fulltext.study @t Gmail

Size-dependent performance of CdSe quantum dots in the photocatalytic evolution of hydrogen under visible light irradiation

Paper ID Volume ID Publish Year Pages File Format Full-Text
39000 45800 2016 5 PDF Available
Title
Size-dependent performance of CdSe quantum dots in the photocatalytic evolution of hydrogen under visible light irradiation
Abstract

•Cadmium selenide quantum dots with size-dependent light absorption features act as efficient photocatalysts in hydrogen production from water solutions.•The quantum efficiency in photocatalytic hydrogen production is not dominated exclusively by the photocatalyst conduction band position.•An optimum 2.8 nm size is a good compromise between good visible light harvesting capability, suitable conduction band position and low probability of photoproduced charge transfer recombination.

Nanocrystalline materials are widely employed as photocatalysts for water splitting applications. In particular, cadmium selenide quantum dots (QDs) attracted growing interest for their superior photon to H2 conversion efficiency and their stability under irradiation. A direct insight is here presented on the effects that CdSe QDs size has on their photoactivity in hydrogen evolution from Na2SO3—containing aqueous solutions under visible light irradiation. Four highly monodisperse CdSe quantum dots with different nanocrystal diameters were synthesized and, after exchange of the capping ligand, employed as photocatalyst in H2 production in the absence of any co-catalyst. Their size-dependent photocatalytic activity is discussed in relation to their absorption properties, their conduction band energy and the recombination probability of the photogenerated charges inside the nanocrystals. High quantum efficiency in H2 generation results from a balance among these three QDs features, their activity scale being not exclusively dominated by the photocatalyst conduction band position.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (116 K)Download as PowerPoint slide

Keywords
Photocatalytic hydrogen production; Quantum dots; Cadmium selenide; Visible light; Solar fuels
First Page Preview
Size-dependent performance of CdSe quantum dots in the photocatalytic evolution of hydrogen under visible light irradiation
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 518, 25 May 2016, Pages 176–180
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis