Cooperative Boron and Vanadium Doping of Nickel Phosphides for Hydrogen Evolution in Alkaline and AnionExchange Membrane Water/Seawater Electrolyzers

Developing low-cost and high-performance transition metal-based electro-catalysts is crucial for realizing sustainable hydrogen evolution reaction (HER)in alkaline media. Here, a cooperative boron and vanadium co-doped nickelphosphide electrode (B, V-Ni2P) is developed to regulate the intrinsic elec-tronic configuration of Ni2P and promote HER processes. Experimental andtheoretical results reveal that V dopants in B, V-Ni2P greatly facilitate the dis-sociation of water, and the synergistic effect of B and V dopants promotes thesubsequent desorption of the adsorbed hydrogen intermediates. Benefitingfrom the cooperativity of both dopants, the B, V-Ni2P electrocatalyst requires alow overpotential of 148 mV to attain a current density of −100 mA cm−2 withexcellent durability. The B, V-Ni2P is applied as the cathode in both alkalinewater electrolyzers (AWEs) and anion exchange membrane water electrolyzers(AEMWEs). Remarkably, the AEMWE delivers a stable performance to achieve500 and 1000 mA cm−2 current densities at a cell voltage of 1.78 and 1.92 V,respectively. Furthermore, the developed AWEs and AEMWEs also demon-strate excellent performance for overall seawater electrolysis.