The ESIX Properties Of BiOCL Modified Electrode

Electrochemically switch ion exchange?ESIX?is a novel environmentally ion separation technology,especially for low concentration ions it can also achieve good separation performance.In ESIX,the insert and release of ions can be realized by exchanging the potential of the electrode,so that the secondary chemical waste produced during regeneration in other separation methods can be avoided.The key to ESIX is to develop new electroactive materials towards target ions.Electroactive materials have electron and ion conductivity.At present,electroactive materials included organic conductive polymers?such as polyaniline,polypyrrole,polyethylene dioxythiophene,etc.?and inorganic transition metal materials?double metal hydroxide,ferricyanide,etc.?and organic-inorganic composite materials.In this paper,for the removal of cesium,the bismuth oxychloride exposed with?101?crystal facets was used to realize the potential triggered removal of cerium ions.And used the electrochemical quartz crystal microbalance to further explore the ion exchange properties of bismuth oxychloride with exposed?001?crystal facets.As a kind of radioactive pollutant,cesium was harmful to the environment and human benings for its long half-life and easy diffusion.As an inorganic electroactive material,bismuth oxychloride has been widely used in environmental protection and energy regeneration due to its unique layer structure,semiconductor property and excellent photocatalytic properties.Because the ¹³⁷Cs is very harmful,in this paper we use non-radioactive cesium chloride to simulate the wastewater of cesium and the bismuth oxychloride exposed with?101?crystal facets?BOC-1?was synthesized by hydrothermal method,and the electroactive film was prepared by coating method.Scanning electron microscopy?SEM?,X-ray diffractometry?XRD?and X-ray photoelectron spectroscopy?XPS?were used to characterize the bismuth oxychloride and bismuth oxychloride coated electroactive film.The cesium separation performance of the bismuth oxychloride coated electroactive film was invesitgated.Studies revealed that for BOC-1/PVDF electroactive membranes,as the adsorption potential increases from 0 V to-0.7 V,the adsorption rate and adsorption capacity of Cs⁺increase.Experiments showed that the addition of conductive carbon black is beneficial to enhance the adsorption effect of cesium.For different initial concentrations of simulated cesium ion wastewater,the adsorption of cesium ions by BOC-1/SP/PVDF electroactive film is fitted to quasi-secondary kinetics.The BOC-1/SP/PVDF electroactive film has effective selectivity towards cesium ions in a binary mixed solution of Li⁺/Cs⁺and Na⁺/Cs⁺,respectively.And it was found that the electroactive fim was sensitive to potential at the initial stage in stability experiments.The adsorption effect of the electroactive film prepared by bismuth oxychloride with different exposed facets was also investigated and the effect of the solution pH value on the adsorption of cesium ions was also studied for the BOC-2/SP/PVDF electroactive film.In order to further study the electroactive and electrochemically switch ion exchange property of BOC-2,the cyclic voltammetry was tested in acidic,basic and neutral salt solutions by BOC-2 coated platinum electrode.And the effect of redox voltage on the electrode material in neutral salt solution was investigated by SEM and XRD.The electrochemically switch ion exchange behavior of the BOC-2 modified electrode was detected by cyclic voltammetry?CV?combined with electrochemical quartz crystal microbalance technology?EQCM?in different metal ion solutions.The results showed that under the condition of power-on,BOC-2 material was more stable in neutral solutions,and it had a single cation exchange property for Li⁺and Na⁺,and the exchange capacity were25 mg/g and 40 mg/g,respectively.And it has a single cation exchange property for Cu²⁺,the exchange capacity was 50 mg/g.