1 research outputs found
Simple Growth of Faceted Au–ZnO Hetero-nanostructures on Silicon Substrates (Nanowires and Triangular Nanoflakes): A Shape and Defect Driven Enhanced Photocatalytic Performance under Visible Light
A simple
single-step chemical vapor deposition (CVD) method has been used to
grow the faceted Au–ZnO hetero-nanostructures (HNs) either
with nanowires (NWs) or with triangular nanoflakes (TNFs) on crystalline
silicon wafers with varying oxygen defect density in ZnO nanostructures.
This work reports on the use of these nanostructures <i>on</i> substrates for photodegradation of rhodamine B (RhB) dyes and phenol
under the visible light illumination. The photoluminescence measurements
showed a substantial enhancement in the ratio of defect emission to
band-edge emission for TNF (ratio ≈ 7) compared to NW structures
(ratio ≤ 0.4), attributed to the presence of more oxygen defects
in TNF sample. The TNF structures showed 1 order of magnitude enhancement
in photocurrent density and an order of magnitude less charge-transfer
resistance (<i>R</i><sub>ct</sub>) compared to NWs resulting
high-performance photocatalytic activity. The TNFs show enhanced photocatalytic
performance compared to NWs. The observed rate constant for RhB degradation
with TNF samples is 0.0305 min<sup>–1</sup>, which is ≈5.3
times higher compared to NWs case with 0.0058 min<sup>–1</sup>. A comparison has been made with bulk ZnO powders and ZnO nanostructures
without Au to deduce the effect of plasmonic nanoparticles (Au) and
the shape of ZnO in photocatalytic performance. The results reveal
the enhanced photocatalytic capability for the triangular nanoflakes
of ZnO toward RhB degradation with good reusability that can be attracted
for practical applications