Distance Synergy of MoS2‐Confined Rhodium Atoms for Highly Efficient Hydrogen Evolution

Abstract Perturbing the electronic structure of the MoS 2 basal plane by confining heteroatoms offers the opportunity to trigger in‐plane activity for the hydrogen evolution reaction (HER). The key challenge consists of inducing the optimum HER activity by controlling the type and distribution of confined atoms. A distance synergy of MoS 2 ‐confined single‐atom rhodium is presented, leading to an ultra‐high HER activity at the in‐plane S sites adjacent to the rhodium. By optimizing the distance between the confined Rh atoms, an ultra‐low overpotential of 67 mV is achieved at a current density of 10 mA cm −2 in acidic solution. Experiments and first‐principles calculations demonstrate a unique distance synergy between the confined rhodium atoms in tuning the reactivity of neighboring in‐plane S atoms, which presents a volcanic trend with the inter‐rhodium distance. This study provides a new strategy to tailor the activity of MoS 2 surface via modulating the distance between confined single atoms.