Study On Preparation Of Biomass Composite Catalyst And Its Photocatalytic Performance

The development and utilization of biomass energy can effectively inprove the rural environment and solve the energy crisis.Microcrystalline cellulose（MCC）was used as the raw material to prepare nanocrystalline cellulose（NCC）by the sulfuric acid hydrolysis method.The reaction conditions of the acidolysis process were optimized based on the evaluation goals of yield,particle size distribution,and potential（Sulfuric acid concentration,reaction time,reaction temperature）.The optimized preparation parameters of NCC are as follows:MCC:H₂SO₄=1:15,sulfuric acid concentration is 58 wt%,reaction time is 90min,reaction temperature is 50℃,NCC yield under these conditions is 64.97%,and the absolute value of the potential is 14.84 m V,and the average particle size is 334.52 nm.The crystalline structure of NCC is cellulose type I.The Hummers method was used to prepare graphene oxide（GO）,and NCC-GO and NCC-r GO composite materials were prepared.Using NCC as the base material,Ti O₂/NCC,N-Ti O₂/NCC,N-Ti O₂/NCC-r GO composites materials were prepared by one-step hydrothermal method and freeze-drying method,and phenol was used as the target pollutant for catalytic performance investigation.On the basis of screening the degradation reaction conditions of phenol solution,the structure characterization and performance study of composite materials were carried out.The results are as follows:During the degradation process,the temperature,light intensity,lamp strip power,etc.would have a greater impact on the reaction results.Under blue light for 180 min,0.1 g catalyst addition,0.025 g/L phenol initial concentration,and at the same time,the best reaction performance can be achieved under the reaction conditions catalyzed by blue light and catalyst;the preparation of biomass composite material has no effect on the crystal structure of Ti O₂,and it still exists in the anatase type with higher crystallinity,and the visible light catalytic performance of Ti O₂is greatly improved.;Ti O₂/NCC 0.5 can reach 37.82%a degradation rate of phenol;N 0.6-Ti O₂/NCC can reach a degradation rate of 55.43%;N-Ti O₂/NCC-r GO 0.05 can reach a degradation rate of 77.3%;the band gap of N-Ti O₂/NCC-r GO is 2.91 e V,the absorption sideband is 444 nm.In order to further study the effect of Cu²⁺loading on the structure and performance of the catalyst,Cu（1）/N-Ti O₂/NCC-r GO and Cu（2）/N-Ti O₂/NCC-r GO was prepared by impregnation method and hydrothermal method.In the XRD spectrum,it is observed that the former is an ionic load,while the latter has elemental copper and Cu₂O formation.The band gaps of Cu（1）/N-Ti O₂/NCC-r GO and Cu（2）/N-Ti O₂/NCC-r GO are 2.80 e V and 2.89 e V,and the absorption sidebands are 482 nm and 459 nm,respectively.The effect of loading on the reaction performance was investigated.The specific surface area of 10%Cu（1）/N-Ti O₂/NCC-r GO was 87.42 m²·g^-1,the pore volume was 0.37 cm³·g^-1,and the average pore size was 13.83 nm.The degradation rate of Cu（1）/N-Ti O₂/NCC-r GO is up to 78.91%,and the degradation rate of Cu（2）/N-Ti O₂/NCC-r GO is up to 75.08%.Although the degradation rate is not much different from that without Cu²⁺loading,but the Cu²⁺loading greatly shortens the reaction time.