Fe₇S₈ coupled with VS₄ heterogeneous interface engineering driven by FeV bimetallic MOFs: An efficient all-pH and...

Rational design and preparation of a multiphase electrocatalyst for hydrogen evolution reaction (HER) has become a hot research topic, while applicable and pH versatility of vanadium tetrasulfide (VS₄) and heptairon octasulfide (Fe₇S₈) composites have rarely been reported. Here, the facile topological sulfide self-template sacrifice method using FeV bimetallic MOFs is designed to obtain Fe₇S₈ coupled with VS₄ heterostructures, enhancing the electron precipitation in the catalysts and attracts electrons to migrate. According to DFT simulations, the electronic coupling at the atomic orbital level and the modulation of interfacial electrons among various interfaces play a crucial role in enhancing the intermediate state process of the hydrogen evolution reaction (HER) across the entire pH range, promoting the optimal d-band centroid value (ε_d). Reassuringly, the prepared 3D Fe₇S₈/VS₄ electrodes possessed excellent performances of η₁₀ = 53 mV, η₁₀ = 135 mV and η₁₀ = 38 mV in a conventional three-electrode configuration in a 1 M KOH, 1 M Na₂SO₄, and 0.5 M H₂SO₄, and the stabilized currents can all be maintained for 48 h. This innovative design of in situ heterostructured materials constructed from dual transition metal sulfides provides inspiring ideas for the preparation of all-pH catalysts.