Research On The Shape-controlled Fe₂O₃-ZrO₂ Catalysts In The Heterogenerous Fenton-like Recation Of Organic Pollutant Degradation

Pharmaceutical and personal care products(PPCPs)are essential for modern life,while the PPCPs have widely detected in the water due to their enormous use and chemical characteristics.Advanced Oxidation Process(AOPs)is an effective chemical oxidation technique in the water and wastewater treatment.Among the AOPs,Fenton reaction is widely used due to its mild reaction conditions and environmentally friendly oxidants.The traditional Fenton reaction has disadvantages at the operating conditions of low pH and in the formation of iron sludge.The reason limits its application in water and wastewater treatment.Heterogeneous Fenton-like system can improve the reaction operating conditions and become a research hotspot of Fenton technology.High-efficiency and stable heterogeneous catalyst is one of the key applications of this technology.In order to solve the problem of poor catalytic performance in the process of heterogeneous Fenton-like reaction,the stable and environmentally friendly ?-Fe2O3 is used to develop shape-controlled,highly effective and stable iron-based oxide catalysts with sulfamethazine as the main catalyst.It is proposed that the transition metal element Zr is doped in a-Fe2O3 to prepare Fe2O3-ZrO2 catalysts with different morphologies.The heterogeneous Fenton-like degradation of PPCPs is studied.The Fe2O3-ZrO2 catalysts with different morphologies of 0D/1D/2D and 3D were prepared by a hydrothermal/solvent methods.The catalytic properties of Fe2O3-ZrO2 catalysts with nanocubes(HZNCs),nanorods(HZNRs),nanotubes(HZNTs)and nanoplates(HZNPs)depended on their morphologies.The H2O2 adsorption and Fe2+site density on the catalyst surface affected the process of H2O2 decomposition to produce OH.The activity order of the Fe2O3-ZrO2 catalysts degrading sulfamethazine was HZNPs>HZNRs>HZNCs>HZNTs.HZNPs and HZNRs exhibited better degradation performance of SMT in the heterogeneous Fenton-like reaction at pH 3.0.The pseudo first order kinetic equation was obtained,and the apparent reaction rates were 1.5×10-2,6.8×10-3,1.7×10-3,and 9.3×10-4 min-1,for HZNPs,HZNRs,HZNCs and HZNTs,respectively.The adsorption capacity of H2O2 per unit specific surface area of HZNPs was 0.426 mg/m2,which was 1.7,1.7 and 3.7 times of HZNRs,HZNCs and HZNTs,respectively.The amount of OH radicals produced in the Fenton-like reaction was 4.52,2.24,2.20 and 0.58 ?mol/m2 for HZNPs,HZNRs,HZNCs and HZNTs,respectively.The catalytic performance of Fe2O3-ZrO2 catalysts with 3D morphologies was investigated under near-neutral conditions in the Fenton-like reaction degrading sulfamic dimethylpyrimidine(SMT),bisphenol A(BPA).phenol ibuprofen(IBP)and ciprofloxacin(CIP).The activity order of the catalysts was:F-HZNW>F-HZNP>F-HZNR.F-HZNW catalyst exhibited the best activity,and the removals of the pollutants exceeded 90%after 120min reaction.Using tert-butanol.KI and p-benzoquinone as quenchers of OH and O2·-VHO2-,the results indicated that the surface-bounded OH radicals played the important role in the Fenton-like reaction over the F-HZNW catalyst.The Fe2O3-ZrO2 catalysts with 0D/1D/2D and 3D morphologies was characterized by XRD,SEM,BET and XPS.The results were shown in the Fe2O3-ZrO2 catalysts that:(1)a-Fe2O3 was observed,and the intensity of ?-Fe2O3 peaks became weaker in the Zr addition;(2)the morphologies and sizes of a-Fe2O3 changed,and the crystal sizes of a-Fe2O3 became smaller;(3)the specific surface area of the catalyst increased significantly;(4)the amount of Fe2+on the surface of Fe2O3-ZrO2 catalysts was obtained.