2 research outputs found
Efficient Photocatalytic Hydrogen Generation from Ni Nanoparticle Decorated CdS Nanosheets
High-quality,
thickness-controlled CdS nanosheets (NSs) have been
obtained through the thermal decomposition of cadmium diethyldithiocarbamate
in octadecene. Ensembles with discrete thicknesses of 1.50, 1.80,
and 2.16 nm have been made with corresponding lateral dimensions on
the order of 90 nm × 20 nm. These latter values make the 1–3
nm NSs the largest 2D CdS specimens made to date using colloidal chemistry.
Associated Ni nanoparticle decorated counterparts have been made through
the photodeposition of Ni onto NSs with an average nanoparticle diameter
of 6 nm. Subsequent photocatalytic hydrogen generation measurements
have compared the performance of CdS NSs with that of their Ni NP
decorated counterparts in water/ethanol mixtures. Apparent quantum
yields as large as 25% have been seen for Ni NP decorated NSs with
transient yields as large as 64% within the first 2 h of irradiation.
Results from ensemble femtosecond transient differential absorption
spectroscopy reveal that the origin of this high efficiency stems
from efficient electron transfer from CdS to Ni. In this regard, the
CdS/Ni semiconductor/metal heterojunction acts to dissociate strongly
bound excitons in CdS NSs, creating free carriers needed to carry
out relevant reduction chemistries
Microwave-Assisted Solution–Liquid–Solid Synthesis of Single-Crystal Copper Indium Sulfide Nanowires
Chalcopyrite copper indium sulfide
(CuInS<sub>2</sub>) is an important
semiconductor with a bandgap optimal for terrestrial solar energy
conversion. Building photovoltaic and microelectronic devices using
one-dimensional CuInS<sub>2</sub> nanowires can offer directional
conduits for rapid and undisrupted charge transport. Currently, single-crystal
CuInS<sub>2</sub> nanowires can be prepared only using vapor-based
methods. Here, we report, for the first time, the synthesis of single-crystal
CuInS<sub>2</sub> nanowires using a microwave-assisted solution–liquid–solid
(MASLS) method. We show that CuInS<sub>2</sub> nanowires with diameters
of less than 10 nm can be prepared at a rapid rate of 33 nm s<sup>–1</sup> to more than 10 μm long in less than 10 min,
producing a high mass yield of 31%. We further show that the nanowires
are free of structural defects and have a near-stoichiometric composition.
The success of MASLS in preparing high-quality tertiary nanowires
is explained by a eutectic growth mechanism involving an overheated
alloy catalyst