Facile Synthesis of Fe-MOF/rGO nanocomposite as an Efficient Electrocatalyst for Nonenzymatic H2O2 Sensing

Abstract

An Fe-MOF (metal-organic framework)/reduce graphene oxide (rGO) nanocomposite was formed by using an efficient synthetic method. The morphology and structure of the Fe-MOF/rGO nanocomposite were characterized by scanning electron spectroscopy (SEM) and X-ray diffraction (XRD). The Fe- MOF/rGO nanocomposites were immobilized on a carbon paste electrode (CPE) to construct a highperformance nonenzymatic electrochemical H2O2 sensor. A cyclic voltammetry (CV) study showed that the Fe-MOF/rGO nanocomposites displayed better electrocatalytic activity toward H2O2 reduction compared to that of Fe-MOF. An amperometric study indicated that the H2O2 sensor displayed high performance, which offered a low detection limit (0.5 μM), a high sensitivity (5.17 pA mM-1 cm-2), and a wide linear range (from 5.0 to 945 pM). An electrochemical reaction mechanism was proposed for H2O2 reduction on the Fe-MOF/rGO/CPE. Importantly, the as-fabricated H2O2 sensor exhibited good reproducibility and excellent selectivity. Furthermore, the constructed high-performance sensor was utilized to monitor the H2O2 levels in real samples, and satisfactory results were obtained. These results demonstrated that the Fe-MOF/rGO nanocomposite can be used as a good electrochemical sensor material in practical applications.