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High-Efficiency Plasmon-Enhanced and Graphene-Supported Semiconductor/Metal Core–Satellite Hetero-Nanocrystal Photocatalysts for Visible-Light Dye Photodegradation and H2 Production from Water
journal contribution
posted on 2014-11-26, 00:00 authored by Jie Zhang, Ping Wang, Jian Sun, Yongdong JinSolar-driven photocatalytic process
based on electron–hole
pair production in semiconductors is a long sought-after solution
to a green and renewable energy and has attracted a renaissance of
interest recently. The relatively low photocatalytic efficiency, however,
is a main obstacle to their practical applications. A promising attempt
to solve this problem is by combined use of metal nanoparticles, by
taking advantage of strong and localized plasmonic near-field to enhance
solar absorption and to increase the electron–hole pair generation
rate at the surface of semiconductor. Here, we report a semiconductor/metal
visible-light photocatalyst based on CdSe/CdS-Au (QD-Au) core–satellite
heteronanocrystals, and assemble them on graphene nanosheets for better
photocatalytic reaction. The as-synthesized photocatalyst exhibits
excellent plasmon-enhanced photocatalytic activities toward both photodegradation
of organic dye and visible-light H2 generation from water.
The H2 evolution rate achieves a maximum of 3113 μmol
h–1 g–1 for the heteronanocrystal-graphene
composites, which is about 155% enhancement compared to nonplasmonic
QD-G sample and 340% enhancement compared to control QD-Au-G sample,
and the apparent quantum efficiency (QE) reaches to 25.4% at wavelength
of 450 nm.