Unraveling the Role of Functional Groups of Terephthalate in Enhancing the Electrochemical Oxygen Evolution Reaction of Nickel–Organic Framework Nanoarrays

The platelike nickel-terephthalate-type metal–organic framework nanoarrays (Ni-BDC NAs) on carbon cloth are obtained by employing agaric-like Ni(OH)₂ NAs as sacrificial templates. The microenvironment of Ni-BDC NAs is modulated by various neighboring functional groups (−NH₂, −NO₂, and −Br) on the carboxylate ligand, exerting minimal destructive effects on the structure and morphology of Ni-BDC NAs. The electrochemical oxygen evolution reaction (OER) of Ni-BDC–NH₂ NAs, Ni-BDC–NO₂ NAs, and Ni-BDC–Br NAs exhibited a significant enhancement compared to that of Ni-BDC NAs alone, as evidenced by both experimental and theoretical assessments. The presence of neighboring groups exerts a positive influence on the electronic coupling between Ni and O atoms, thereby facilitating the thermodynamically favorable formation of *O intermediates on Ni sites and accelerating the kinetics of the OER. The findings presented here provide valuable insights for the design and utilization of carboxylic acid molecules with functional group effects, enhancing the activity of the OER across diverse Ni centers.