Highly dispersed Pt nanoparticles decorated carbon nanocomposite (Pt20/C80) for sensitive nonenzymatic glucose determination and formic acid oxidation

A Pt₂₀/C₈₀ nanocomposite was synthesized by maintaining Pt content at 20% on an activated carbon support (80%), resulting in excellent Pt nanoparticles dispersion and catalytic performance towards direct electro-oxidation of glucose and formic acid. The compositional, structural and morphological characterization of Pt₂₀/C₈₀ were examined using transmission electron microscopy (TEM), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry was employed in order to confirm the both, typical metallic electrochemical response and formic acid oxidation studies. Hydrodynamic amperometry was employed for direct glucose determination. The aim of the study was to improve the sensitivity and catalytic response by effective Pt surface utilisation and dispersion on carbon supporting matrix. Pt₂₀/C₈₀ resulted in excellent sensitivity (21.4 μAmM^-1cm^-2 at E_app = 0.4 V vs Ag/AgCl) towards glucose sensing, over the range 0-10 mM in neutral conditions (pH 7.4). Results demonstrated the effective utility of precious Pt and strong capability for nonenzymatic glucose detection, while eliminating the pH, temperature sensitivity and lifetime issues associated with enzyme based glucose systems. The composite material was also tested for formic acid oxidation (0.5 M H₂SO₄ + 0.5 M HCOOH) and studies revealed its strong potential for direct formic acid fuel cell applications.