ZnO Coated Anodic 1D TiO2 Nanotube Layers: Efficient Photo-Electrochemical and Gas Sensing Heterojunction

Ng SW, Kubersky P, Krbal M, Prikryl J, Gartnerova V, Moravcova D, Sopha H, Zazpe R, Yam FK, Jager A, Hromadko L, Benes L, Hamacek A, Macak JM (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Advanced Engineering Materials Wiley

Book Volume: 20

Article Number: 1700589

Journal Issue: 2

DOI: 10.1002/adem.201700589

Abstract

The authors demonstrate, in this work, a fascinating synergism of a high surface area heterojunction between TiO2 in the form of ordered 1D anodic nanotube layers of a high aspect ratio and ZnO coatings of different thicknesses, produced by atomic layer deposition. The ZnO coatings effectively passivate the defects within the TiO2 nanotube walls and significantly improve their charge carrier separation. Upon the ultraviolet and visible light irradiation, with an increase of the ZnO coating thickness from 0.19 to 19 nm and an increase of the external potential from 0.4–2 V, yields up to 8-fold enhancement of the photocurrent density. This enhancement translates into extremely high incident photon to current conversion efficiency of ≈95%, which is among the highest values reported in the literature for TiO2 based nanostructures. In addition, the photoactive region is expanded to a broader range close to the visible spectral region, compared to the uncoated nanotube layers. Synergistic effect arising from ZnO coated TiO2 nanotube layers also yields an improved ethanol sensing response, almost 11-fold compared to the uncoated nanotube layers. The design of the high-area 1D heterojunction, presented here, opens pathways for the light- and gas-assisted applications in photocatalysis, water splitting, sensors, and so on.

Authors with CRIS profile

Siow Woon Ng

Involved external institutions

University of Pardubice CZ Czech Republic (CZ) University of West Bohemia (UWB) CZ Czech Republic (CZ) Institute of Physics of the Czech Academy of Sciences / Fyzikální ústav Akademie věd České republiky (FZU) CZ Czech Republic (CZ) University of Science Malaysia (USM) / Universiti Sains Malaysia MY Malaysia (MY)

How to cite

APA:

Ng, S.W., Kubersky, P., Krbal, M., Prikryl, J., Gartnerova, V., Moravcova, D.,... Macak, J.M. (2018). ZnO Coated Anodic 1D TiO2 Nanotube Layers: Efficient Photo-Electrochemical and Gas Sensing Heterojunction. Advanced Engineering Materials, 20(2). https://doi.org/10.1002/adem.201700589

MLA:

Ng, Siow Woon, et al. "ZnO Coated Anodic 1D TiO2 Nanotube Layers: Efficient Photo-Electrochemical and Gas Sensing Heterojunction." Advanced Engineering Materials 20.2 (2018).

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