Improved non-enzymatic H2O2 sensors using highly electroactive cobalt hexacyanoferrate nanostructures prepared through EDTA chelation route

Over the last decade, there have been increasing reports on novel synthesis approaches for nanostructured hexacyanoferrate materials due to their potential usage in a broad range of electrochemical applications. This study demonstrates a method for synthesis of Cobalt Hexacyanoferrate (CoHCF) nanostructures with controlled size, shape, and structure by nucleation rate control using the Ethylenediaminetetraacetic Acid (EDTA) chelation strategy. The differences in chemical and electronic structures of CoHCF nanostructures achieved through variation of EDTA solution pH were confirmed by characterization. The study demonstrated the role of material synthesis in achieving physical characteristics that led to improved electrochemical activity and charge transfer ability of CoHCF compounds. An increase in electroactive sites and access to those sites because of enhanced specific surface area and pore volume contributed to the superior electrochemical characteristics of the material. Sensors prepared with the synthesized CoHCF nanostructured materials showed much better amperometric sensing ability of H2O2 as compared to previously reported non-enzymatic sensors with similar materials.