Hollow Tubular Engineering and Electronic Structure Modulation of Vanadium-Incorporated MoP for Boosting Alkaline Hydrogen Evolution

Synergistically optimizing electronic structure and exposing abundant active sites is a promising route to enhance electrocatalytic activity, yet remains challenging. Herein, a hierarchical tubular structure of vanadium-incorporated molybdenum phosphide (V-MoP) was successfully constructed for highly effectively alkaline hydrogen evolution. Molecular self-assembly of a V-substituted Keggin-type polyoxometalate (POM) with a simple organic ligand was exploited to induce a hollow tubular precursor and trigger precise V doping by virtue of the intrinsic structural features of POMs, thereby realizing simultaneous morphology engineering and electronic structure modulation. The unique open-ended hollow tubular structure, which furnishes both internal and external surfaces and superhydrophilicity, increases the exposure of electrochemical active sites, promotes rapid electrolyte penetration and shortens mass transfer pathways. Moreover, V doping effectively modulates the electronic structure of MoP, further renders Mo and P sites more electron-rich, meanwhile triggering the coexistence of V3+ and V5+, which further promotes water dissociation and hydrogen evolution. Consequently, the V-MoP catalyst exhibits significantly enhanced activity, far beyond that of pristine bulk MoP and bulk V-MoP, and even surpasses that of commercial 20% Pt/C at high current densities. This work provides a feasible strategy for designing advanced electrocatalysts with tailored morphology and tunable electronic structures.