Sacrificial Hard‐Template‐Derived Hierarchical HC@Co‐2 With Vertical Cobalt Silicate Nanosheets for Efficient Electrocatalytic Oxygen Evolution Reaction

ABSTRACT

Developing efficient non‐noble metal electrocatalysts is crucial for advancing the oxygen evolution reaction (OER) in electrochemical water splitting. OER involves multi‐step proton‐coupled electron transfer, leading to intrinsically sluggish kinetics and elevated reaction overpotentials. Herein, a core‐shell structured HC@Co‐2 catalyst is synthesized via a sacrificial hard‐template in situ hydrothermal strategy. Vertically aligned cobalt silicate nanosheets are uniformly grown on hollow carbon spheres, forming a well‐defined hierarchical nanostructure. The as‐prepared HC@Co‐2 catalyst exhibits excellent OER performance. It delivers an overpotential of 377 mV at a current density of 10 mA cm ⁻² in alkaline electrolyte. It also maintains stable OER activity over 108 h of continuous operation at the same current density with negligible activity decay. The outstanding catalytic performance benefits from its hierarchical nanostructure. The hollow carbon skeleton enhances electrical conductivity and promotes electrolyte diffusion. The vertical nanosheets facilitate mass transport. This work provides a feasible strategy for designing high‐performance layered nanostructured OER electrocatalysts.