title: Fabrication of Ellipsoidal Silica Yolk-Shell Magnetic Structures with Extremely Stable Au Nanoparticles as Highly Reactive and Recoverable Catalysts.
abstract: A novel strategy was reported for the fabrication of yolk-shell magnetic MFSVmS-Au nanocomposites (NCs) consisting of double-layered ellipsoidal mesoporous silica shells, numerous sub-4 nm Au nanoparticles (NPs), and magnetic Fe central cores. The hierarchical FSVmS NCs with ellipsoidal α-Fe2O3@mSiO2/mSiO2as yolks/shells were first prepared through the facile sol-gel template-assisted method, and plenty of extremely stable ultrafine Au NPs were postencapsulated within interlayer cavities through the unique deposition-precipitation method mediated with Au(en)2Cl3compounds. Notably, ethylenediamine ligands were used to synthesize the stable cationic complexes, [Au(en)2]3+, that readily underwent the deprotonation reaction to chemically modify negatively charged mesoporous silica under alkaline conditions. The subsequent two-stage programmed hydrogen annealing initiated the in situ formation of Au NPs and the reduction of α-Fe2O3to magnetic Fe, where the synthesized Au NPs were highly resistant to harsh thermal sintering even at 700 °C. Given its structural superiority and magnetic nature, the MFSVmS-Au was demonstrated to be a highly efficient and recoverable nanocatalyst with superior activity and reusability toward the reduction of 4-nitrophenol to 4-aminophenol, and the pristine morphology was retained after six recycling tests.
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Jiasheng
authors.identifier: 0000-0001-8515-8728
authors.initials: J
authors.lastname: Fang
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Zhao
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Sheng
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Jiangsu Optoelectronic Functional Materials and Engineering Laboratory , Nanjing 211189, P. R. China.
authors.forename: Kunpeng
authors.initials: K
authors.lastname: Wang