Carbon Modified Copper Ferrite Nanomaterial: Synthesis, Performance And Fenton-like Application For Tetracycline Hydrochloride Degradation

In recent years,with the increase of people’s demand for drugs and personal care products,antibiotic residues are prevalent in the environment.Residual antibiotics released into water may cause organ damage or embryo toxicity.Traditional sewage treatment methods are difficult to completely remove antibiotics due to the poor biodegradability.Spinel copper ferrite（CuFe₂O₄）get widely concerned in antibiotic wastewater treatment due to its simple preparation,low cost,stable crystal structure and excellent catalytic performance.In this study,we prepared CuFe₂O₄ and carbon-modified C-CuFe₂O₄ to degrade tetracycline hydrochloride.Further,we revealed the structural characteristics and properties of CuFe₂O₄ and proposed the reaction mechanism along with degradation pathways,which would provide lightful reference for the modification of CuFe₂O₄ in Fenton-like application.The specific research content is as follows:（1）CuFe₂O₄ and C-CuFe₂O₄ were prepared by simple hydrothermal method.The structure,morphology and electronic properties of the prepared samples were studied.In the microscopic morphology,CuFe₂O₄ appears as a dense lump agglomeration,while 5%C-CuFe₂O₄ presents as a fluffy porous particle.XRD tests showed that the prepared catalyst samples were of high purity and appointed to spinel ferrite.FTIR detected C-C resonance and C=O vibration functional groups after carbon modification.XPS analysis revealed that carbon interacted with the spinel copper ferrite in the form of C-O-Fe and C-O-Cu bonds.In addition,both of CuFe₂O₄ and C-CuFe₂O₄ possess good magnetic properties,and the specific surface area and pore size of CuFe₂O₄ get increased after carbon doping.Moreover,compared with pristine CuFe₂O₄,the conductivity of carbon-modified CuFe₂O₄ is effectively improved.（2）The results of the pilot shaker system indicated that:The degradation of tetracycline hydrochloride by 5%C-CuFe₂O₄/H₂O₂ is obviously superior to other systems.When the catalyst dosage is 400 mg/L and hydrogen peroxide concentration is 20 m M,the removal rate of tetracycline hydrochloride by 5%C-CuFe₂O₄ reaches about 94%within 90 minutes.At p H=3,5,7,9 and 11,the catalytic degradation efficiency of tetracycline hydrochloride by 5%C-CuFe₂O₄ is 76.2%,92.6%,91.2%,88.4%and 55%,respectively.The neutral initial p H of the solution was more favorable for the degradation of tetracycline hydrochloride in 5%C-CuFe₂O₄/H₂O₂ system.In addition,the degradation efficiency of 5%C-CuFe₂O₄ remained above 80%after repeated use for 4 times.In order to explore the application performance of catalyst in actual water,this study carried out degradation tests by extracting actual river and lake water.Accordingly,the removal efficiency of tetracycline hydrochloride by 5%C-CuFe₂O₄ in tap water,Taozi Lake water and Xiangjiang water was 73.9%,70.5%and68.9%,respectively.The inhibition degree of common anions on 5%C-CuFe₂O₄/H₂O₂followed by CO₃^2->SO₄^2->NO₃^->Cl^-.（3）The main reactive radicals generated by 5%C-CuFe₂O₄/H₂O₂ system are·OH and·O₂^-.By analyzing the changes of XPS elements before and after the reaction,it can be deduced that copper and iron are involved in the redox reaction.The synergistic effects of Fe³⁺/Fe²⁺,Cu²⁺/Cu⁺and Cu²⁺/Fe²⁺were responsible for activating hydrogen peroxide to produce reactive radicals.The p,p,d orbitals of C,O,Cu and Fe can be hybridized to form C-O-Cu and C-O-Fe bonds,and electrons on carbon can be transferred to metals Cu and Fe along the C-O-Fe and C-O-Cu channels,thus forming electron-rich reaction centers around Fe and Cu.In addition,the main degradation products of tetracycline hydrochloride were detected by liquid chromatograph-mass spectrometer and the possible degradation pathway was proposed.