Study On Deactivation And Synergy Of Dimensional Stability Anode At Low Temperature Environment

In order to protect the marine ecological environment and prevent foreign marine species from causing damage to our country’s marine ecological environment,sailing ships can’t directly discharge ballast water containing a large number of microorganisms into the offshore area.The microorganisms in the ballast water need to be inactivated to achieve the specified emission standards.One of the most commonly used treatment technologies is electrocatalysis,the principle of which is to use metal oxide anodes to electrolyze seawater to produce effective chlorine,thereby killing microorganisms in ballast water.A problem encountered with the current technology is that the chlorine evolution activity of the oxide anode iss not high and deactivation is relatively fast at low temperature.In this academic dissertation,the electrocatalytic performance of the Ru-Ir-Sn series metal oxide anodes at different temperatures was evaluated and the mechanism of electrode deactivation was analyzed.It was found that the chlorine evolution activity of the electrode was greatly reduced at low temperature,especially when the temperature reached 5℃.The efficiency of chlorine evolution decreased significantly from 86.7%at 25℃to64.8%,and the enhanced electrolysis life shortened from 75h to 50h.Through physical characterization analysis of the inactivated electrode,the reason of anodes deactivation at low temperature was the peeling of the surface coating.In order to solve the problem,the optimization of the organic coating solution was optimized.The different nanometer sizes graphene and graphene oxide were selected and doped into the organic coating solution to obtain the composite modified oxide anodes.It showed that the chlorine evolution activity of the composite modified oxide anodes was improved at low temperature environment,and the service life was prolonged.Among them,the graphene quantum dot composite modified anodes had the highest chlorine evolution activity,and the service life can reach more than 100h.The graphene quantum dot with different concentrations were selected for modification research.The results showed that when the addition concentration was 0.4g/L,the modified oxide anodes had the highest chlorine evolution activity at low temperature.Based on the first-principle calculation method and the theoretical framework of density function theory,the electronic structure of Ru_0.2Ir_0.2Sn_0.6O₂ was calculated and the reaction processes of chlorine evolution and oxygen evolution were analyzed.Results showed that the Ru_0.2Ir_0.2Sn_0.6O₂ oxide anodes possessed suitable Cl adsorption energy.