Bioelectrocatalytic Carbon Ceramic Gas Electrode for Reduction of Dioxygen and Its Application in a Zinc–Dioxygen Cell

An enzyme‐modified carbon ceramic electrode was constructed and studied that is capable to reduce dioxygen supplied from the gas phase. The permeation of the electrode material and its hydrophobic silicate component was studied by scanning electrochemical microscopy. The mass‐transfer coefficient of dioxygen in methyltrimethoxysilane‐based silicate was estimated to be 6.44 × 10^–5 cm² s^–1. After modification of the electrode with bilirubin oxidase and immersion in deareated aqueous electrolyte, the dioxygen bioelectrocatalytic reduction is observed with onset potential at 0.45 V. The constructed electrode was successfully applied as cathode in a zinc–dioxygen cell.