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Light‐Driven Sandwich ZnO/TiO 2 /Pt Janus Micromotors: Schottky Barrier Suppression by Addition of TiO 2 Atomic Interface Layers into ZnO/Pt Micromachines Leading to Enhanced Fuel‐Free Propulsion
Author(s) -
Pourrahimi Amir Masoud,
Villa Katherine,
Sofer Zdeněk,
Pumera Martin
Publication year - 2019
Publication title -
small methods
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.66
H-Index - 46
ISSN - 2366-9608
DOI - 10.1002/smtd.201900258
Subject(s) - materials science , heterojunction , janus , photocatalysis , schottky barrier , nanotechnology , amorphous solid , ternary operation , optoelectronics , diode , chemistry , catalysis , biochemistry , organic chemistry , computer science , programming language
Conventional binary light‐driven micromotors, based on semiconducting photocatalysts and metal junctions, have mostly shown limited speed and charge separation/transport due to their not well‐designed interfaces. Here ZnO/Pt Janus micromotors with atomically smooth interfaces are introduced, which show fast light‐driven and fuel‐free propulsion (15 body‐length s −1 ). Furthermore, the speed of ZnO/Pt micromotors is increased by ≈60% with a few atomic amorphous TiO 2 photocatalyst interlayers. The new photocatalysts' interfaces, i.e., ZnO/TiO 2 , provide type II heterojunctions, leading to an increase in the number of electron/hole pairs and then improving the electron transfer to Pt metal. This effective charge separation/transfer results in a faster electrophoretic motion of the novel ternary ZnO/TiO 2 /Pt micromotors. The concept of the type II heterojunction, which is well known in photocatalysis communities, is used in light‐driven micromotors as a new approach and paves the way for the next‐generation of faster fuel‐free “green” micromotors.