In-situ confinement strategy for constructing CoP-NiP2 QDs/NC as an efficient and robust bifunctional electrocatalyst for overall water splitting in a wide pH range

Transition metal phosphides (TMPs) suffer from electrocatalytic activity loss due to particle aggregation. We have proposed a MOF confinement strategy synthesizes CoP-NiP 2 quantum dots (QDs) embedded in N-doped carbon (CoP-NiP 2 QDs/NC), achieving atomic-level dispersion of active species. Electrochemical analyses reveal: 1) hydrogen evolution reaction (HER) performance surpassing commercial 20% Pt/C above 42   mA·cm -2 with ultralow loading (0.2   mg·cm -2 ); 2) Superior oxygen evolution reaction (OER) and overall water splitting in alkaline/neutral electrolytes, outperforming commercial RuO 2 and RuO 2 ||Pt/C electrolytic cell. Enhanced charge transfer kinetics supported by density functional theory (DFT) calculations, which reveal synergistic electronic interactions between CoP and NiP 2 optimizing Gibbs free energy of reactions and water adsorption/dissociation energetics. This work shows a confinement-driven design strategy for multicomponent TMP QDs, bridging synthetic control of compound architectures with their electrocatalytic functionality for efficient hydrogen production.