Investigation of Doping Effects on the Local Electrochemical Activity of Transition Metal Dichalcogenides 2D Materials

Abstract Finding strategies to enhance catalysts’ electrochemical activity is based on controlling the material design. Bidimensional materials (2DM) such as MoS₂ are explored as catalysts for the hydrogen evolution reaction (HER). A comprehensive study of the effects of doping 2D materials with transition metals based on theoretical predictions in tandem with experimental investigation correlates the doping type to the changes in the electronic and electrochemical activity. Localized electrochemical maps obtained by scanning electrochemical cell microscopy (SECCM) reveal that Ti‐doping induces a heterogeneous increase in 2H‐MoS₂ basal plane electrochemical activity, while Ni‐doping induces a homogeneous decrease. Additionally, Kelvin probe microscopy provides insight into Ti‐doping, showcasing a decline in the 2H‐MoS₂ work function, therefore confirming the predictions from density functional theory simulations. In essence, the findings underscore the potential of transition metal coordination on the 2H‐MoS₂ surface as an attractive method for locally doping 2D materials with minimal damage to the crystalline lattice, consequently enhancing the electrochemical activity on the material's basal plane.