Synthesis and characterization of Ni0.3Co2.7O4 oxide nanoparticles immobilized in Teflon cavity electrode for organic pollutants degradation

A simple cost effective sol-gel process for the nickel cobaltite oxide production using sulfate precursors and citric acid as chelating agent is reported. The obtained nanopowders were characterized, immobilized in teflon cavity electrode to investigate their catalytic properties, using ethylene glycol and methylene blue as contaminants models in various conditions. The electrode stability and reutilization have also been discussed. Spinel Ni0.3Co2.7O4 nanocristallites of about 11 nm with regular cauliflower-like shape agglomeration and high surface area equals 49 m(2).g(-1) and having mesoporous structure, were obtained. This oxide displays two absorption transitions at 1.61 and 3.26 eV, besides; it can be stored for long-terms since its preparation. The formed electrode exhibits excellent electrochemical stability with sufficient charge transfer kinetics and a large accessible mesoporous surface area. Furthermore this electrode is powerful to remove both pollutants, by pseudo-first order mechanism, without significant adsorption and can be used again for several cycles. Indeed, it was found that the photoelectrocatalytic process is more efficient than photocatalytic or electrocatalytic oxidation alone, indicating the light synergistic effect combined with the applied potential. Low cost, simple preparation, long-term storage, operational stability and ability to degrade organics can make this electrode a candidate for industrial use.