Light‐Driven Sandwich ZnO/TiO2/Pt Janus Micromotors: Schottky Barrier Suppression by Addition of TiO2 Atomic Interface Layers into ZnO/Pt Micromachines Leading to Enhanced Fuel‐Free Propulsion. Issue 11 (24th June 2019)

• Record Type: Journal Article
• Authors: Pourrahimi, Amir Masoud; Villa, Katherine; Sofer, Zdeněk; Pumera, Martin
• Is Part Of: Small methods. Volume 3:Issue 11(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-24
• Subjects: charge transport -- interfaces -- Janus micromotors -- light‐driven -- type II heterojunctions; Nanotechnology -- Methodology -- Periodicals; Nanotechnology -- Periodicals; Periodicals; 620.5028
• DOI: 10.1002/smtd.201900258
• Languages: English
• ISSNs: 2366-9608

Abstract

Abstract: 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 TiO2 photocatalyst interlayers. The new photocatalysts' interfaces, i.e., ZnO/TiO2, 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/TiO2 /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. Abstract : New light‐driven ZnO/TiO2 /Pt Janus micromotors with atomically smooth interfaces that are able to move faster than conventional ZnO/Pt are presented. The new ZnO/TiO2 type II heterojunction interfaces are here used for the first time in light‐driven micromotors to suppress the Schottky barrier resulting in a highly efficient charge transfer/separation and faster speed for heavy carriers.