Hybrid Integration of Au Nanoplates and Ag Nanoparticles with Controlled Nanogaps via Cu₂O‐mediated Galvanic Replacement Reaction: Plasmonic Catalysis and Photothermal Conversion

Abstract

Rational assembling of different noble metal nanocrystals with controlled nanogaps in one entity allows the efficient coupling of electromagnetic fields of each component and versatile manipulation over the overall physiochemical properties. In the present study, we report a stepwise synthetic strategy to hybridlike assemble Au nanoplate and Ag nanoparticles without direct physical contact. Particularly, the success of current work relies on the conformal coating of Cu2O over the Au nanoplate as an intermediate layer, followed by the in situ formation of Ag nanoparticles via the galvanic replacement reaction between Cu2O and Ag+. With the anchoring of Ag nanoparticles over the Cu2O‐wrapped Au nanoplate, the resulting hybrid nanostructures exhibit noticeable multiple plasmonic absorptions across the UV‐vis‐NIR region. The potential use as the plasmonic catalyst for current Au@Cu2O‐Ag hybrid products is validated using reduction of 4‐nitrophenol as the model reaction, where the catalytic performance is greatly improved by the UV‐vis light irradiation. They also exhibit satisfactory photothermal conversion performance under the irradiation of Xe lamp. The current work provides a niche strategy to create noble‐metal hybrid nanostructures with controlled interparticle distance and tunable plasmonic properties, could be extended to other noble metal or alloys.

One-Pot Growth of Dual-Semiconductor Coshells on Au Nanorods with Tunable Band Arrangements for Efficient Photocatalysis

“…In a typical metal–semiconductor core–shell hybrids, the metal cores usually are Au, Ag, or Cu nanocrystals. − Various kinds of semiconductor shells have been grown on the metal cores, such as metal oxides (TiO 2 , ZnO, Cu 2 O, CeO 2 ), − binary chalcogenides (CdS, PbS, CdSe), − and ternary chalcogenides (AuAgS, AgZnSnS, CuInS 2 ). , Although the meta@semiconductor core–shell hybrids have been proven to show higher photocatalytic performance than bare semiconductors, the final photoactivity still has room for improvement. Semiconductor heterojunctions, in which two different semiconductors are integrated together, are widely studied in photocatalytic energy conversion. − The combination of semiconductors with different bandgaps can not only greatly extend the light response range but also form a built-in electric field to enhance charge separation of the photogenerated carriers, further improving the photocatalytic efficiency. , Z-scheme, straddling-gap (type I), and staggered-gap junctions (type II) are the most studied semiconductor heterojunctions. − The combination of semiconductor junctions with metal cores can further improve the photocatalytic activity owing to plasmonic absorption and plasmon-mediated charge transfer.…”