In this study,Fe3 O4@SiO2@ZnO:La microspheres were successfully prepared.The microspheres have the advantages of both ZnO doped with La and the Fe3 O4@SiO2 structure such that the former improves the photocatalytic ac...In this study,Fe3 O4@SiO2@ZnO:La microspheres were successfully prepared.The microspheres have the advantages of both ZnO doped with La and the Fe3 O4@SiO2 structure such that the former improves the photocatalytic activity of ZnO and the latter can be reused.The X-ray diffraction(XRD),a field emission scanning electron microscope(SEM),a field emission transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),and a vibrating sample magnetometer(VSM)were used to characterize Fe3 O4@SiO2@ZnO:La microspheres.Methyl orange was used as the model molecule to study the effect of the Zn2+concentration and the doping amount of La on the photocatalytic activity of Fe3 O4@SiO2@ZnO:La microspheres.Results show that in the synthesis of Fe3 O4@SiO2@ZnO:La microspheres,photocatalytic activity of the microspheres is enhanced first and weakened later with the increase of Zn2+concentration.In the La doping process,the photocatalytic activity of Fe3 O4@SiO2@ZnO:La microspheres is enhanced with the increase in the La doping amount.The magnetic photocatalysts not only have high photocatalytic activity,but also can be reused.After being reused five times,the photocatalyst’s degradation rate of methyl orange is still as high as 81%,which shows that magnetic photocatalysts have prospective wider applications in photocatalytic degradation of dye wastewater.展开更多
To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL...To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL-101 magnetic composite material was successfully synthesized via the one-pot method.Preparation conditions were optimized and structural characterization of this material conducted using FTIR,SEM,EDS,XRD and Hysteresis analysis.The results show that this composite exhibits a more rapid fluoride adsorption dynamics and a higher fluoride adsorption capacity(18.34 mg/g)and its adsorption behavior fitted for the first order dynamic model and the Freundlich isotherm model.The adsorption of fluorine by this composite is mainly physical adsorption according to the mean adsorption energy(1.216 kJ/mol).The interfering ions co-existed in fluoride-containing solutions,like HCO_(3)^(-),NO^(-)and Cl^(-),have a significant effect on fluorine adsorption.This composite has also been proved with magnetism,higher adsorption selectivity and satisfactory reusability.When this composite is employed as an adsorbent for adsorption removing fluoride in zinc sulfate electrolyte,it exhibits higher pH-dependent behavior as well as high fluoride removal efficiency at pH 6.5.展开更多
In this paper,chemical co-precipitation method was employed to synthesize Fe3O4 nanoparticles which can be well dispersed in water by using citric acid as a surfactant.Afterwards,by using Fe3O4 nanoparticles as seeds ...In this paper,chemical co-precipitation method was employed to synthesize Fe3O4 nanoparticles which can be well dispersed in water by using citric acid as a surfactant.Afterwards,by using Fe3O4 nanoparticles as seeds in a Triton X-100/hexanol/cyclohexane/water reverse microemulsion system,the core-shell structural Fe3O4@SiO2 nanocomposite particles were prepared via hydrolysis and condensation of tetraethyl orthosilicate(TEOS) under the catalysis of alkali.The effects of different stirring methods and the concentration of TEOS on the morphology of Fe3O4@SiO2 nanoparticles were investigated.The results show that the mechanical stirring can effectively control the morphology of composite nanoparticles to form a good dispersion and spherical morphology of core-shell nanoparticles.With the increase of TEOS concentration,the thickness of the SiO2 shell increases,and the morphology of the composite particles becomes more uniform.展开更多
基金Project supported by the National Natural Science Foundation of China(31560466,20968005)。
文摘In this study,Fe3 O4@SiO2@ZnO:La microspheres were successfully prepared.The microspheres have the advantages of both ZnO doped with La and the Fe3 O4@SiO2 structure such that the former improves the photocatalytic activity of ZnO and the latter can be reused.The X-ray diffraction(XRD),a field emission scanning electron microscope(SEM),a field emission transmission electron microscope(TEM),X-ray photoelectron spectroscopy(XPS),and a vibrating sample magnetometer(VSM)were used to characterize Fe3 O4@SiO2@ZnO:La microspheres.Methyl orange was used as the model molecule to study the effect of the Zn2+concentration and the doping amount of La on the photocatalytic activity of Fe3 O4@SiO2@ZnO:La microspheres.Results show that in the synthesis of Fe3 O4@SiO2@ZnO:La microspheres,photocatalytic activity of the microspheres is enhanced first and weakened later with the increase of Zn2+concentration.In the La doping process,the photocatalytic activity of Fe3 O4@SiO2@ZnO:La microspheres is enhanced with the increase in the La doping amount.The magnetic photocatalysts not only have high photocatalytic activity,but also can be reused.After being reused five times,the photocatalyst’s degradation rate of methyl orange is still as high as 81%,which shows that magnetic photocatalysts have prospective wider applications in photocatalytic degradation of dye wastewater.
基金National Natural Science Foundation of China(21865011)2024 Innovation and Entrepreneurship Project of College Student in Jishou University(JDCX20241122)。
文摘To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL-101 magnetic composite material was successfully synthesized via the one-pot method.Preparation conditions were optimized and structural characterization of this material conducted using FTIR,SEM,EDS,XRD and Hysteresis analysis.The results show that this composite exhibits a more rapid fluoride adsorption dynamics and a higher fluoride adsorption capacity(18.34 mg/g)and its adsorption behavior fitted for the first order dynamic model and the Freundlich isotherm model.The adsorption of fluorine by this composite is mainly physical adsorption according to the mean adsorption energy(1.216 kJ/mol).The interfering ions co-existed in fluoride-containing solutions,like HCO_(3)^(-),NO^(-)and Cl^(-),have a significant effect on fluorine adsorption.This composite has also been proved with magnetism,higher adsorption selectivity and satisfactory reusability.When this composite is employed as an adsorbent for adsorption removing fluoride in zinc sulfate electrolyte,it exhibits higher pH-dependent behavior as well as high fluoride removal efficiency at pH 6.5.
文摘In this paper,chemical co-precipitation method was employed to synthesize Fe3O4 nanoparticles which can be well dispersed in water by using citric acid as a surfactant.Afterwards,by using Fe3O4 nanoparticles as seeds in a Triton X-100/hexanol/cyclohexane/water reverse microemulsion system,the core-shell structural Fe3O4@SiO2 nanocomposite particles were prepared via hydrolysis and condensation of tetraethyl orthosilicate(TEOS) under the catalysis of alkali.The effects of different stirring methods and the concentration of TEOS on the morphology of Fe3O4@SiO2 nanoparticles were investigated.The results show that the mechanical stirring can effectively control the morphology of composite nanoparticles to form a good dispersion and spherical morphology of core-shell nanoparticles.With the increase of TEOS concentration,the thickness of the SiO2 shell increases,and the morphology of the composite particles becomes more uniform.
