Maintaining the localized surface plasmon resonance of copper nanoparticles by defective TiO2 thin films

Abstract

The localized surface plasmon resonance (LSPR) of copper nanoparticles (CuNPs) damps quickly in air due to the easy oxidation of copper atoms. Finding ways to retard the oxidation of CuNPs is critical for the applications based on the LSPR of CuNPs. In this paper, we report on a new method to maintaining the LSPR of CuNPs by deposition of CuNPs on TiO 2 thin films in vacuum followed by annealing in nitrogen ambient. The anti-oxidation properties of the CuNPs were improved greatly. In three days, the LSPR intensities at 532 and 633 nm were reduced by only 40 and 32%, respectively. This method is simple and cost-effective.

Recent Advancements of LSPR Fiber-Optic Biosensing: Combination Methods, Structure, and Prospects

“…LSPR is an optical property of noble metal nanoparticles, but AgNPs [ 31 ] and CuNPs [ 32 ] are easily oxidized by air. AuNPs have been widely used in experiments due to their good structural stability, so in this review, the binding method of gold nanoparticles and optical fibers is mainly explained.…”

Highly stable localized surface plasmon resonance of Cu nanoparticles obtained via oxygen plasma irradiation

“…Recently, new techniques have been continuously developed. In 2021, our group first reported a technique using defective TiO 2 thin films as electrons donors to prevent the oxidation of CuNPs, 16 but the protection diminished after 72 hours due to electron depletion. In 2022, Chung et al reported a more effective method for electron supply by growing CuNPs on the surface of a [Gd 2 C] 2+ •2e − electrode; 17 good stability was obtained.…”

“…Recently, new techniques have been continuously developed. In 2021, our group first reported a technique using defective TiO 2 thin films as electrons donors to prevent the oxidation of CuNPs, 16 but the protection diminished after 72 hours due to electron depletion. In 2022, Chung et al .…”