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E-mail: tlian@emory.edu

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Research Funding:

We gratefully acknowledge the financial support from the National Science Foundation (CHE-1309817).

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

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Journal Title:

Chemical Science

Volume:

Volume 6, Number 2

Publisher:

, Pages 1049-1054

Type of Work:

Article | Final Publisher PDF

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 H 2 generation.

Copyright information:

© The Royal Society of Chemistry 2015.

This is an Open Access work distributed under the terms of the Creative Commons Attribution 3.0 Unported License (http://creativecommons.org/licenses/by/3.0/).

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