Enhanced interfacial charge transfer between CsPbBr3 quantum dots and surface-modified TiO2/FTO photoanodes for photocurrent generation

Charge separation and charge transfer of electrode materials play an important factor to improve the photoelectrochemical (PEC) performance. In this work, the photocurrent generation via PEC oxidation of methanol was studied using surface-modified TiO2-coated fluorine-doped tin oxide (FTO) as a phot...

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Bibliographic Details
Published in:	Materials today. Nano Vol. 18; p. 100174
Main Authors:	Nuket, P., Akaishi, Y., Yoshimura, G., Vas-Umnuay, P., Kida, T.
Format:	Journal Article
Language:	English
Published:	Elsevier Ltd 01-06-2022
Subjects:	Cesium lead bromide Charge transfer Methanol Photoelectrochemical oxidation Surface-modified TiO2 Cesium lead bromide Photoelectrochemical oxidation Surface-modified TiO2 Charge transfer Methanol
Online Access:	Get full text
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Summary:	Charge separation and charge transfer of electrode materials play an important factor to improve the photoelectrochemical (PEC) performance. In this work, the photocurrent generation via PEC oxidation of methanol was studied using surface-modified TiO2-coated fluorine-doped tin oxide (FTO) as a photoanode in combination with CsPbBr3 quantum dots (QDs) dispersed in an electrolyte solution. Detailed studies revealed that surface modification of the TiO2 layer was crucial for good interfacial adhesion of CsPbBr3 QDs, which were surrounded by hydrophobic ligands, with the TiO2 surface. Self-assembled monolayers of octadecylphosphonic acid (ODPA) were applied on the TiO2 surface, resulting in the change of hydrophilic nature to a superhydrophobic surface. The photoluminescence measurement of the ODPA-modified TiO2/FTO photoanode demonstrated a significantly higher photoluminescence intensity than that of the unmodified one, indicating that CsPbBr3 QDs were well adsorbed on the TiO2 surface. The photocurrent was generated via methanol oxidation by holes in CsPbBr3 QDs. The current-voltage measurements revealed that in the presence of methanol, the current density was increased from 1.2 mA/cm2 (without methanol) to the maximum of 1.6 mA/cm2 under visible light irradiation, indicating that methanol was a sacrificial hole scavenger. Electrons in QDs were injected into the photoanode which led to enhanced charge separation and PEC performance. As a consequence, the multicomponent ODPA-modified TiO2/FTO photoanode in combination with CsPbBr3 QDs together with the efficient hole scavenger of methanol in the system has been shown to promote the PEC oxidation performance. [Display omitted] •CsPbBr3 quantum dots (QDs) serve as a charge generator and can transfer an electron to a photoanode.•Octadecylphosphonic acid -modified TiO2/fluorine-doped tin oxide photoanode provides hydrophobic interaction with CsPbBr3 QDs.•The good interaction between CsPbBr3 QDs and octadecylphosphonic acid -TiO2/fluorine-doped tin oxide improves charge transfer.•Methanol plays an important role as an efficient hole scavenger for CsPbBr3 QDs.•The photoanode with CsPbBr3 QDs achieves the photocurrent density of 2.2 mA/cm2.
ISSN:	2588-8420 2588-8420
DOI:	10.1016/j.mtnano.2022.100174