Internally/Externally Bubble-Propelled Photocatalytic Tubular Nanomotors for Efficient Water Cleaning

We
describe a highly effective bubble-propelled nanomotor for the photocatalytic
decomposition of organic pollutants in water. Two different tubular
TiO2 nanomotor systems are presented: one with Pt nanoparticles
decorated on the inner surface and the other with Pt nanoparticles
decorated on the outer surface. This is the first time that we have
observed the autonomous movement of a tubular nanomotor without the
aid of any surfactant, as well as a tubular nanomotor externally decorated
with Pt propelled by oxygen bubbles. The synergy between the Pt nanoparticles
and the superhydrophilic wetting behavior of the TiO2 nanotubes
endows the two nanomotor systems with high speed at very low H2O2 fuel concentrations without the addition of
any surfactant. The efficient photodecomposition of rhodamine B demonstrates
the intermixing and photocatalytic ability of the two nanomotor systems,
which opens new avenues for the development of multifunctional bubble-propelled
micro/nanomotors with myriad practical applications.