Pt-Free microengines at extremely low peroxide levels

Abstract

Herein, we demonstrate that iron oxide modified MnO₂ (FeO_x–MnO₂) catalyzed micromotors can be fabricated via electrochemical co-reduction and exhibit exceptional high performance at an extremely low hydrogen peroxide (H₂O₂) fuel concentration. We observed that graphene/FeO_x–MnO₂ microtubes could show motion behaviors at fuel concentration as low as 0.03% H₂O₂, which is nearly one order of magnitude lower than Pt-based micromotors (normally at above 0.2% H₂O₂). Moreover, the micromotors exhibit higher speeds than any other reported catalytic micro/nanomotors (MNMs) at low peroxide levels. The FeO_x–MnO₂ systems are better catalytic MNMs, due to their excellent catalytic activity, easy fabrication, robust structure and movement, as well as low-cost, biocompatible and abundance nature, showing great potential for future applications.