Triangular and Prism‐Shaped Gold‐Zinc Oxide Plasmonic Nanostructures: In situ Reduction, Assembly, and Full‐Range Photocatalytic Performance

Abstract

Gold-based nanocatalysts have been traditionally selected for multiple homogeneous and heterogeneous reactions of interest involving redox processes. Likewise, greener routes involving more efficient reactors and the use of inexpensive and nature-mimicking excitation sources have boosted the research on photocatalysts that can drive these chemical reactions upon excitation with multiple wavelength sources beyond the UV range. In the present work we report on a multi-step synthesis approach that enables the in situ generation of triangular and prism-shaped gold nanostructures with a localized surface plasmon resonance effect and their direct assembly onto a ZnO nanostructured semiconductor support. Different [a]

Silver-Copper Oxide Heteronanostructures for the Plasmonic-Enhanced Photocatalytic Oxidation of N-Hexane in the Visible-NIR Range

“…The experimental setup designed to carry out the photocatalytic degradation of n-hexane has been previously described elsewhere [20,122]. Briefly, the reaction was conducted in a home-made system comprising a quartz cell (50 × 10 × 5 mm 3 (height × width × length).…”

Anisotropic Au-ZnO photocatalyst for the visible-light expanded oxidation of n-hexane

“…The synthesis of the Au-ZnO was carried out as described elsewhere [35,62]. The standard procedure can be briefly described as follows: in the first place, 1g of ZnO was dispersed in 40…”

“…This red-shift can be attributed to the absorption capabilities of Au nanostructures [26] and their plasmonic behaviour [57]. The variety of sizes and shapes (triangles and prisms) [62] induces changes in the electromagnetic field at the surface of the NPs and a shift in the oscillation frequencies of the conduction electrons [28,65,73]. At the end, an almost continuous absorption band is measured as a combination of all these modifications in the Au nanostructures ( Figure 1e).…”

“…For these reasons, recent studies have explored the synergetic combination of plasmonic Au and ZnO structures to form metal-semiconductor heterojunctions [39,[50][51][52][53][54][55][56][57][58]. Au-ZnO hybrids with different shapes and configurations have been systematically investigated and preferentially applied to UV-visible-expanded photocatalytic degradation of organic pollutants or model dyes in liquid media [39,52,[56][57][58][59][60][61][62]. Furthermore, these Au-ZnO J o u r n a l P r e -p r o o f composites have been also successfully tested in photo-assisted gas phase reactions for sensing [63], hydrogen production [64] or CO2 hydrogenation [65].…”

Metal/semiconductor interfaces in nanoscale objects: synthesis, emerging properties and applications of hybrid nanostructures

“…4-NP reduction was demonstrated with triangularand prism-shaped Au domains/ZnO HNSs, prepared in an aqueous phase. 341 Epitaxial Au-triangular ZnO NPs (and Pt-Au-ZnO) were used to study the charge accumulation and discharge using degradation of toluidine blue, which allowed monitoring not only degradation (photoreduction) but also measuring on/ off characteristics due to its ability to reoxidize. 64 As these examples show, a metal domain is benecial for dye degradation since it attracts photoexcited electrons, and then these electrons may generate hydroxyl and superoxide radicals, which then attack the dyes.…”