Sol-gel-derived α2-K7P2W17VO62/graphite/organoceramic composite as the electrode material for a renewable amperometric hydrogen peroxide sensor

The conductive α2-K7P2W17VO62/graphite/organoceramic composite was prepared by dispersing α2-K7P2W17VO62 and graphite powder in a propyltrimethoxysilane-based sol-gel solution; it was used as the electrode material for an amperometric hydrogen peroxide sensor. The modified electrode had a homogeneous mirror-like surface and showed well defined cyclic voltammograms. Square-wave voltammetry was employed to study the pH-dependent electrochemical behavior of α2-K7P2W17VO62 doped in the graphite organoceramic matrix, and the experiment showed that both protons and sodium cations participated in the redox process. A hydrodynamic voltammetric experiment was performed to characterize the electrode as an amperometric sensor for the determination of hydrogen peroxide. The sensor can be renewed easily in a repeatable manner by a mechanical polishing step and has a long operational lifetime.