Bimetallic Mo/Fe‐Doped CoP 2 Nanoleaf Array as a Bifunctional Electrocatalyst for Overall Water Splitting

ABSTRACT The development of efficient and stable bifunctional catalysts remains a key challenge for green hydrogen production via electrochemical water splitting. In this study, a bimetallic Mo/Fe‐doped CoP 2 nanoleaf array anchored on carbon cloth (Mo, Fe‐CoP 2 @CC) was synthesized from zeolitic imidazolate framework‐L (ZIF‐L) via an ion‐exchange and low‐temperature phosphidation approach. Dual Mo and Fe doping enables precise modulation of both the nanostructure and electronic configuration of CoP 2 , thereby promoting the formation of a three‐dimensional hierarchical architecture and enhancing its intrinsic catalytic activity. The optimized freestanding Mo, Fe‐CoP 2 @CC catalyst exhibits excellent electrocatalytic performance, achieving a low overpotential of 262 mV for the oxygen evolution reaction (OER) and 130 mV for the hydrogen evolution reaction (HER) at a current density of 10 mA cm −2 . Additionally, Mo, Fe‐CoP 2 @CC exhibits low Tafel slopes of 45.93 and 41.57 mV dec −1 . A two‐electrode alkaline electrolyzer constructed with Mo, Fe‐CoP 2 @CC reaches a current density of 10 mA cm −2 at 1.628 V, accompanied by exceptional stability, highlighting its potential for overall water splitting. In situ synchrotron radiation infrared spectroscopy and density functional theory calculations reveal that bimetallic Mo/Fe doping induces near‐thermoneutral hydrogen adsorption for HER and reduces the OER energy barrier at Fe sites. This study presents a high‐performance, nonprecious metal bifunctional catalyst for overall water splitting and provides valuable insights into the mechanisms underlying the enhanced electrocatalytic activity through heteroatom doping.