Synergistic photothermal-bubbly driving effect on MnO2/carbon microsphere micromotors assisted by photocatalytic H2O2 decomposition

Micromotors with autonomous motion by multiple driving forces have attracted wide attentions. In this work, we successfully constructed MnO 2 -carbon microspheres (Mn-Cs) composite micromotors with synergistic photothermal-bubbly driving effect. The uniform MnO 2 loading and the stable combination of MnO 2 with Cs in Mn-Cs composite facilitated to improve the photothermal conversion performance. The regular morphology and large specific surface area of Mn-Cs were beneficial for the in-situ photocatalytic decomposition of H 2 O 2 under light irradiation. Notably, the photothermal conversion effect of Mn-Cs could further promote the decomposition of H 2 O 2 . The low thermal conductivity of air was beneficial for expanding the temperature gradient between the micromotor surface and the environment. As a result, the speed of optimal 1.0-Mn-Cs sample under the light irradiation and addition of H 2 O 2 (75.2 μm/s) was 14.3 and 5.88 times higher than that individual light irradiation (5.27 μm/s) and addition of H 2 O 2 (12.8 μm/s), respectively. It was indicative of the great significance of synergistic photothermal-bubbly driving effect. This study provided a new strategy for developing synergistically driven micromotors to reduce chemical fuel dependence, and showed a significant prospect in green, economic and sustainable applications.