Study On The Preparation And Application Of Lignocellulosic Biomass And MXene Composites

As members of lignocellulosic biomass,cellulose and lignin can be compounded with MXene to prepare functional materials with excellent properties by virtue of their own structural characteristics and chemical properties,and realize the high-value utilization of biomass resources.In this paper,TEMPO oxidized cellulose nanofibers（TOCNFs）were embedded into the middle of multilayer Ti₃C₂T_x MXene sheets by ultrasonic treatment,and then a highly photoactive Carbonized TOCNFs/Ti₃C₂T_xMXene/g-C₃N₄（CMCN）photocatalyst was synthesized by calcining TOCNFs/Ti₃C₂T_x MXene and urea mixed solution.At the same time,lignin nanoparticles（LNPs）with uniform size were prepared through solvent replacement method with alkali lignin,then the LNPs were loaded on the surface of MXene by ultrasonic treatment.When Ag NO₃ solution was added into LNPs/MXene solution,the MXene/Ag composites were prepared with Ag element grown in situ on the surface of MXene.The as-prepared CMCN and MXene/Ag composites were characterized and analyzed by relevant analytical methods,and their applications in photocatalysis and lithium-ion anode materials were explored respectively.Firstly,the effect of TOCNFs on the catalytic degradation of methylene blue（MB）,rhodamine b（Rh B）and tetracycline（TC）was explored.The study found that TOCNFs were successfully embedded in the middle of Ti₃C₂T_x MXene sheets,and the valence band,conduction band and forbidden band width of the prepared CMCN material were 1.38 e V,-1.15 e V and 2.53 e V,respectively.The photocatalytic degradation efficiencies of CMCN for MB,Rh B and TC were 96.5%（210 min）,95.4%（60 min）and 86.5%（60 min）.Then,the application in the field of lithium battery anode materials for MXene/Ag composite material was explored.The study found that the particle size of LNPs was about102 nm when the initial concentration of alkali lignin was 2 mg/m L.The charge-discharge test showed that the MXene/Ag composite electrode exhibit an extraordinary long cycle lifetime with a large capacity.The long cycle test at 5 C current density showed that the specific capacitance of MXene/Ag increases firstly and then decreases,and the maximum specific capacity and the specific capacity of charge and discharge for the 3000th time are216.54 m Ah g^-1 and 85.71 m Ah g^-1,respectively.