Preparation And Properties Research Of Modified Muiti-Components Electrode Coating On Ti Base With Interlayer Adding

The increasingly serious environmental pollution and resource depletion are two major issues that affects human survival and development. The effective ways for sustainable development are resources recycling and turning waste into treasure. With mass production of PCB board, the environmental pollution and resources waste of acid etching waste attracted extensive attention. The electrolytic regeneration of acid etching waste not only can recover metallic copper also can regenerate the etching solutions. Recycling resources and governing contaminants simultaneously. However, the selection of electrode is the core issue in electrolysis process whose electrochemical reactions occur at the interface between the electrode surface and electrolyte. The emergence of DSA electrodes greatly promoted the development of electrode materials. According to different needs of electrodes,researchers prepared chlorine evolution or oxygen evolution electrodes by modifying or adding different active ingredients of coatings.To address the problems of easily producing chlorine gas and short-lived of electrode in the electrolytic recovery process of acid etching solution, contained intermediate layer TNTs/Ir O2-Ta2O5-SnO2-Sb2O5-MnO2 anode was prepared by modifying electrode, adding the intermediate layer and optimizing the preparation of multi-components coating which appropriately improve the electrocatalytic activity, chlorine evolution potential and service life. First, using the anodic oxidation-thermal decomposition method to prepare TNTs/IrO₂-Ta₂O₅-SnO₂-Sb₂O₅-MnO₂ anodes with three different molar ratios of the coating liquid. Through characterization methods such as the SEM, EDS, XRD, electrochemical testing, accelerated life testing to investigate the influence on the morphology, structure, electro-catalytic properties, oxygen evolution potential, chlorine evolution potential and life of anodes in different molar ratio of the coating liquid. Research found out that the multiple active coatings electrode prepared by coating liquid with metal molar ratio of Ir: Ta: Sn: Sb: Mn = 15: 5: 60: 10: 10 exists in the form of a solid solution, and the electrode has higher catalytic activity, porosity, oxygen evolution potential and chlorine evolution. Especially the electrode under the condition of 1Acm-2 current density,accelerate life time extend to 850 h which is the longest. The deactivate mechanism of TNTs/IrO₂-Ta₂O₅-SnO₂-Sb₂O₅-MnO₂ electrode concluded that the main reasons were the dissolution and flaking of active coating and the form of high conductive TiO2 between the base and the oxide layer.On the basis of successfully prepared active coating, we added Ir-Ta oxide as an intermediate layer to investigate the effect on the electrochemical performance and service life. Optimize the Ir/Ta molar ratio of the intermediate layer and test the intermediate layers performance by physical and electrochemical characterization. It obtained that the intermediate layer with Ir/Ta molar ratio of 8:2 has the highest electro-catalytic activity and porosity. The accelerate life test under 1Acm-2 current density shows that the life of active coating anode containing intermediate layer can reach to1260 h, which improve the stability of the electrode and effectively prevents the passivation of titanium-based.To explore the intermediate layer further, on the basis of Ir-Ta-based intermediate layer, Sn, Mn were added to prepare IrO2-Ta2O5-SnO2, Ir O2-Ta2O5-MnO2, IrO2-Ta2O5-SnO2-MnO2 intermediate layers. It turn out that the prepared IrO2-Ta2O5-SnO2 intermediate layer combined tighter, surface roughening, and improved the mechanical binding force between the substrate and active layer. Relative to the electrode coating containing Ir-Ta oxide interlayer,The interlayer which added SnO2 and MnO2 weakened the service life of electrode, but helped to improve the electrocatalytic activity of intermediate layer and reduce production cost.