Ti/TiO₂NTs/PbO₂ Electrode Modified By MOF Derived Materials In Electrocatalyzed Organic Wastewater Application

Electrochemical oxidation technology is considered as a promising green,clean,safe and convenient method of organic wastewater treatment.However,the preparation of anode materials with high catalytic activity and low cost hinders the large-scale application of electrochemical oxidation technology.MOF-derived metal or metal oxide carbon composite materials have good electrical conductivity,catalytic activity and good thermal/chemical stability.These excellent properties make it widely used in environmental remediation,energy storage systems and catalysts.This study based on the current PbO₂ electrode has low catalytic activity and low electrode life.The metal oxide carbon composite materials derived from different MOFs are used to improve the electrocatalytic performance of the electrode through surface modification and doping.The degradation process of electrochemical oxidation of aromatic organic pollutants is studied,and the degradation mechanism of different electrode materials on organics is analyzed,which provides a simple method for the synthesis of titanium-based PbO₂ electrodes with high activity and good stability.The main research contents of this paper are as follows:To overcome the shortcoming of Ti/PbO₂,a novel of Ti/TiO₂NTs/NiO@C/PbO₂ electrode was constructed by introducing a 2D Ni-MOF derived NiO@C nanosheet arrays interlayer onto the Ti/TiO₂NTs matrix via hydrothermal and carbonization process.Benefiting from the synergistic effect and the unique nanostructure,the Ti/TiO₂NTs/NiO@C/PbO₂ electrode exhibited outstanding electrochemical activity,higher·OH radicals generating ability and excellent electrocatalytic degradation performance.By introducing TiO₂NTs matrix and 2D Ni-MOF derived NiO@C nanosheet,the Ti/TiO₂NTs/NiO@C/PbO₂ electrode surface grain size decreased,the electrochemical active area and active site number increased,the charge transfer resistance reduced,the electrode stability strengthened as well as·OH free radical generation ability enhanced.The degradation effects of different electrodes on salicylic acid（SA）were compared.The effects of initial concentration,applied current density and pH in the solutions on the electrocatalytic performances for the degradation of SA were also studied in detail.Additionally,the possible electrocatalytic degradation mechanism of the Ti/TiO₂NTs/NiO@C/PbO₂ electrode for SA was proposed,and a possible degradation pathway for SA was speculated by UV-visible absorption spectroscopy and liquid chromatography combined with mass spectrometer（LC-MS）.In this experiment,ZrO₂-C/PbO₂nanocomposite electrodes were fabricated on Ti/TiO₂NTs substrate by co-deposition technique in the lead nitrate plating bath doped with UiO-66 derived ZrO₂-C nanoparticles have porous structure,excellent adsorption performance,catalytic activity and high electrical conductivity,which could coordinate PbO₂to effectively eliminate 2,4,6-trinitrophenols（TNP）through electrochemical oxidation.The experimental results show that the ZrO₂-C nanoparticles added to lead dioxide in tuning the morphology become denser,more homogeneous,and the grain size smaller.When exploring the doping amount of different ZrO₂-C nanoparticles,the electrochemical performance test proves that the optimal doping amount of ZrO₂-C nanoparticles is 0.4 g L^-1.Compared with other PbO₂ electrode,the(0.4 g L^-1)ZrO₂-C/PbO₂anode shows the most number of surface active sites,superior·OH radicals generation,highest conductivity,and the accelerated life is about 2.6 times that of the pure PbO₂ electrode.The electrochemical treatment of organic wastewater showed that the removal ratio of TNP(20 mg L^-1)on(0.4 g L^-1)ZrO₂-C/PbO₂ electrode reached 94.48%after electrolysis for 140 min,while the removal rate was only 68.33%at pure PbO₂ electrode.Further the influence of the applied current density,the initial concentration of TNP and initial pH value on the TNP and TOC removal ratio were also optimized.Additionally the electrochemical degradation pathway of TNP was also proposed based on the UV-visible absorption spectroscopy and the liquid chromatography-mass spectrometry analysis.Thus,these findings proved that MOF derived material-doped PbO₂ anodes electrocatalytic degradation of refractory organic pollutants,which have greater promising application potential.Figure 25 Table 9 Reference 121...