Synthesis of porous Ag-Ag2S@Ag-Au hybrid nanostructures with broadband absorption properties and their photothermal conversion application

Hybrid nanostructures composed of a plasmonic noble metal and a semiconductor have been studied intensively because of their unusual properties and wide range of potential applications. However, preparing these hybrid nanostructures with a precisely controlled shape, composition, heterostructure, and internal structure remains a challenge. Here, we describe a method for synthesizing new metal-semiconductor@ bimetal hybrid nanostructures. Specifically, Ag-Ag2S nanoplates were first prepared by site-controlled sulfidation, and these nanoplates were then used as seeds to synthesize Ag-Ag2S@Ag-Au hybrid nanostructures with unique porous architectures through seed-mediated growth and a galvanic replacement reaction. The composition of the ternary alloy combined with the unique porous structure of the hybrid nanostructures resulted in excellent broadband absorption in the UV-Vis-NIR region (300-1100 nm), and hence a black color, without an additional post-treatment process. When used as photothermal conversion materials, the hybrid nanostructures showed good photothermal conversion activity, with a maximum efficiency of 76.1% under irradiation with an 808 nm near-infrared laser. A mechanism for the high photothermal conversion activity is proposed on the basis of experimental and simulation results. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A novel method for synthesizing metal-semiconductor@ bimetal hybrid nanostructures with unique porous architectures has been described. These structures exhibit excellent broadband absorption in the UV-Vis-NIR region and high photothermal conversion efficiency. Mechanism for the high photothermal conversion activity was proposed based on experimental and simulation results.