采用溶胶-凝胶法制备了纳米CuFe2O4,然后与TiO2固相烧结成复合光催化剂,并通过TEM,XRD和UV-visDRS对复合光催化剂进行了表征,表明样品由粒径约为80 nm的粒子组成,晶体结构均匀。以大肠杆菌为研究对象,考察了复合光催化剂在模拟太阳光(150 W氙灯,λ=200~900 nm)照射下的杀菌性能。结果表明:复合光催化剂比单一光催化剂杀菌效果好,在最佳条件下,模拟太阳光照射30 min后,CuFe2O4/TiO2复合光催化剂的杀菌率分别为单纯CuFe2O4和TiO2杀菌率的1.71倍和1.13倍。复合光催化剂杀菌性能受CuFe2O4与TiO2质量比及固相合成时焙烧温度的影响,当TiO2质量分数为80%、焙烧温度为600℃时,所制得的复合光催化剂处理大肠杆菌,在模拟太阳光照射30 min后,细菌的存活率仅为3.2%,而单纯CuFe2O4和TiO2光催化剂在最佳条件下杀菌30 min后细菌存活率分别为43.3%和14.2%。同样条件下在黑暗中使用催化剂或在光照下不用催化剂时细菌存活率分别为97.0%,93.2%。
Copper ferrite(CuFe2O4) nanoparticles were synthesized by sol-gel method and compounded with TiO2 to form CuFe2O4/TiO2 composite photocatalyst via solid-state reaction.The composite photocatalyst was characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD) and UV-vis diffuse reflectance spectrum(UV-vis DRS).It tells that the sample prepared is composed of nanoparticles with a grain size of about 80 nm and features uniform crystal structure.The photocatalytic inactivation of Escherichia coli,a Gram-negative bacterium,was performed with the photocatalyst to investigate its photocatalytic bactericidal capability under simulated sunlight(150 W xenon lamp,λ=200~900 nm) irradiation.The results show that CuFe2O4/TiO2 composite photocatalyst exhibites a much better photocatalytic activity than single CuFe2O4 or TiO2.Under optimal conditions,after 30 min irradiation of the simulated sunlight,the photocatalytic sterilization efficiency of CuFe2O4/TiO2 is 1.71 and 1.13 times more than that of CuFe2O4 and TiO2,respectively.The mass ratio of CuFe2O4 to TiO2 and the calcination temperature for solid-phase synthesis have effects on the bactericidal performance of the composite.When the photocatalyst prepared at 80% TiO2 mass fraction and 600 ℃ calcination temperature is used to treat Escherichia coli,its survival ratio is only 3.2% after 30 mins simulated sunlight irradiation.However,when CuFe2O4 or TiO2 is used under optimum conditions the survival ratio is 43.3% or 14.2% after 30 mins irradiation.Using photocatalyst in the dark and no photocatalyst in the light resulted in the survival ratio of Escherichia coli of 97.0% and 93.2%,respectively under the same conditions.