2 research outputs found
Rapid and Efficient Self-Assembly of Au@ZnO CoreāShell Nanoparticle Arrays with an Enhanced and Tunable Plasmonic Absorption for Photoelectrochemical Hydrogen Generation
High-quality
Au@ZnO coreāshell nanoparticle (NP) array films were easily
and efficiently fabricated through an air/water interfacial self-assembly.
These materials have remarkable visible light absorption capacity
and fascinating performance in photoelectrochemical (PEC) water splitting
with a photocurrent density of ā¼3.08 mA/cm<sup>2</sup> at 0.4
V, which is superior to most ZnO-based photoelectrodes in studies.
Additionally, the interesting PEC performance could be effectively
adjusted by altering the thickness of the ZnO shell and/or the layer
number of the array films. Results indicated that the bilayer film
based on Au@ZnO NPs with 25 nm shell thickness displayed optimal behavior.
The remarkable PEC capability could be ascribed to the enhanced light-harvesting
ability of the Au@ZnO structured NPs by the SPR effect and the optimum
film thickness. This work demonstrates a desirable paradigm for preparing
photoelectrodes based on the synergistic effect of plasmatic NPs as
the core and a visible optical absorbent and semiconductor as the
shell. Moreover, this work provides a new approach for fabricating
optoelectronic anode thin film devices through a self-assembly method
Periodic Porous Alloyed AuāAg Nanosphere Arrays and Their Highly Sensitive SERS Performance with Good Reproducibility and High Density of Hotspots
Periodic
porous alloyed AuāAg nanosphere (NS) arrays with different
periodic lengths and tunable composition ratios were prepared on Si
substrates on a large scale (ā¼cm<sup>2</sup>) using stepwise
metal deposition-annealing and subsequent chemical corrosion from
a monolayer of colloidal polystyrene (PS) microspheres as the initial
template. The porous alloyed AuāAg NSs possessed a high porosity
and bicontinuous morphology composed of hierarchically interconnected
ligaments, which were obtained from an optimized dealloying process
in nitric acid. Interestingly, when the dealloying time was prolonged,
the average size of the porous alloyed NSs slightly decreased, and
the width of the ligaments gradually increased. The periodic length
of the array could be facilely changed by controlling the initial
particle size of the PS template. Moreover, the porous alloyed AuāAg
NS arrays were explored as a platform for the surface-enhanced Raman
scattering (SERS) detection of 4-aminothiophenol (4-ATP) and exhibited
excellent reproducibility and high sensitivity because of the periodic
structure of the arrays and the abundance of inherent āhotspotsā.
After optimization experiments, a low concentration of 10<sup>ā10</sup> M 4-ATP could be detected on these porous AuāAg NS array
substrates. Such highly reproducible SERS activity is meaningful for
improving the practical application of portable Raman detection equipment