磁性多孔尖晶石铁氧体制备及催化臭氧性能

为了提高臭氧氧化水中难降解有机物性能,采用溶胶–凝胶法合成了磁性多孔尖晶石铁氧体NiFe2O4和MnFe2O4.通过SEM、XRD、VSM和XPS对其性能进行表征,对催化剂不同存在条件下催化臭氧降解水中邻苯二甲酸二丁酯(DBP)的效果、催化臭氧化机理及催化剂的稳定性进行了探讨.结果表明:两种催化剂均为磁性、多孔状、尖晶石结构铁氧体,NiFe2O4和MnFe2O4对催化臭氧化DBP具有良好的强化能力,比单独臭氧化体系对DBP去除率可分别提高54%和47%,NiFe2O4催化臭氧化能力强于MnFe2O4.两种催化剂催化臭氧降解DBP的反应均遵循羟基自由基机理,反应过程中水中金属离子溶出均低于0.06 mg/L,结构稳定,易于回收处理.

Study on the preparation and the characters of catalytic ozonation on the magnetic porous ferrospinel

To improve the performance of ozonation of refractory organic matter in the water,the magnetic porous ferrospinel NiFe₂O₄ and MnFe₂O₄ were synthesized by a sol-gel process.SEM,XRD,VSM and XPS were used to characterize the catalysts.The catalytic ozonation performances of the catalysts under different conditions on the degradation of dibutyl phthalate (DBP) were studied.The degradation mechanism and the stability were also investigated.The results showed that the two catalysts were magnetic,large pore,and typical spinel ferrites.NiFe₂O₄ and MnFe₂O₄ showed good catalytic characters for the ozone decompose on DBP degradation.The removal rates of DBP were improved by 54% and 47% in the catalytic ozonation of NiFe₂O₄ and MnFe₂O₄,respectively,and NiFe₂O₄ showed better catalytic ozonation ability than that of MnFe₂O₄.The degradation of DBP followed the hydroxyl radical reaction mechanism in the two catalytic ozonation system.The dissolved metal ions from the catalysts in the water were lower at 0.06 mg/L,and the catalysts were stable easy recoverable.