Controllable growth of ZIF-8 layers with nanometer-level precision on SiO2 nano-powders via liquid phase epitaxy stepwise growth approach

Abstract Engineering the growth of MOFs on substrates at the nanometer or even the molecular level is of major interest for taking MOFs beyond their uses as bulk materials and creating multifunctional features with advanced applications. Herein we report the SiO 2 @ZIF-8 (core@shell) monodisperse nanospheres synthesized through a liquid-phase epitaxy stepwise growth (LPE) strategy. The controlled growth of ZIF-8 shell with nanometer-level precision could be achieved. The growth of the ZIF-8 shell can be adjusted by manipulating the influencing factors, such as growth circles, precursor solvent, precursor concentration, core size, synthesis temperature and implementation methods. The formation processes of ZIF-8 shell on the SiO 2 surface using different precursor solvents were also deduced. The composite exhibited faster adsorption for bisphenol A with ultra-high adsorption capacity per unit ares compared to ZIF-8-only material. Such controlled growth of homogeneous ZIF-8 shell with nanometer-level precision is of paramount importance for the success of fabricating ZIFs layers in the channels ofmesoporous materialics. Further, this paves the way for integrated MOF materials to address a wide range of challenges in the areas of catalysis, rapid detection, adsorption and separation.