| Titanium-based iridium tantalum oxide anodes have attracted much attention in wastewater treatment,soil remediation and other fields due to their excellent electrochemical activity and stability.One of the development directions of this kind of anode is to prepare the oxide anode presenting better electro-catalytic activity and longer service life with high ratio of performance/cost.As a new surface modification method,plasma treatment technology has exhibited outstanding advantages in the unconventional preparation,surface modification,vacancies and manufacturing defects of nano-catalytic materials,so it can be applied in the preparation of catalyst.The purpose of this study is to prepare IrOx-Ta2O5/Ti electrode materials via radiofrequency(RF)-driven plasma rapid annealing(PRA)process,so as to increase the electrochemical active surface area of the anode and improve the performance of the anode.The main contents are:(1)A 2.0 MHz plasma jet was applied to the preparation of the precursor-brushed IrOx-Ta2O5/Ti anode coating and compared with the traditional IrOx-Ta2O5/Ti anode prepared by conventional thermal decomposition(CTD)method.After characterization and testing,it was found that the surface morphology and properties of the coating changed with the plasma preparation technology.The sponge like microstructure of the coating surface made the electrochemical active area of the PRA anode higher than that of the CTD anode,the PRA sample showed lower overpotential(j=10 mA/cm2)of 233 mV(vs.RHE)and higher voltammetric charges(741.36 mC/cm2),but its accelerated life is general and its stability is not outstanding.Nevertheless,the plasma-assisted process was still a new method for the preparation of metal oxide anode.(2)In order to improve the instability of the metal oxide anode prepared by plasma process,the IrOx-Ta2O5/Ti anode was prepared by PRA treatment+further thermal annealing The dispersibility of the active components and the electrocatalytic activity of oxygen evolution in those anodes prepared by this method were decreased,but its stability was significantly improved.It was worth noting that at the same annealing temperature,the sample(PRA480)prepared by PRA treatment+further thermal annealing method not only has better electrocatalytic performance but also maintained considerable stability compared with CTD anode.This study provided a new idea for the preparation of metal oxide electrode with high electrocatalytic activity and high stability.(3)The above anodes were used for electrocatalytic oxidation of Congo Red(CR)dye wastewater.The concentration changes of the wastewater before and after treatment were detected by UV-VIS Spectrometer,and the degradation kinetic parameters of Congo red solution were analyzed.The results show that the PRA-treated samples had a higher number of electrochemical activities,which enhanced the anode's ability to degrade organic pollutants in dye wastewater.When the electrolysis time was 120min,the PRA anode has the best degradation effect on CR dye wastewater,with the removal rate up to 91.25%and the degradation kinetic rate up to 0.01946 min-1. |
PDF Full Text Request