Development Of N-doped Magnetic Chitn Porous Carbon Microspheres And Its Property Research

Chitin mostly comes from the crab and shrimp shells.It is a natural,non-toxic and renewable polysaccharide.Chitin is rich in N-acetyl groups,and Nitrogen can be evenly distributed in the carbon ring through high-temperature calcination,leading to produce a new N-doped chitin material.Therefore,under the background of"carbon neutralization",this paper uses biomass compound chitin to prepare magnetic chitin carbon spheres and N-doped magnetic porous chitin titanium dioxide carbon spheres respectively,which are used as adsorbents and photocatalysts to realize the efficient adsorption and embedding of curcumin and the efficient degradation of methyl orange pollutants.Magnetic porous carbon microspheres（NMCMs）were prepared using sol-gel method from chitin,and which was used to adsorption of curcumin via physical loading method.The physical and chemical properties of NMCMs and the adsorption capacity were all studied in detail.The results of this study showed that NMCMs exhibited 3D spherical structure with hierarchical pores,high specific surface area and magnetic responsive ability.Meanwhile,NMCMs（10mg）has good adsorption capacity for curcumin(50 mg·L^-1)with maximum adsorption amount of 132.77mg·g^-1at 35℃.The adsorption processes agreed with the second-order kinetic and Langmuir model.A novel catalyst of N-doped magnetic three-dimensional（3D）carbon microspheres@TiO₂with a nanofibrous porous architecture（NMCMs@TiO₂）was developed from the low-cost biomass of chitin.The NMCMs@TiO₂consist of N-doped carbon nanofibers,a 3D porous architecture,and a high surface area.TiO₂nanoparticles were uniformly immobilized on the N-doped carbon nanofibers,resulting in many catalytic sites.The current density of NMCMs@TiO₂was approximately 0.247u Acm^-2with 1.65 times than that of pure TiO₂,and the bandgap of NMCMs@TiO₂was only 1.91eV.Additionally,NMCMs@TiO₂had excellent adsorption capability for methyl orange（MO）（40.15%）in the dark after 40 min.Under the optimized conditions,NMCMs@TiO₂exhibited remarkable photodegradation performance for MO solutions,the degradation efficiency of MO was approximately 83.80%under UV irradiation,and that of was maintained at68.07%even in cloudy weather,respectively.Meanwhile,NMCMs@TiO₂possess good potential for practical applications with long-term stability and can be easily recycled from solutions under an external magnet.Therefore,NMCMs and NMCMs@TiO₂were prepared from chitin,a low-cost biomass based material.The two new chitin materials have three-dimensional porous structure and high specific area.They are a good adsorbent and catalyst with a wide range of uses,which provides a reference for the high-value utilization of biomass waste.