Room-temperature air oxidation of organic pollutants via electrocatalysis by nanoscaled Co-CoO on graphite felt anode

Oxygen (O 2 ) in air is an eco-friendly and economical oxidant. However, its activation is an energy-intensive process requiring high operation temperature. Herein, we report the synthesis of nanoscaled Co-CoO on a graphite felt (GF) as an anode material for electrocatalytic wet air oxidation (ECWAO) of water contaminants at room temperature. Such an ECWAO process shows extensive effectiveness in mineralizing a variety of biorefractory organic pollutants. A probe pollutant, bisphenol A (BPA), is rapidly degraded in 180 min with mineralization efficiencies higher than 85% over a wide pH range from 3.0 to 11.0. The Co-CoO/GF electrode exhibits excellent stability in the ECWAO process, without loss of activity and leaching of metal. The ECWAO process is confirmed to be initiated by the electrochemical activation of O 2 through a non-radical pathway. The CoO on the surface of Co nanoparticle is identified as the catalytically active site, at which O 2 molecules are first converted to chemisorbed oxygen species and then electrochemically oxidized to their activated states. The ECWAO process with the Co-CoO/GF electrode presents the merits of high efficiency, low energy input and environmental friendliness, and has a great potential for practical wastewater treatment.