Creating High‐entropy Single Atoms on Transition Disulfides through Substrate‐induced Redox Dynamics for Efficient Electrocatalytic Hydrogen Evolution

Abstract The controllable anchoring of multiple metal single‐atoms (SAs) into a single support exhibits scientific and technological opportunities, while marrying the concentration‐complex multimetallic SAs and high‐entropy SAs (HESAs) into one SAC system remains a substantial challenge. Here, we present a substrate‐mediated SAs formation strategy to successfully fabricate a library of multimetallic SAs and HESAs on MoS 2 and MoSe 2 supports, which can precisely control the doping location of SAs. Specially, the contents of SAs can continuously increase until the accessible Mo atoms on TMDs carriers are completely replaced by SAs, thus allowing the of much higher metal contents. In‐depth mechanistic study shows that the well‐controlled synthesis of multimetallic SAs and HESAs is realized by controlling the reversible redox reaction occurred on the TMDs/TM ion interface. As a proof‐of‐concept application, a variety of SAs‐TMDs were applied to hydrogen evolution reaction. The optimized HESAs‐TMDs (Pt,Ru,Rh,Pd,Re‐MoSe 2 ) delivers a much higher activity and durability than state of‐the‐art Pt. Thus, our work will broaden the family of single‐atom catalysts and provide a new guideline for the rational design of high‐performance single‐atom catalysts.