Enabling synchronous activation of inner-core and mesoporous outer-shell of monodispersed Fe3O4@SiO2 by in-situ implanted MnOx to synergistically deliver enhanced catalytic activity

Herein, we report a facile synthetic method enabling the synchronously activated decoration of the inner core and mesoporous outer shell of monodispersed Fe3O4@meso-silica using in situ implanted MnOx. This approach can maintain the catalytic activity of the internal core without loss of its inherent magnetic properties even when undergoing calcination. The developed catalyst exhibits a well-defined core-shell configuration with a MnOx coating on an Fe3O4 internal core and a MnOx-modified mesoporous outer shell, obtained via only a one-pot output cycle. The thin MnOx coating layer prevents excess oxidation of the unoxidized Fe3O4 core during the annealing process. Additionally, the mesopores in the coated silica were synchronously functionalized by the assistance of dodecylamine (DDA) as surfactant because of the coordination effect of Mn2+ and DDA molecules. The optimal nanocatalyst exhibits improved catalytic activity for styrene oxidation and recoverability due to its magnetic-responsive properties, in contrast to postsynthesized and shell-only functionalized catalysts. (C) 2020 Elsevier B.V. All rights reserved.