Solar Multifield-Driven Hybrid Chemical System for Purification of Organic Wastewater Focused on a Nano-Carbon/TiO2/Ti Central Electrode

In this paper, we constructed a synergistic combination of the solar multifield, including the primary photo-field, sub-thermo-field, and sub-electro-field, and then utilized the device for the oxidation of aqueous organic pollutants via multifield-driven thermo-photo-electrochemistry that was focused on a central electrode. The electrode was fabricated using molten carbonate deposition of carbon nanotubes onto TiO2 nanotubes, which were grown in situ on a Ti substrate. The oxidation of aqueous organic pollutants observed by full mineralization of nitrobenzene, driven by a synergistic combination of the solar multifield, was investigated through theory and experiment to determine the mechanism of the onefield, two-field, and three-field coupled patterns. The results indicated that the threefield pattern and system achieved greater oxidation efficiency compared to the one- or two-field patterns. Motivated by a single electro-field, the efficiency was enhanced to 3.6%, and for the application of the solar three-field-driven pattern, the efficiencies were enhanced to 84.9%. By adjusting the solar multifield process, organic pollutants were efficiently oxidized at the surface of a nano carbon/TiO2/Ti central electrode with synergies gained from the photoactivity, heat activation, and being electrically driven. The synergistic effect of the multifield-driven thermo-photo-electrochemistry was found to boost both solar utilization and organic pollutant degradation at the central electrode.