Construction Of Novel Cobalt-carbon Dual Reaction Centers Water Purification System And Pollutant Removal Mechanism

An increasing number of emerging contaminants（ECs）have been detected in the natural water environment,causing a serious threat to the ecology and human health.Advanced oxidation processes（AOPs）are a water treatment technology with the potential to remove ECs,but they rely on large amounts of chemical agents and energy input,resulting in high energy consumption and low efficiency.Accordingly,this paper develops a cobalt-carbon dual-reaction-centers（DRCs）water purification system with excellent performance through the orderly regulation of the surface structure of carbon materials and the construction of electron-poor/rich micro-regions to realize the activation of dissolved oxygen（DO）and electron-donation effect of pollutants in water under the induction of PMS and without external energy assistance,respectively,so as to reduce the resource and energy consumption in the water purification process.First,new cobalt-carbon DRCs catalysts（CCM-CMSs）were successfully prepared by coupling graphitization process and cobalt（Co）doping modification step.The structure-activity relationship analysis confirmed the formation of C-O-Co bond bridges on the catalyst surface resulting in cation-Ï€interactions,which caused an unbalanced distribution of electrons on the catalyst surface resulting in electron-poor/rich micro-regions.All types of ECs in the CCM-CMSs/PMS system can be completely degraded in just 2 min and exhibit superb performance in actual wastewater purification.By exploring the interfacial reaction mechanism,we found that during the reaction process PMS acts as an inducer to induce pollutants around the electron-poor center to provide electrons for the reaction throughÏ€-Ï€interactions with the catalyst,and induce DO around the electron-rich center to be activated to produce large amounts of reactive oxygen species（ROS）by receiving electrons and energy provided by the pollutants.The pollutants are rapidly degraded by cleavage on the catalyst surface and attacked by ROS.The above work confirms that it is a feasible strategy to construct cation-Ï€structures on the catalyst surface through ordered surface modulation to induce an unbalanced distribution of electrons on the catalyst surface to form electron-poor/rich micro-regions,which is beneficial to promote the activation of DO and the electron-donation effect of pollutants.To further reduce the resource and energy consumption in water treatment process,we have successfully developed cobalt-iron（Co Fe）quantum dots carbon nanowires DRCs catalysts（Co Fe Qds@GN-Nws）with cation-Ï€structure by anaerobic polymerization technology and used it to construct a water self-purification system.The system can directly utilize the energy of DO and the bond energy of pollutants to achieve the self-purification process of wastewater under natural conditions without external oxidants or external energy.The system showed excellent degradation performance for all types of ECs and showed excellent purification performance for actual industrial dyeing wastewater.The successful construction of the cation-Ï€structure and Co Fe quantum dots structure was confirmed by the structure-activity relationship.The introduction of cobalt and iron led to the polarization distribution of electrons on the catalyst surface and the formation of electron-poor/rich micro-regions.Therefore,Co Fe Qds@GN-Nws can trigger the electron-donating effect of pollutants,causing them to be cleaved/oxidized on the catalyst surface and activating DO to O₂^·-synergistically removing pollutants thus realizing an efficient self-purification process of wastewater.The Co Fe Qds@GN-Nws self-purification system greatly reduces the resource and energy consumption in the water treatment process.