Design Of Novel Faradaic Electrode And Its Application In Capacitive Desalination And Antibiotic Resistant Genes Removal

With the growth of population and rapid development of economy,the contradiction between the increasing demand for water and the shortage of fresh water resources has become more prominent.Supply of freshwater resources has become a global problem.Besides,the appearance of emerging pollutants,such as antibiotic resistance genes（ARGs）,makes water pollution complex and diversified.The safety of drinking water is facing unprecedented challenges.Therefore,this study aimed at the development of high-efficiency and low-energy desalination technology and ARGs pollution control technology.Strategies,such as confinement derivation,construction of doping defects,carbon coating,were applied to design efficient and stable faradic capacitive deionization electrode.The problems of the transport of electrons and ions,enrichment and inactivation of ARGs,as well as the cyclic desalination stability of the electrode were solved.The simultaneous removal of ARGs and Na Cl under combined pollution system was realized.The main research contents and conclusions were as follows:（1）Study on the desalination performance of MOF derived carbon coated Bi nanoparticle electrode:With the carbon coating strategy and low-temperature oxidation-electrochemical reduction strategy,MOF derived carbon nanorod coated Bi nanoparticle electrode was constructed.Owing to the confinement effect of porous carbon nanorods,abundant crystal facets and valence state of Bi,the electrode exhibited high specific capacitance,surface-control proportion,and lower internal resistance and ions transport resistance.The electrode demonstrated excellent desalination capacity(73.20 mg g^-1)and desalination rate(2.36 mg g^-1 min^-1)at 30m A g^-1.In addition,owing to the reserved space for volume expansion,after 100cycles,the adsorption and desorption capacity of the electrode were stable at 83.33%of the initial capacity.And the adsorption and desorption rate maintained at 98.07%and 92.44%of the initial rate,respectively.The electrode exhibited superior desalination performance and desalination cyclic stability in conversion-based materials.（2）Study on the desalination performance of N-doped Mo2Ti C2 MXene membrane electrode:N-doped Mo2Ti C2 MXene self-supporting electrode electrode was constructed by ammonia annealing,and the location of nitrogen doped defects was adjusted by the variation of annealing temperature.The introduction of N-doping defects provided more adsorption sites for ion storage,and reduced the charge transfer resistance of the membrane electrode.The above properties improved the desalination rate and reduced the energy consumption significantly.Under the constant voltage of1.8 V,the desalination capacity and the desalination rate of the membrane electrode was as high as 100.1 mg g^-1 and 5.5 mg g^-1 min^-1,respectively.Besides,the energy consumption was only 0.16 k W h kg^-1.In addition,owing to the stable structure of Mo2Ti C2 membrane electrode,the adsorption and desorption rate of the electrode could still maintain at the 97.6%and 94.9%of the initial rate,respectively,proving the excellent cycle stability of the electrode.（3）Study on desalination and ARGs removal performance of MXene derived ultra-thin Ti O2@graphene aerogel:the ultra-thin Ti O2 nanosheets@graphene aerogel（photo）electrode was prepared through the confinement derivation strategy.Owing to the high specific surface area(231 m² g^-1),ultra-thin Ti O2 nanosheets（150 nm long and 4nm thick）co-exposed with（101）and（001）crystal facets,and the plane-to-plane interaction between Ti O2 nanosheets and graphene,the electrode exhibited excellent visible-light absorption and photogenerated carrier life.The electrode showed excellent visible-light activated photocatalytic inactivation performance for three typical pathogenic bacteria（more than 99.99%）and efficient degradation performance for extracellular and intracellular ARGs（more than 98.33%）.The above structure properties also endowed the electrode with higher specific capacitance,higher pseudocapacitance contribution,lower ion diffusion and charge transfer resistance.The electrode showed superior desalination capacity(31.01 mg g^-1)and rate(1.36 mg g^-1 min^-1)at a cutoff voltage of 1.2 V,which was superior to similar metal oxide-based and carbon-based electrodes.（4）Study on the desalination and ARGs removal performance of Ti3C2Tx MXene nanotube membrane electrode:Ti3C2Tx MXene nanotube self-supporting membrane electrode was synthesized via mechanical force assisted alkali solution derivation method.The oxygen-containing functional groups on the electrode surface,nanotubes and the assembled network provided higher specific capacitance.The network also constructed one-dimensional and three-dimensional ion and electron transfer path,which significantly reduced the ion diffusion resistance and electron transfer resistance.The desalination capacity and desalination rate of the electrode(1.2 V,30m A g^-1)was up to 106.5 mg g^-1 and 0.87 mg g^-1 min^-1,respectively.Owing to the antibacterial property of MXene,the electrode exhibited excellent inactivation efficiency for four typical pathogens（more than 95%）.Moreover,in single pollutant system（ARGs or Na Cl）,combined pollutants system（Na Cl and ARGs）and simulated seawater,the electrode exhibited excellent desalination performance and removal efficiency to three intracellular and extracellular resistance genes（more than 90%）.And the removal performance showed no significant attenuation after four cycles.Compared with other ARGs removal technologies,CDI showed better comprehensive performance in removal efficiency,cost,energy consumption and large-scale.Based on faradaic CDI technology,this study designed novel（photo）electrode materials according to the characteristics of Na Cl and ARGs in water.This study realized the simultaneous and efficient removal of ARGs and Na Cl in combined pollutants system,and revealed the mechanism of desalination and ARGs removal.The study provided new ideas for the development and large-scale application of Faradaic CDI technology and solving the problem of shortage of fresh water resources.This study also provided technical guidance and theoretical basis for dealing with ARGs contamination in water and solving the problem of safety of drinking water quality.