Nanorods based on mesoporous silica containing iron oxide nanoparticles as catalytic nanomotors: study of motion dynamics

TL;DR

This study reports the fabrication of mesoporous silica nanorods with iron oxide nanoparticles that act as catalytic nanomotors, demonstrating different motion behaviors and potential applications in environmental and biomedical fields.

Contribution

It introduces a novel fabrication of mesoporous silica nanorods with integrated iron oxide nanoparticles for self-propulsion, exploring their motion dynamics and potential uses.

Findings

Nanorods exhibit two distinct motion types: enhanced diffusion and directional propulsion.

Motion is driven by catalytic decomposition of hydrogen peroxide using platinum and Fe2O3 catalysts.

Synergistic use of both catalysts enhances propulsion behavior.

Abstract

Self-propelled particles and, in particular, those based on mesoporous silica, have raised considerable interest due to their potential applications in the environmental and biomedical fields thanks to their biocompatibility, tunable surface chemistry and large porosity. Although spherical particles have been widely used to fabricate nano- and micromotors, not much attention has been paid to other geometries, such as nanorods. Here, we report the fabrication of self-propelled mesoporous silica nanorods (MSNRs) that move by the catalytic decomposition of hydrogen peroxide by a sputtered Pt layer, Fe2O3 nanoparticles grown within the mesopores, or the synergistic combination of both. We show that motion can occur in two distinct sub-populations characterized by two different motion dynamics, namely enhanced diffusion or directional propulsion, especially when both catalysts are used. These results open up the possibility of using MSNRs as chassis for the fabrication of self-propelled particles for the environmental or biomedical fields.