Ultrasmall Pt NPs-modified flasklike colloidal motors with high mobility and enhanced ion tolerance

Abstract

Chemically powered colloidal motors propelled by the self-phoretic effect have attracted widespread attention. However, the low motion efficiency and ion tolerance hinder their application in complex media. Herein, we report a scalable and simple method to synthesize 2.6 nm Platinum nanoparticles (Pt NPs) in the nanoporous wall of carbonaceous flasklike colloidal motors in a ligand-free manner. The obtained Pt NPs-modified flasklike colloidal motors (Pt-FCMs) are propelled by the catalytic decomposition of H₂O₂ fuels. They exhibit ultrafast mobility with an instantaneous velocity of 134 μm s⁻¹ at 5% H₂O₂, which is equivalent to 180 bodylengths per second. Particularly, these Pt-FCMs have an enhanced ion tolerance, due to the higher catalytic activity of small-sized Pt NPs in the carbonaceous wall. Furthermore, the direction of motion could be reversed by adding cationic surfactant cetyltrimethylammonium bromide. Such ultrasmall Pt NPs funtionalized flasklike colloidal motors exhibit a great potential utilization in the field of biomedicines and environmental technology.