Atomic-scale interfacial engineering enables high-performance electrochemical glucose detection

Abstract

Developing noble-metal free electrocatalysts with high sensitivity is critical for the large-scale application of electrochemical glucose sensors. This work reports an atomic-scale interfacial engineering strategy to construct highly-active electrocatalyst for glucose detection. Ni(OH)2 nanosheets are decorated with an ultra-thin layer of Co9S8 using the atomic layer deposition (ALD) technique. After in-situ reconstruction, we obtain Ni@Co heterostructure composed of Ni hydroxide nanosheets and CoOx clusters, which exhibits outstanding electrochemical glucose sensing performance. Combining synchrotron-based X-ray adsorption spectroscopy, in situ Raman Spectroscopy, intermittent electrochemical measurements and density functional theory (DFT) calculations, we find that the presence of surface CoOx not only lowers the valence state of Ni, but also facilitates the deprotonation of Ni(OH)2 to form NiOOH active species for glucose oxidation. The approach used in this work can be adapted to synthesizing high-performance electrocatalysts for other energy and environmental devices.