Enhanced Charge Carrier Separation in WO3/BiVO4Photoanodes Achieved via Light Absorption in the BiVO4Layer

Ivan Grigioni; Annalisa Polo; Maria Vittoria Dozzi; Kevin G. Stamplecoskie; Danilo H. Jara; Prashant V. Kamat; Elena Selli

doi:10.1021/acsaem.2c02597

Enhanced Charge Carrier Separation in WO₃/BiVO₄Photoanodes Achieved via Light Absorption in the BiVO₄Layer

Ivan Grigioni, Annalisa Polo, Maria Vittoria Dozzi, Kevin G. Stamplecoskie, Danilo H. Jara, Prashant V. Kamat, Elena Selli

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

13 Scopus citations

Abstract

Photoelectrochemical (PEC) water splitting converts solar light and water into oxygen and energy-rich hydrogen. WO₃/BiVO₄heterojunction photoanodes perform much better than the separate oxide components, though internal charge recombination undermines their PEC performance when both oxides absorb light. Here we exploit the BiVO₄layer to sensitize WO₃to visible light and shield it from direct photoexcitation to overcome this efficiency loss. PEC experiments and ultrafast transient absorption spectroscopy performed by frontside (through BiVO₄) or backside (through WO₃) irradiating photoanodes with different BiVO₄layer thickness demonstrate that irradiation through BiVO₄is beneficial for charge separation. Optimized electrodes irradiated through BiVO₄show 40% higher photocurrent density compared to backside irradiation.

Original language	English
Pages (from-to)	13142-13148
Number of pages	7
Journal	ACS Applied Energy Materials
Volume	5
Issue number	11
DOIs	https://doi.org/10.1021/acsaem.2c02597
State	Published - 28 Nov 2022
Externally published	Yes

Keywords

filter effect
heterojunction
photoactive layer thickness
solar water oxidation
ultrafast transient absorption

Access to Document

10.1021/acsaem.2c02597

Cite this

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title = "Enhanced Charge Carrier Separation in WO3/BiVO4Photoanodes Achieved via Light Absorption in the BiVO4Layer",

abstract = "Photoelectrochemical (PEC) water splitting converts solar light and water into oxygen and energy-rich hydrogen. WO3/BiVO4heterojunction photoanodes perform much better than the separate oxide components, though internal charge recombination undermines their PEC performance when both oxides absorb light. Here we exploit the BiVO4layer to sensitize WO3to visible light and shield it from direct photoexcitation to overcome this efficiency loss. PEC experiments and ultrafast transient absorption spectroscopy performed by frontside (through BiVO4) or backside (through WO3) irradiating photoanodes with different BiVO4layer thickness demonstrate that irradiation through BiVO4is beneficial for charge separation. Optimized electrodes irradiated through BiVO4show 40% higher photocurrent density compared to backside irradiation.",

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author = "Ivan Grigioni and Annalisa Polo and Dozzi, {Maria Vittoria} and Stamplecoskie, {Kevin G.} and Jara, {Danilo H.} and Kamat, {Prashant V.} and Elena Selli",

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T1 - Enhanced Charge Carrier Separation in WO3/BiVO4Photoanodes Achieved via Light Absorption in the BiVO4Layer

AU - Grigioni, Ivan

AU - Polo, Annalisa

AU - Dozzi, Maria Vittoria

AU - Stamplecoskie, Kevin G.

AU - Jara, Danilo H.

AU - Kamat, Prashant V.

AU - Selli, Elena

PY - 2022/11/28

Y1 - 2022/11/28

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AB - Photoelectrochemical (PEC) water splitting converts solar light and water into oxygen and energy-rich hydrogen. WO3/BiVO4heterojunction photoanodes perform much better than the separate oxide components, though internal charge recombination undermines their PEC performance when both oxides absorb light. Here we exploit the BiVO4layer to sensitize WO3to visible light and shield it from direct photoexcitation to overcome this efficiency loss. PEC experiments and ultrafast transient absorption spectroscopy performed by frontside (through BiVO4) or backside (through WO3) irradiating photoanodes with different BiVO4layer thickness demonstrate that irradiation through BiVO4is beneficial for charge separation. Optimized electrodes irradiated through BiVO4show 40% higher photocurrent density compared to backside irradiation.

KW - filter effect

KW - heterojunction

KW - photoactive layer thickness

KW - solar water oxidation

KW - ultrafast transient absorption

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