15 and 100 mA cm−2. Unceasing durability over 90 h is achieved, which is superior to the effective phosphate electrocatalysts. Although the applications at high current remain challenges , this work provides an approach for designing advanced OER electrocatalysts for sustainable energy devices.

The development of highly active and durable electrocatalysts with low Pt content for key reactions (hydrogen evolution reactions) in acidic electrolyte environments is desirable but remains an open challenge for clean and efficient energy conversion. Here, homogeneous, and unique Pt 0.23 Mn 0.42 Ni 0.35 flower-like nanostructure were firstly synthesized by a simple low-temperature oil-phase strategy. These Pt 0.23 Mn 0.42 Ni 0.35 cata-lysts exhibit a significantly increased electrochemically active surface area and excellent electrical conductivity due to their alloy nature, uniform, and unique channel-rich morphological characteristics. The new-type catalyst shows an ultra-small overpotential of 23 mV at a current density of 10 mA cm À 2 , high mass activity (7.61 A mg À 1 Pt at À 0.07 V) and excellent stability in acidic media.