Atomic-level chelation engineered Ni-salicylate MOFs with hierarchical nanobelt assemblies for selective glucose electrooxidation

Abstract

By employing a salicylate coordination strategy to precisely modulate the microenvironment of nickel active sites, a hierarchically porous nickel salicylate (Ni-SA) metal-organic framework (MOF) was constructed for efficient electrocatalytic glucose oxidation. The ortho-hydroxy-carboxylate chelation directs the atomic-level organization of Ni²⁺ sites within nanobelt assemblies, thereby maximizing active site accessibility. Robust Ni–O coordination further stabilized Ni³⁺ intermediates during C–H bond cleavage, leading to remarkable catalytic stability. As a result, the optimized Ni-SA-2 catalyst achieved outstanding sensing performance, with a high sensitivity of 5.97 mA mM⁻¹ cm⁻² and a low detection limit of 0.71 µM (signal-to-noise ratio (S/N) = 3), alongside 85.4% current retention after 8 h continuous operation. Significantly, this design paradigm demonstrates universal applicability as evidenced by successful extension to isostructural M-SA analogs (M = Co, Fe, Cr, Mn) under identical synthetic conditions, ultimately establishing metal-salicylate frameworks as a versatile electrocatalyst platform.