Preparation Of Rice Straw-derived Fiber Membrane Composites By Electrospinning And Study On Their Photocatalytic Properties

Environmental pollution and resource shortage are the main problems that human beings need to solve.The development of clean technology and renewable resources has become the focus of researchers all over the world.Because the use of solar energy and oxygen in the air for the oxidative decomposition of toxic compounds,Semiconductor photocatalytic technology presents a broad application prospects.China is a large agricultural country,and the burning of agricultural wastes such as rice stalks is one of the main sources of air pollution.In this paper,cellulose acetate（CA）was obtained from rice stem by separation,extraction and acetylation.Porous CA-CN and CA-P25fiber film photocatalysts were prepared by electrospinning with graphite phase carbon nitriding（g-C₃N₄,CN）and P25 semiconductor materials,which were used in visible light photocatalytic degradation of pollutants in water.The utilization of rice stem resources in water pollution control provides a new idea for alleviating energy shortage and environmental pollution control.The main research contents of this paper are as follows:1.Porous CA/CN fiber membrane photocatalyst:Using CA,OCN and PVP as raw materials,using electrostatic spinning technology to prepare CA/OCN/PVP composite fiber membrane with different OCN content.After PVP was dissolved in water and removed,porous CA/OCN fiber membrane photocatalyst was obtained.Compared with OCN nanosheets with the same equivalent,the photocatalytic activity of porous CA/OCN fiber films to degrade Rh B and tetracycline increased by 1.6 and 1.47 times,respectively,and the porous CA/OCN fiber films had good cycling stability and were easy to recycle.This is mainly because CA films effectively disperse OCN,expose more active surfaces and provide more active sites,thus promoting photocatalytic reactions.2.Porous CA/CN fiber membrane photocatalyst:Using CA,OCN and PVP as raw materials,using electrostatic spinning technology to prepare CA/OCN/PVP composite fiber membrane with different OCN content.After PVP was dissolved in water and removed,porous CA/OCN fiber membrane photocatalyst was obtained.Compared with OCN nanosheets,the photocatalytic activity of porous CA/OCN fiber films to degrade Rh B and tetracycline increased by 2 and 1.5 times,respectively,and the porous CA/OCN fiber films had good cycling stability and were easy to recycle.This is mainly because CA films effectively disperse OCN,expose more active surfaces and provide more active sites,thus promoting photocatalytic reactions.3.Porous C/P25 membrane photocatalyst:Using electrostatic spinning technology to prepare CA/P25 fiber membrane and calcination to prepare porous C/P25 membrane;The effect of calcination temperature on the adsorption and photocatalytic properties of C/P25 membranes was investigated.The results showed that the film stability was the highest when calcined at 750℃.The photocatalytic removal rates of Rh B and tetracycline reached 99.3%（within 20 min）and 98.6%（within 10 min）,respectively.