Fabrication of Fe3O4/SiO2 core–shell nanoparticle monolayer as catalyst for carbon nanotube growth using Langmuir–Blodgett technique

In this work, an approach of controllable distance of catalytic nanoparticles (NPs) shrouded in shell layer for carbon nanotube (CNT) growth has been developed with the aid of the Langmuir–Blodgett (LB) technique. Coagulation of core–shell NPs was controlled by the surface pressure of the LB technique. Scanning electron microscope images show that core–shell NP LB film without coagulation and vacancies was observed. The approach of core–shell NP LB film revealed in this work could potentially be applied in catalytic NP monolayer formation and high activity of catalytic NPs for CNT growth. •Fe3O4 nanoparticles (NPs) and Fe3O4/SiO2 core–shell NPs were synthesized.•Fe3O4 NP as catalyst was almost retained at the center of SiO2 shell structure.•Core–shell NP monolayer without coagulation and vacancies was deposited on substrate.•Core–shell NP monolayer was closely packed by using Langmuir–Blodgett technique.