Electrodeposition of pore-confined cobalt in metal–organic framework thin films toward electrochemical H2O2 detection

Abstract

In this study, cobalt is electrodeposited within solvothermally grown thin films of a zirconium-based metal–organic framework, MOF-808, to obtain electrochemically active cobalt confined in the pore of MOF-808 crystals. With the help of the highly porous but electrically insulating MOF-808 thin film and a step-wise electrodepositing technique, cobalt can be mainly deposited within the pore of MOF-808 crystals. The resulting Co@MOF-808 thin film is applied for electrochemical H2O2 sensor in aqueous electrolytes, and its electrocatalytic activity toward H2O2 significantly outperforms that of the electrodeposited cobalt on a bare substrate. The electrochemical behavior of Co@MOF-808 thin films and the corresponding electrocatalytic mechanism toward H2O2 are investigated. The material is further used for amperometric H2O2 detection, and a sensitivity, limit of detection, and linear range of 382.27 μA/mM-cm2, 1.3 μM, and 10–450 μM can be achieved, respectively.