Controllable Preparation And Adsorption Properties Of Hollow Nano-carbon Spheres And Their Hybrid Fiber Films

Excessively discharged heavy metal ions cause serious environmental damage and waste of resources,which is an urgent problem to be solved.The adsorption method with simple operation and high efficiency is the current research hotspot,but most of the traditional inorganic adsorption materials and organic adsorption materials have problems of high cost,low efficiency,and easy to cause secondary pollution.They cannot meet the needs of wastewater removal well.High specific surface area,high group abundance and material durability are important factors that affect the adsorption performance,and the combination of inorganic adsorbents and organic adsorbents to prepare composite materials is a potential method.Based on this,this paper aims to develop a highly efficient removal of heavy metal ion,and designs small size uniformly dispersed active carbon sphere adsorbents and their hybrid membrane adsorbents around high surface area,high group abundance and stable adsorption structure.The adsorption behavior of hybrid fiber membrane to copper ions(Cu²⁺),lead ions(Pb²⁺)and chromium ions(Cr³⁺)in aqueous solution was systematically studied,and the adsorption mechanism of heavy metal ions was analyzed by combining the characterization results and adsorption performance.The specific research contents are as follows:?1?Preparation of nano-scale hollow carbon spheres and its adsorption properties for heavy metal ionsFactors such as the amount of ethanol and reaction temperature in the St???ber method were adjusted to control the size of the silica microspheres,and the activated carbon layer was covered on the surface of the silica microspheres by polycondensation reaction of phenolic resin.After carbonization at high temperature,hydrofluoric acid?HF?was used to etch the silica template,and finally KOH activation material was used to prepare nano-scale hollow carbon spheres.The adsorption behavior of activated carbon spheres for metal ions and organics in aqueous solution was systematically studied.The results showed that the hollow nano-carbon spheres had a minimum size of 80 nm and a core-shell structure.The surface of the material had a large number of active groups such as C=O,and the specific surface area was about 613.5 m²/g.Intermittent adsorption experiments showed that the maximum adsorption capacity of hollow carbon nanospheres for copper ions,lead ions and chromium ions were 71,74and 76 mg/g,respectively.The simulation found that the adsorption behavior of the material for metal ions was more in line with Langmuir and pseudo-second-order kinetic model.The adsorption process was mainly chemical adsorption,and physical adsorption is auxiliary adsorption.?2?Research on hollow nano carbon ball-based hybrid fiber membrane for removing heavy metal ion pollutionActivated carbon spheres were soaked in polydopamine?PDA?solution to modify the surface,and then hybrid fiber membranes with different adsorption structures were prepared by surface deposition method and electrospinning method,respectively.Characterization analysis showed that the surface of the hybrid membrane has rich functional groups,such as C-O,C=O and-OH.The hybrid fiber membranes prepared by surface deposition and electrospinning have different structures,and the specific surface area and cumulative pore volume were obviously increased,which were 63.2m²/g and 101.5 m²/g,and the cumulative pore volumes were 0.1670 cm³/g and 0.4617cm³/g.,respectively.The batch adsorption experiments proved that the adsorption capacity of the hybrid fiber membrane to pollutants was greatly improved compared with that of hollow nanocarbon spheres,such as 192 mg/g and 197 mg/g,respectively,The adsorption capacity of the hybrid fiber membrane could reach 92.2%of the maximum adsorption capacity within 30 min.Simulations showed that the adsorption of pollutants by hybrid fiber membranes conforms to Langmuir and pseudo-second-order kinetic models.The adsorption process was controlled by chemisorption.Finally,the adsorption mechanism of the hybrid membrane for pollutants was systematically studied.