Co-Based Transition Metal Hydroxide Nanosheet Arrays on Carbon Cloth for Sensing Glucose and Formaldehyde

Defect engineering has become an effective way to improve the surface performance of nanoelectrochemical catalysts. In this article, the ultrathin defect-rich Co(OH)2 nanosheet arrays in situ grew on carbon cloth (U-D-Co(OH)2 NSA/CC), which was synthesized by etching a metal–organic framework at room temperature. The physical and chemical properties of the obtained U-D-Co(OH)2 NSA were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. It is an efficient electrode for detecting glucose and formaldehyde under alkaline conditions. As a glucose and formaldehyde sensor, it exhibited superior electrocatalytic activity, for instance, shorter response time (<5 s), limit of detection (LOD) of 0.32 μM and 0.57 μM (S/N = 3), and response sensitivity of 6759.0 μA mM–1 cm–2 for glucose and 2444.0 μA mM–1 cm–2 for formaldehyde with outstanding reproducibility and selectivity, respectively.