Electrosprayed BiVO4 nanopillars coated with atomic-layer-deposited ZnO/TiO2 as highly efficient photoanodes for solar water splitting

Min Woo Kim; Karam Kim; Tae Yoon Ohm; Hyun Yoon; Bhavana Joshi; Edmund Samuel; Mark T. Swihart; Sung Kyu Choi; Hyunwoong Park; Sam S. Yoon

doi:10.1016/j.cej.2017.09.130

Electrosprayed BiVO₄ nanopillars coated with atomic-layer-deposited ZnO/TiO₂ as highly efficient photoanodes for solar water splitting

Min Woo Kim, Karam Kim, Tae Yoon Ohm, Hyun Yoon, Bhavana Joshi, Edmund Samuel, Mark T. Swihart, Sung Kyu Choi, Hyunwoong Park, Sam S. Yoon

Research output: Contribution to journal › Article › peer-review

69 Citations (Scopus)

Abstract

We report the fabrication and the performance in photoelectrochemical water splitting of thin films of electrostatically sprayed nanotextured bismuth vanadate (BiVO₄) pillars coated with thin ZnO/TiO₂ passivation layers formed by atomic layer deposition. The thin ZnO and TiO₂ layers deposited on the BiVO₄ nanopillars formed a heterostructure that promoted electron–hole separation and the migration of electrons toward the ITO substrate. The photocurrent density (PCD) of the ZnO/TiO₂ coated BiVO₄ was 2.5 times higher (2.25 mA/cm² at 1.2 V (versus Ag/AgCl)) than that of pristine BiVO₄ (0.9 mA/cm² at 1.2 V (versus Ag/AgCl)). We present incident/absorbed photon-to-current efficiency and electrochemical impedance measurements confirming that this improvement is a result of the heterojunction produced by the conformal ZnO/TiO₂ coating and discuss the mechanism of this dramatic enhancement of PCD.

Original language	English
Pages (from-to)	721-729
Number of pages	9
Journal	Chemical Engineering Journal
Volume	333
DOIs	https://doi.org/10.1016/j.cej.2017.09.130
Publication status	Published - 2018 Feb 1

Bibliographical note

Publisher Copyright:
© 2017 Elsevier B.V.

Keywords

Atomic layer deposition
Bismuth vanadate nanopillar
Heterostructure
Photoanode
Photocurrent density
Water splitting

ASJC Scopus subject areas

General Chemistry
Environmental Chemistry
General Chemical Engineering
Industrial and Manufacturing Engineering

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.cej.2017.09.130

Cite this

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title = "Electrosprayed BiVO4 nanopillars coated with atomic-layer-deposited ZnO/TiO2 as highly efficient photoanodes for solar water splitting",

abstract = "We report the fabrication and the performance in photoelectrochemical water splitting of thin films of electrostatically sprayed nanotextured bismuth vanadate (BiVO4) pillars coated with thin ZnO/TiO2 passivation layers formed by atomic layer deposition. The thin ZnO and TiO2 layers deposited on the BiVO4 nanopillars formed a heterostructure that promoted electron–hole separation and the migration of electrons toward the ITO substrate. The photocurrent density (PCD) of the ZnO/TiO2 coated BiVO4 was 2.5 times higher (2.25 mA/cm2 at 1.2 V (versus Ag/AgCl)) than that of pristine BiVO4 (0.9 mA/cm2 at 1.2 V (versus Ag/AgCl)). We present incident/absorbed photon-to-current efficiency and electrochemical impedance measurements confirming that this improvement is a result of the heterojunction produced by the conformal ZnO/TiO2 coating and discuss the mechanism of this dramatic enhancement of PCD.",

keywords = "Atomic layer deposition, Bismuth vanadate nanopillar, Heterostructure, Photoanode, Photocurrent density, Water splitting",

author = "Kim, {Min Woo} and Karam Kim and Ohm, {Tae Yoon} and Hyun Yoon and Bhavana Joshi and Edmund Samuel and Swihart, {Mark T.} and Choi, {Sung Kyu} and Hyunwoong Park and Yoon, {Sam S.}",

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doi = "10.1016/j.cej.2017.09.130",

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T1 - Electrosprayed BiVO4 nanopillars coated with atomic-layer-deposited ZnO/TiO2 as highly efficient photoanodes for solar water splitting

AU - Kim, Min Woo

AU - Kim, Karam

AU - Ohm, Tae Yoon

AU - Yoon, Hyun

AU - Joshi, Bhavana

AU - Samuel, Edmund

AU - Swihart, Mark T.

AU - Choi, Sung Kyu

AU - Park, Hyunwoong

AU - Yoon, Sam S.

PY - 2018/2/1

Y1 - 2018/2/1

N2 - We report the fabrication and the performance in photoelectrochemical water splitting of thin films of electrostatically sprayed nanotextured bismuth vanadate (BiVO4) pillars coated with thin ZnO/TiO2 passivation layers formed by atomic layer deposition. The thin ZnO and TiO2 layers deposited on the BiVO4 nanopillars formed a heterostructure that promoted electron–hole separation and the migration of electrons toward the ITO substrate. The photocurrent density (PCD) of the ZnO/TiO2 coated BiVO4 was 2.5 times higher (2.25 mA/cm2 at 1.2 V (versus Ag/AgCl)) than that of pristine BiVO4 (0.9 mA/cm2 at 1.2 V (versus Ag/AgCl)). We present incident/absorbed photon-to-current efficiency and electrochemical impedance measurements confirming that this improvement is a result of the heterojunction produced by the conformal ZnO/TiO2 coating and discuss the mechanism of this dramatic enhancement of PCD.

AB - We report the fabrication and the performance in photoelectrochemical water splitting of thin films of electrostatically sprayed nanotextured bismuth vanadate (BiVO4) pillars coated with thin ZnO/TiO2 passivation layers formed by atomic layer deposition. The thin ZnO and TiO2 layers deposited on the BiVO4 nanopillars formed a heterostructure that promoted electron–hole separation and the migration of electrons toward the ITO substrate. The photocurrent density (PCD) of the ZnO/TiO2 coated BiVO4 was 2.5 times higher (2.25 mA/cm2 at 1.2 V (versus Ag/AgCl)) than that of pristine BiVO4 (0.9 mA/cm2 at 1.2 V (versus Ag/AgCl)). We present incident/absorbed photon-to-current efficiency and electrochemical impedance measurements confirming that this improvement is a result of the heterojunction produced by the conformal ZnO/TiO2 coating and discuss the mechanism of this dramatic enhancement of PCD.

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KW - Bismuth vanadate nanopillar

KW - Heterostructure

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