Pt Single Atom‐Doped Triphasic VP‐Ni3P‐MoP Heterostructure: Unveiling a Breakthrough Electrocatalyst for Efficient Water Splitting

Abstract Enhancement of an alkaline water splitting reaction in Pt‐based single‐atom catalysts (SACs) relies on effective metal‐support interactions. A Pt single atom (Pt SA )‐immobilized three‐phased Pt SA @VP‐Ni 3 P‐MoP heterostructure on nickel foam is presented, demonstrating high catalytic performance. The existence of Pt SA on triphasic metal phosphides gives an outstanding performance toward overall water splitting. The Pt SA @VP‐Ni 3 P‐MoP performs a low overpotential of 28 and 261 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at a current density of 10 and 25 mA cm −2 , respectively. The Pt SA @VP‐Ni 3 P‐MoP (+,−) alkaline electrolyzer achieves a minimum cell voltage of 1.48 V at a current density of 10 mA cm −2 for overall water splitting. Additionally, the electrocatalyst exhibits a substantial Faradaic yield of ≈98.12% for H 2 and 98.47% for O 2 at a current density of 50 mA cm −2 . Consequently, this study establishes a connection for understanding the active role of single metal atoms in substrate configuration for catalytic performance. It also facilitates the successful synthesis of SACs, with a substantial loading on transition metal phosphides and maximal atomic utilization, providing more active sites and, thereby enhancing electrocatalytic activity.