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

[Display omitted] • Heterostructures of the three-dimensional spindle shape were successfully synthesized. • Bimetallic sulfides driven by topological sulfidation of bimetallic MOFs. • DFT reveals electronic coupling at the atomic/orbital level. • Heterogeneous interfaces provide efficient electron tuning engineering. 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 (VS 4) and heptairon octasulfide (Fe 7 S 8) composites have rarely been reported. Here, the facile topological sulfide self-template sacrifice method using FeV bimetallic MOFs is designed to obtain Fe 7 S 8 coupled with VS 4 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 Fe 7 S 8 /VS 4 electrodes possessed excellent performances of η 10 = 53 mV, η 10 = 135 mV and η 10 = 38 mV in a conventional three-electrode configuration in a 1 M KOH, 1 M Na 2 SO 4 , and 0.5 M H 2 SO 4 , 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. [ABSTRACT FROM AUTHOR]