Study On Electrochemical Performance Of Ti/PbO₂?Pb₃O₄?-Heterogeneous Magnetic Granules 2.5 Dimensional Anode

Electrocatalytic oxidation water treatment techniques can be broadly defined as an aqueous phase oxidation methods.Since the electrocatalytic oxidation water treatment technology has the advantages of simple operation,high efficiency and cleanness of the reaction process,it has been widely concerned.Among them,the anode material is the core of the whole technology,which will directly affect the degradation effect of the electrochemical reaction system.Traditional anode materials still face problems that need to be solved,such as limited catalytic area and mass transfer reaction,poor stability,and inconvenient practical applications.A new type of anode structure called 2.5 dimensional anode can effectively compensate for the deficiency of conventional anodes.The 2.5D anode?or electrode?consists of a 2 dimensional main electrode and 3 dimensional auxiliary electrodes by magnetic adsorption.In the electrolysis process,both the main and auxiliary electrodes can play their respective roles and advantages in the anode system,and the auxiliary electrodes effectively expands the actual catalytic area and increases the active sites on the surface of the electrode.Simultaneously,the structure of the magnetic composition greatly enhances the adjustability of the entire structure and the flexibility of the anode system.In this paper,the Ti/PbO₂anode and its derived Ti/Pb₃O₄ anode are the main electrodes,because the lead oxide-based electrodes have good conductivity,long service life and low cost,it is beneficial to maintain the entire 2.5D anode efficient operating for a long time.The Fe₃O₄/Sb-SnO₂ granules and the Fe₃O₄/Pb₃O₄ granules AEs are organically combined with the main electrode by magnetic attraction.Furthermore,the effects of ME,AEs and the loading amount of AEs on the electrochemical performance and organics degradation ability of the 2.5D anode were further studied.Each part of the specific results is as follows:?1?The roll-shaped Ti/PbO₂ was used as the main electrode?ME?,the microscale?larger-scale?Fe₃O₄/Sb-SnO₂ granules were used as the auxiliary electrodes?AEs?,and these two were combined to construct the 2.5D Ti/PbO₂-Fe₃O₄/Sb-SnO₂ anode by magnetic force.The constructed 2.5D anode system not only has good conductivity and stability brought by the Ti/PbO₂,but also has more extra catalytic sites and a larger practical surface area brought by Fe₃O₄/Sb-SnO₂.By adjusting the loading of the AEs,the properties of the entire 2.5D anode system could be gradually changed from PbO₂ to Sb-SnO₂,so as to continuously adjust the properties of the entire anode.In addition,the appropriate AEs loading could increase the electrochemical roughness of the entire anode system,so that the 4 h COD removal rate of the electrode at 10 mA·cm^-2 was 82.84%,and 89.33%at 20mA·cm^-2.The electrochemical oxidation capacity and stability of the entire 2.5D anode system were effectively improved.In addition,the electrode exhibited excellent recyclability and long-term durability.Therefore,the 2.5D anode showed great potential for handling complex and variable wastewater in practical applications.At the same time,the operation mechanism,the role of ME and AEs in the electrochemical oxidation process,and the relationship between the 2.5D anode structure and the electrochemical activity were studied in depth,which provided a theoretical basis for its practical application.?2?The foil Ti/PbO₂ was used as the ME,the micro-scale?smaller scale?Fe₃O₄/Sb-SnO₂ and Fe₃O₄/Pb₃O₄ granules were used as the AEs.The ME and AEs were combined by magnetic force to construct 2.5D Ti/PbO₂-Fe₃O₄/Sb-SnO₂?Fe₃O₄/Pb₃O₄?anode,hence these two 2.5D anode system have a large difference in electrochemical oxidation ability,which further validated and improved the operating mechanism of the 2.5D anode.The effects of the variety and loading amount of the AEs on the electrochemical behavior of the 2.5D anode system and the effect on the degradation of organics were compared.It was found that the introduction of two heteromagnetic magnetic AEs significantly increased the electrochemical roughness of the entire 2.5D anode system compared with the 2D electrode,and increased the surface area of the electrode while increasing the internal surface area of the electrode.The occurrence of organic matter mass transfer reaction.In the process of degrading organic pollutants?Acid red G,Lignin?,when the AEs was Fe₃O₄/Sb-SnO₂,the Sb-SnO₂ active coating could generate a large amount of hydroxyl radicals,which mainly produced electrochemical combustion.When the AEs was Fe₃O₄/Pb₃O₄,the Pb₃O₄ active coating could not release hydroxyl radicals,and the electrochemical conversion reaction mainly occured.Finally,the safety and practical applicability of the 2.5D anode system was ensured by the leaky content test of toxic Pb²⁺.?3?The foil Ti/Pb₃O₄ was used as the ME,the micro-scale?small-scale?Fe₃O₄/Sb-SnO₂ and Fe₃O₄/Pb₃O₄ granules were still used as the AEs,the ME and AEs were combined to construct the 2.5D Ti/Pb₃O₄-Fe₃O₄/Sb-SnO₂?Fe₃O₄/Pb₃O₄?anode by magnetic force.While further exploring the effect of the low oxygen evolution overpotential main electrode on the electrochemical behavior of the2.5D anode system,Pb₃O₄ was also explored the performance of the electrode in chlorinated waters due to its strong chlorine evolution activity.In the process of degrading organic pollutants,the different synergistic effects of ME and AEs of2.5D anode and the degradation rate of acid red G?ARG?on the AEs were investigated under the conditions of chlorine-free/low concentration chlorine/high concentration chlorine.The results showed that under the condition of chlorine-free,the AEs could provide a larger catalytic area and more catalytic active sites for the 2.5D electrode system,which was beneficial to the degradation of ARG.Under chlorine-containing conditions,the active chlorine produced by Pb₃O₄inhibited the oxygen evolution reaction of the electrode and further degraded the ARG by the active chlorine produced.Finally,the operating mechanism of the2.5D anode system in chlorine-containing water was further improved.