Heterometallic Electrocatalysts Derived from High-Nuclearity Metal Clusters for Efficient Overall Water Splitting.

The development of cost-effective electrocatalysts with an optimal surface affinity for intermediates is essential for sustainable hydrogen fuel production, but this remains insufficient. Here we synthesize Ni 2 P/MoS 2 -CoMo 2 S 4 @C heterometallic electrocatalysts based on the high-nuclearity cluster {Co 24 (TC4A) 6 (MoO 4 ) 8 Cl 6 }, in which Ni 2 P nanoparticles were anchored to the surface of the MoS 2 -CoMo 2 S 4 @C nanosheets via strong interfacial interactions. Theoretical calculations revealed that the introduction of Ni 2 P phases induces significant disturbances in the surface electronic configuration of Ni 2 P/MoS 2 -CoMo 2 S 4 @C, resulting in more relaxed d-d orbital electron transfers between the metal atoms. Moreover, continuous electron transport was established by the formation of multiple heterojunction interfaces. The optimized Ni 2 P/MoS 2 -CoMo 2 S 4 @C electrocatalyst exhibited ultralow overpotentials of 198 and 73 mV for oxygen and hydrogen evolution reactions, respectively, in alkaline media, at 10 mA cm -2 . The alkali electrolyzer constructed using Ni 2 P/MoS 2 -CoMo 2 S 4 @C required a cell voltage of only 1.45 V (10 mA cm -2 ) to drive overall water splitting with excellent long-term stability.