Study On Preparation,structure And Application Of Nitrogen-doped Nanocarbon Materials With Magadiite As Template

Carbon materials doped and modified by heterogeneous elements have been confirmed good electronic and chemical properties,and are widely used in sensing detection,water treatment and other fields.In recent years,researchers have continuously reported the doping methods and applications of carbon materials such as graphene,porous carbon,carbon nanotubes,nanofibers,and fullerenes.However,these preparation methods have defects such as complicated steps,low doping amount,and instability.In this paper,with a one-step synthesis the low-cost and widely-sourced magadiite(MAG)was selected as the hard template,pyrrole monomer(Py)was selected as the source of C and N elements,the method was used to preparing the precursor of nitrogen-doped carbon nanomaterials.The steps were simple and the prepared nitrogen-doped nanometer Carbon materials(CP)had shown excellent performance in sensing detection and specific dye adsorption.Using laboratory-made magadiite as a template and pyrrole as the initial carbon source and nitrogen source,a nitrogen-doped carbon nanomaterial was prepared by the template method,and the process conditions were optimized with kinds of characterized.Through XRD,FTIR,and BET characterization,it was found that this template method successfully prepared nitrogen-doped carbon nanomaterials.The process of calcination and etching enabled the template to effectively play a role in isolation and was finally removed.The addition of the template agent effectively increased the specific surface area of the material,making the specific surface area of the nitrogen-doped carbon nanomaterials reached 308.74 m~2/g,which was 29.56 times higher than the control group without the template MAG,and the pore volume increaseed 23.35 times.By adjusting the preparation conditions of the precursor,the calcination temperature,and changing the drying method,the best process for the preparation of nitrogen-doped carbon nanomaterials by the MAG template method was determined.When the calcination temperature was at 600℃,the N doping amount was about 7.22%.CP nitrogen-doped carbon nanomaterials was proved typical peroxidase-like activity.Compared with natural peroxidase(HRP),which is greatly restricted by p H and temperature,the enzyme-like activity of CP nitrogen-doped carbon nanomaterials maintained high catalytic activity under extreme conditions such as strong acid and high temperature.,which equipped it with potential for wide application and stable storage.The study of its catalytic mechanism showed that the peroxidase-like activity of CP material comes from its high specific surface area and stable negative charge.The reaction kinetic data conformed to the typical Michaelis-Menten model.The calculation of its key parameters showed that its affinity to the substrate was higher than that of the natural enzyme,and the peroxidase-like activity was better.Applying it to the content detection of specific substances,the detection range and detection limit of hydrogen peroxide,glucose and ascorbic acid based on CP could be determined according to the linear range.This article also applied CP nitrogen-doped carbon nanomaterials to treating Congo Red dye wastewater,and the results showed that its maximum adsorption capacity could reach558.97 mg/g.The adsorption process of CR can be described by the quasi-second-order kinetic equation and the Langmuir thermodynamic model.It belonged to the spontaneous adsorption process and was an endothermic reaction.The adsorption reaction of CR by CP adsorbent followed the law of single-layer chemical adsorption.Its high adsorption capacity comes from high specific surface area and rich functional groups after doping on the surface of the material.This article not only provided a novel method for preparing nitrogen-doped carbon materials with adjustable morphology by template method,but also provided an idea for the preparation of other hetero-element-doped carbon materials.It is of reference significance for the development of chemical sensor detectors and new adsorbents based on nitrogen-doped nano-carbon.