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 Ni2 P/MoS2 -CoMo2 S4 @C heterometallic electrocatalysts based on the high-nuclearity cluster {Co24 (TC4A)6 (MoO4 )8 Cl6 }, in which Ni2 P nanoparticles were anchored to the surface of the MoS2 -CoMo2 S4 @C nanosheets via strong interfacial interactions. Theoretical calculations revealed that the introduction of Ni2 P phases induces significant disturbances in the surface electronic configuration of Ni2 P/MoS2 -CoMo2 S4 @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 Ni2 P/MoS2 -CoMo2 S4 @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 Ni2 P/MoS2 -CoMo2 S4 @C required a cell voltage of only 1.45 V (10 mA cm-2 ) to drive overall water splitting with excellent long-term stability.