Polarizable Vanadium Dipoles Promote Water Dissociation on Vanadium‐Based Metal Organic Framework

ABSTRACT Understanding the link between local electronic structure and water dissociation is important for making good working, pH‐universal electrocatalysts. Here, we describe phosphorus‐added vanadium‐containing metal‐organic framework (P@V‐MOF) nanosheets that show great hydrogen evolution activity in acid, neutral, and alkaline solutions. Using BOLS‐NEP theory, XPS, PRS, XAS, and DFT calculations, we show that P atoms create V─P─C bonding, make V─O bonds longer, and cause antibonding V δ + dipoles, which moves the V 3d‐band center closer to the Fermi level. The polarization of unpaired V 3d electrons help V δ + :O─H hydrogen bond formation to weaken the H─O bonds in water, which lowers the water dissociation and * H adsorption energy. P@V‐MOF electrocatalyst shows low overpotentials (94 mV in acid, 178 mV in neutral, and 77 mV in alkaline solutions) and good stability for overall water splitting (1.53 V at 10 mA cm −2 ). These findings show the importance of hetero‐coordination and dipolar coupling to activite water molecules and develop effective, non‐noble‐metal electrocatalysts.