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

74 Scopus citations

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
State	Published - 1 Feb 2018

UN SDGs

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

SDG 7 Affordable and Clean Energy

Keywords

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

Access to Document

10.1016/j.cej.2017.09.130

Cite this

@article{cbc937e642bc426591c0ea27e359310b,

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.\}",

note = "Publisher Copyright: {\textcopyright} 2017 Elsevier B.V.",

year = "2018",

month = feb,

day = "1",

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

language = "English",

volume = "333",

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journal = "Chemical Engineering Journal",

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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.

KW - Atomic layer deposition

KW - Bismuth vanadate nanopillar

KW - Heterostructure

KW - Photoanode

KW - Photocurrent density

KW - Water splitting

UR - https://www.scopus.com/pages/publications/85033457569

U2 - 10.1016/j.cej.2017.09.130

DO - 10.1016/j.cej.2017.09.130

M3 - Article

AN - SCOPUS:85033457569

SN - 1385-8947

VL - 333

SP - 721

EP - 729

JO - Chemical Engineering Journal

JF - Chemical Engineering Journal

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