Engineering 1T‐MoS 2 ‐Integrated Bimetallic Sulfide Heterostructure on Nickel Foam for Enhanced Alkaline Water/Seawater Splitting

The heterostructured 1T‐MoS 2 ‐based bimetallic sulfides are promising bifunctional electrocatalysts for alkaline overall water splitting. However, the controllable synthesis of these catalysts is hindered by the ready conversion of Mo species to 2H‐MoS 2 and the tedious heterostructure engineering during sulfidation. This work integrates the strategies of heterostructure construction and phase structural control to fabricate a hierarchical Ni 3 S 2 /1T‐MoS 2 heterostructure on Ni foam (Ni 3 S 2 /1T‐MoS 2 @NF) via hydrazine hydrate‐assisted one‐step sulfidation of NiMoO 4 . The intrinsically conductive 1T‐MoS 2 lowers the kinetic barrier for hydrogen adsorption/desorption and promotes the intrinsic HER activity. Meanwhile, the in situ reconstruction of Ni 3 S 2 into NiOOH during catalysis drives the OER activity, whereas Mo species optimize the catalyst architecture to maximize the exposure of active Ni‐based sites. Additionally, the hierarchical architecture with abundant heterojunctions generates extra active sites and preserves the structural integrity. The as‐formed Ni 3 S 2 /1T‐MoS 2 @NF achieves HER and OER overpotentials of 49 and 145 mV at 10 mA cm −2 in 1.0 M KOH, and the electrolyzer requires only 1.49 and 1.52 V to reach 10 mA cm −2 in 1.0 M KOH and real seawater, respectively. This study provides a viable strategy for 1T‐MoS 2 ‐based heterostructures and valuable insights into overall water splitting.