Surface Coordination Chemistry of Two-Dimensional Materials: From Fundamental Coordination Concepts to Local Electrochemical Activity

Transition metal dichalcogenides (TMDs) are promising materials for electronics and electrocatalysis, but conventional doping methods often introduce structural defects that degrade their properties. Here, we demonstrate that surface coordination chemistry provides a non-destructive strategy to tailor the electronic and electrochemical properties of MoS₂ through the coordination of isolated transition metal atoms. Density functional theory shows that metal–MoS₂ interactions follow classical coordination chemistry principles, where crystal-field stabilization energy and Lewis acid–base interactions govern metal–sulfur bonding and charge transfer. HAADF-STEM, XPS, photoluminescence, Kelvin probe microscopy, and scanning electrochemical cell microscopy confirm the formation of atomically dispersed coordination complexes and validate the predicted doping behavior. Au and Ti induce p-type doping, whereas Ni produces n-type doping through stronger covalent metal–sulfur interactions. These electronic modifications directly control the local hydrogen evolution reaction activity, with Ti-functionalized MoS₂ showing enhanced performance and Ni-functionalized samples reduced activity, demonstrating surface coordination chemistry as strategy for TMDs doping.