Preparation Of MnO₂@Ti₃C₂T_x/Cellulose Acetate Composite Film And Its Electrosorption Properties For Cu²⁺

In the traditional printing and dyeing industry,a large number of dyes and additives conaining heavy metal ions are usually used,of which about 12%of heavy metal ions will be discharged in the form of wastewater.Copper-containing wastewater does serious harm to the natural environment and human health.Therefore,how to effectively treat copper-containing wastewater is of great significance to the sustainable development of the natural environment,human health and social economy.Conventional methods of removing heavy metal ions from wastewate are costly,complicated and may cause secondary pollution,while electrosorption technology is simple,low-cost and free of secondary pollution,which has broad application prospects.In this paper.based on the excellent performance of MXene(Ti3C2Tx)two-dimensional nanosheets.Ti3C2Tx/cellulose acetate composite films and MnO2@Ti3C2Tx/cellulose acetate composite films were constructed respectively,and their electrosorption Cu2+ properties were compared.The main research contents are as follows:(1)Ti3C2Tx was prepared by HCl/LiF etching method,and was used as a conductive filler to physically blend with cellulose acetate,and Ti3C2Tx/cellulose acetate composite film was prepared by streaming-casting method.The effects of doping ratio of Ti3C2Tx on the structure,electrochemical performance and electrosorption properties of the composite films were investigated.The results show that the composite films have good flexibility.The Ti3C2Tx layers are stacked in order,and the interlayer is doped with cellulose acetate,which expands the innerlayer spacing.However,the lamellar stacking phenomenon becomes more serious with the imcrease of Ti2C2Tx content,and the specific surface area of the composite films decreases with the increase of Ti3C2Tx content.The adsorption capacity of Cu2+ increased with the increase of the voltage at both ends of the electrode and the initial concentration of the solution.When the mass ratio of Ti3C2Tx to cellulose acetate was 0.75,the adsorption capacity of the composite film reached 3.39 mg/g when the concentration of 10 mg/L CuSO4 solution was applied with an external voltage of-1V.(2)In order to improve the stacking of Ti3C2Tx 2D lamellae in Ti3C2Tx/cellulose acetate composite films,MnO2@Ti3C2Tx composite material was prepared by in-situ growth of MnO2 rods between Ti3C2Tx 2D lamellae by hydrothermal method,and MnO2@Ti3C2Tx/cellulose acetate composite film was prepared by fluidized process.The effects of MnO2 doping ratio on the structure,electrochemical performance and electrosorption properties of the composite films were investigated.The results show that MnO2 is successfully loaded and intercalated between Ti3C2Tx slices,which effectively increases the layer spacing.With the increase of MnO2 content,the layered structure of the film decreased obviously,and the internal pores increased,and the structure became looser.In addition,compared with Ti3C2Tx/cellulose acetate composite films,the specific surface area and specific capacitance are improved effectively.In addition,the adsorption capacity of Cu2+ can reach 4.27 mg/g under the same adsorption conditions,and the removal rate of Cu2+ is nearly two times higher than that of Ti3C2Tx/cellulose acetate composite film.