Preparation And Photo-Fenton Properties Of Cellulose/ferrite Carbon Aerogel Composites

With the progress of human civilization and course of industrialization,the sharp sustainable development issues of human society have caused more and more attention such as resources,ecological environment deterioration and water pollution,which are threatening the survival of mankind;therefore,use of renewable energy and development of corresponding technology are significant ways to solve difficulties.As is known to all,solar is a treasure trove of clean and renewable.However,it is inefficient for people to employ the sunlight in nature.In recent years,the proposal of photocatalytic technology accelerates the conversion of sunlight and provides a meaningful theoretical basis for environmental governance and energy strategy.The ferrites（MFe₂O₄,M=Ni,Zn,Co,etc.）have a narrow band gap and strong response capacity to sunlight.On the other hand,cellulose,as one of the important biomass sources,is an important carbon source precursor.Xinjiang,as an important cotton production base in China,is famous for its cotton linters,and the cellulose content is over 95%.In this study,we will make full use of the two renewable resources mentioned above to synthesize a series of cellulose based carbon aerogel nanocomposites.Methylene blue solution（MB）is used to simulate pollutants,and a series of scientific characterization methods are used to research the structure,morphology,magnetism and photocatalytic properties of these nanocomposites in detail.The main contents and conclusions of the investigations are as follows:（1）Cotton linter cellulose as a carbon source is dissolved in alkaline urine solvent system by means of using the principle of coprecipitation to prepare Zn Fe₂O₄.The loading mass of cotton linter cellulose to Zn Fe₂O₄was controlled by changing the adding of Zn（NO₃）₂·6H₂O and Fe（NO₃）₃·9H₂O,which was placed to freezer dryer at-40℃obtaining Cellulose/Zn Fe₂O₄hybrid aerogels.When it was carbonized at 600℃,the Cellulose/Zn Fe₂O₄ carbon aerogel nanocomposites（Cellulose/Zn Fe₂O₄-CA-600℃）were prepared.The samples of different loading mass were measured,whose results manifested that Cellulose/80%Zn Fe₂O₄-CA-600℃owned good performance.The XRD,SEM,FT-IR,EDS,Mapping,VSM,XPS,BET and steady/transient fluorescence,EIS,DRS etc.were conducted to investigate the morphology,structure,photoelectric properties of samples.According to the above consequences,it can be concluded that the performance of composites was superior to the single Zn Fe₂O₄ and carbon aerogel.When the p H of the solution was changed and H₂O₂ was added for the photodegradation of MB solution,the rate of photodegradation of MB solution was increased as well as the synergistic effect of both can increased by 10 times.The photodegradation reaction was conformed to the first-order kinetic equation on the basis of kinetic curves of photodegradation.In addition,the photodegradation efficiency of sample was 84%after five cycles.（2）According to the above loading method,the doped metal element was replaced with Ni as well as Ni（NO₃）₂·6H₂O was added to form cellulose/Ni Fe₂O₄ hybrid aerogels.Cellulose/Ni Fe₂O₄ carbon aerogels were prepared（Cellulose/Ni Fe₂O₄-CA）via adjusting different carbonization temperature and loading mass.Photocatalytic performance was detected that at 700℃（Cellulose/Ni Fe₂O₄-CA-700℃）has a good photodegradation performance for MB.Compared with that of Cellulose/Zn Fe₂O₄-CA-600℃,the photocatalytic performance increased to 0.088 min^-1with the photodegradation conditions of p H=11and C（H₂O₂）=0.2 mol/L.（3）Adding Zn（NO₃）₂·6H₂O,Fe（NO₃）₃·9H₂O and Ni（NO₃）₂·6H₂O in light of mole ratio into Hydrogel alkaline substrate synthesized cellulose/Ni_xZn_1-xFe₂O₄carbon aerogels nanocomposites(Cellulose/Ni_xZn_1-xFe₂O₄–CA)after freeze drying and different carbonized temperature,and the photodegradation of samples to MB solution was researched.It is concluded that Cellulose/50%Ni_0.3Zn_0.7Fe₂O₄-CA-700℃has good photodegradation properties compared with the other sample.The photodegradation environment was further modified by adjusting p H and H₂O₂ so that the photodegradation rate was increased to 0.032 min^-1.