Better fuels for photocatalytic micromotors: a case study of triethanolamine.

Efficient fuels are critical for designing photocatalytic micromotors with high performance. We discover that 0.5 mM of triethanolamine can power TiO2-Pt motors at 35 μm s-1 without producing bubbles, a significant improvement over conventional fuels such as water, H2O2 or hydroquinone. The effectiveness of hole scavengers such as triethanolamine can be generalized to other photocatalytic micromotors containing a heterojunction with an n-type (but not a p-type) semiconductor.