The Effects of Native Oxides on the Selective Photo-Reduction Property of Cu Nanoparticles Induced by the Localized Surface Plasmon

• Published in: Plasmonics (Norwell, Mass.) Vol. 18; no. 1; pp. 73 - 82
• Main Authors: Fang, Yingcui, Li, Lei, Li, Huanhuan, Zhao, Shiqi, Cheng, Zhitao, Nian, Yujie, Xu, Bin, Chu, Xiangqian, Sun, Mengtao
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2023; Springer Nature B.V
• Subjects: Biochemistry; Biological and Medical Physics; Biophysics; Biotechnology; Chemistry; Chemistry and Materials Science; Copper; Copper oxides; Core-shell structure; Evolution; Monitoring; Nanoparticles; Nanotechnology; Photoelectrons; Raman spectra; Reduction; Silver; Native oxides; Localized surface plasmon resonance; Selective photocatalysis; Copper nanoparticles
• ISSN: 1557-1955; 1557-1963
• DOI: 10.1007/s11468-022-01689-6

Copper nanoparticles (CuNPs) in air are easily oxidized into CuNPs@Cu 2 O core–shell structure. The localized surface plasmon resonance (LSPR) of CuNPs can be damped seriously by the Cu 2 O shell. The effect of this native Cu 2 O layer on the LSPR-induced selective photocatalysis properties of CuNPs is often ignored. In this paper, this effect was explored by comparison of the evolution of the photo-reduction efficiency (PRE) with the nanoparticle size ( d ) of the as-deposited CuNPs to that of AgNPs via monitoring the transformation from 4-nitrothiophenol (PNTP) to 4,4 trdimercaptoazobenzene (DMAB) using surface enhanced Raman scattering. It was found that the PRE of the as-deposited CuNPs increases first and then decreases with increasing d , much different from that of AgNPs: increases with increasing d . Based on the transmission electron microscope images, X-ray photoelectron spectroscopy, and by monitoring the PRE stability in air of the as-deposited CuNPs, the mechanisms of the PRE evolution with d and the laser illumination time ( t ) were suggested. Cu 2 O plays a dominated role when the nanoparticles’ sizes were small. Both Cu 2 O and CuNPs play roles when the nanoparticles’ sizes were large, which brought in the low PRE of the as-deposited CuNPs.