The purpose of this study is to explore the adsorption performance of meso-2,3-dimercaptosuccinic acid(DMSA)modified Fe3O4@SiO2 magnetic nanocomposite(Fe3O4@SiO2@DMSA)for Pb2+ions removal from aqueous solutions.The ef...The purpose of this study is to explore the adsorption performance of meso-2,3-dimercaptosuccinic acid(DMSA)modified Fe3O4@SiO2 magnetic nanocomposite(Fe3O4@SiO2@DMSA)for Pb2+ions removal from aqueous solutions.The effects of solution pH,initial concentration of Pb2+ions,contact time,and temperature on the amount of Pb2+adsorbed were investigated.Adsorption isotherms,adsorption kinetics,and thermodynamic analysis were also studied.The results showed that the maximum adsorption capacity of the Fe3O4@SiO2@DMSA composite is 50.5 mg/g at 298 K,which is higher than that of Fe3O4 and Fe3O4@SiO2 magnetic nanoparticles.The adsorption process agreed well with Langmuir adsorption isotherm models and pseudo second-order kinetics.The thermodynamic analysis revealed that the adsorption was spontaneous,endothermic and energetically driven in nature.展开更多
The core-shell structured TiO2/SiO2 @Fe3O4 photocatalysts were prepared using Fe3O4 as magnetic core,tetraethoxysilane（TEOS） as silica source and tetrabutyl titanate（TBOT） as titanium sources.The as-obtained struc...The core-shell structured TiO2/SiO2 @Fe3O4 photocatalysts were prepared using Fe3O4 as magnetic core,tetraethoxysilane（TEOS） as silica source and tetrabutyl titanate（TBOT） as titanium sources.The as-obtained structure was composed of a SiO2@Fe3O4 core and a porous TiO2 shell.The diameter of SiO2@Fe3O4 core was about 205 nm with thickness of porous TiO2 of about 5-6 nm.The 9%TiO2/6%SiO2@Fe3O4 microspheres possess the highest BET surface area and the BJH pore volume,which are 373.5 m2.g-1 and 0.28 cm3.g-1,respectively.The 9%TiO2/6%SiO2@Fe3O4 photocatalyst exhibited an excellent performance for the degradation of methyl orange and methylene blue dyes.Two different dyes were completely decolorized in 60 min under UV irradiation.The photocatalytic activity and the amount of catalyst were almost not decrease after recycling for 6 times by using external magnetic field.展开更多
In this study,(100)-oriented growth of Ba_(0.5)Sr_(0.5)TiO_3(BST)/LaNiO_3(LNO) stacks was obtained on Pt(111)/SiO_2/Si substrates by r.f.magnetron sputtering.The orientation of the subsequently deposited Ba_(0.5)Sr_(0...In this study,(100)-oriented growth of Ba_(0.5)Sr_(0.5)TiO_3(BST)/LaNiO_3(LNO) stacks was obtained on Pt(111)/SiO_2/Si substrates by r.f.magnetron sputtering.The orientation of the subsequently deposited Ba_(0.5)Sr_(0.5)TiO_3 thin film was strongly affected by the LNO under layer,and the BST thin film deposited on the(100)LNO-coated Si substrate was also found to have a significant(100)-oriented texture.Effects of LNO interlayer on the dielectric properties of BST thin films were investigated.As a result,the tunability of BST thin film was greatly improved with the insertion of(100)-oriented LNO under layer with proper thickness.展开更多
基金Project(2013DFA51290)supported by International S&T Cooperation Program of China
文摘The purpose of this study is to explore the adsorption performance of meso-2,3-dimercaptosuccinic acid(DMSA)modified Fe3O4@SiO2 magnetic nanocomposite(Fe3O4@SiO2@DMSA)for Pb2+ions removal from aqueous solutions.The effects of solution pH,initial concentration of Pb2+ions,contact time,and temperature on the amount of Pb2+adsorbed were investigated.Adsorption isotherms,adsorption kinetics,and thermodynamic analysis were also studied.The results showed that the maximum adsorption capacity of the Fe3O4@SiO2@DMSA composite is 50.5 mg/g at 298 K,which is higher than that of Fe3O4 and Fe3O4@SiO2 magnetic nanoparticles.The adsorption process agreed well with Langmuir adsorption isotherm models and pseudo second-order kinetics.The thermodynamic analysis revealed that the adsorption was spontaneous,endothermic and energetically driven in nature.
基金Supported by the National Natural Science Foundation of China（21173018,20473009）
文摘The core-shell structured TiO2/SiO2 @Fe3O4 photocatalysts were prepared using Fe3O4 as magnetic core,tetraethoxysilane（TEOS） as silica source and tetrabutyl titanate（TBOT） as titanium sources.The as-obtained structure was composed of a SiO2@Fe3O4 core and a porous TiO2 shell.The diameter of SiO2@Fe3O4 core was about 205 nm with thickness of porous TiO2 of about 5-6 nm.The 9%TiO2/6%SiO2@Fe3O4 microspheres possess the highest BET surface area and the BJH pore volume,which are 373.5 m2.g-1 and 0.28 cm3.g-1,respectively.The 9%TiO2/6%SiO2@Fe3O4 photocatalyst exhibited an excellent performance for the degradation of methyl orange and methylene blue dyes.Two different dyes were completely decolorized in 60 min under UV irradiation.The photocatalytic activity and the amount of catalyst were almost not decrease after recycling for 6 times by using external magnetic field.
基金the National Key Lab of Nano/Micro Fabrication Technology(No.9140C 790310060C79)the National Natural Science Foundation of China(No.60701012)
文摘In this study,(100)-oriented growth of Ba_(0.5)Sr_(0.5)TiO_3(BST)/LaNiO_3(LNO) stacks was obtained on Pt(111)/SiO_2/Si substrates by r.f.magnetron sputtering.The orientation of the subsequently deposited Ba_(0.5)Sr_(0.5)TiO_3 thin film was strongly affected by the LNO under layer,and the BST thin film deposited on the(100)LNO-coated Si substrate was also found to have a significant(100)-oriented texture.Effects of LNO interlayer on the dielectric properties of BST thin films were investigated.As a result,the tunability of BST thin film was greatly improved with the insertion of(100)-oriented LNO under layer with proper thickness.
