Reversing a Platinum Micromotor by Introducing Platinum Oxide

Abstract Understanding and controlling the swimming direction of a synthetic nano‐ micromotor holds fundamental applied significance. Here, we focus on platinum‐containing Janus colloids that catalytically decompose H 2 O into , an archetypical model chemical micromotor. We discover platinum oxides (primarily PtO) are produced Pt films sputter‐coated in plasma, PtO reverses motor possibly by self‐electrophoresis. Using this knowledge, micromotors moving either were fabricated intentionally introducing or removing PtO. These findings challenge conventional wisdom is powered alone, open up new avenues for directions micro‐ nanomachine.