Issue 2, 2015

Ultrafast exciton quenching by energy and electron transfer in colloidal CdSe nanosheet–Pt heterostructures

Abstract

Two-dimensional (2-D) semiconductor nanomaterials are receiving tremendous research interests due in part to their attractive light absorption and charge transport properties. Integration of catalytic metal nanoparticles with these 2-D semiconductors can potentially lead to new photocatalytic nanoheterostructures for efficient solar-to-fuel conversion. Here we report the synthesis and transient absorption study of colloidal quantum confined CdSe nanosheets with a Pt nanoparticle at the edge or vertex. Due to the large in-plane exciton mobility, ∼86.6 ± 0.5% of excitons generated in CdSe sheets can be transported to NS–Pt interface and quenched by energy transfer to Pt (with a half-life <150 fs). The remaining excitons (13.4 ± 0.5%) become localized due to fast hole trapping and can be dissociated by interfacial electron transfer to Pt (with a half life of ∼9.4 ± 0.7 ps). The resulting charge-separated states (with electrons in Pt and trapped holes in CdSe) are long-lived (half life of ∼75 ± 14 ns), suggesting possible applications for solar driven H2 generation.

Graphical abstract: Ultrafast exciton quenching by energy and electron transfer in colloidal CdSe nanosheet–Pt heterostructures

Supplementary files

Article information

Article type
Edge Article
Submitted
28 Sep 2014
Accepted
04 Nov 2014
First published
04 Nov 2014
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2015,6, 1049-1054

Author version available

Ultrafast exciton quenching by energy and electron transfer in colloidal CdSe nanosheet–Pt heterostructures

K. Wu, Q. Li, Y. Du, Z. Chen and T. Lian, Chem. Sci., 2015, 6, 1049 DOI: 10.1039/C4SC02994A

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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