TY - JOUR
T1 - Simple growth of faceted Au-ZnO hetero-nanostructures on silicon substrates (nanowires and triangular nanoflakes)
T2 - A shape and defect driven enhanced photocatalytic performance under visible light
AU - Ghosh, Arnab
AU - Guha, Puspendu
AU - Samantara, Aneeya K.
AU - Jena, Bikash Kumar
AU - Bar, Rajshekhar
AU - Ray, Samit
AU - Satyam, Parlapalli V.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/5/13
Y1 - 2015/5/13
N2 - 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 on 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 (Rct) 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-1, which is ≈5.3 times higher compared to NWs case with 0.0058 min-1. 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.
AB - 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 on 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 (Rct) 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-1, which is ≈5.3 times higher compared to NWs case with 0.0058 min-1. 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.
KW - dye degradation
KW - hetero-nanostructures
KW - oxygen defects
KW - photocatalyst
KW - photoelectrochemistry
KW - triangular nanoflakes
UR - http://www.scopus.com/inward/record.url?scp=84929379644&partnerID=8YFLogxK
U2 - 10.1021/acsami.5b00634
DO - 10.1021/acsami.5b00634
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AN - SCOPUS:84929379644
SN - 1944-8244
VL - 7
SP - 9486
EP - 9496
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 18
ER -