Smart and Reversible Surface Plasmon Resonance Responses to Various Atmospheres for Silver Nanoparticles Loaded in Mesoporous SiO₂

Abstract

The surface plasmon resonance (SPR) optical absorption of Ag nanoparticles loaded in mesoporous SiO2 (with fairly low Ag content, about 0.14 wt %) have been investigated after the nanoparticles were heated in or exposed to various atmospheres (i.e., air, H2, water vapor, Ar, and H2S). Unexpectedly, the SPR optical absorption can completely disappear in quite a short time or intensively emerge or drastically change into semiconductor optical absorption edge. Surprisingly, the SPR switches are well reversible and very rapid when alternating treatment of samples in any two atmospheres mentioned above. In addition, those novel and distinctive SPR changes reflect a series of abnormal chemical redox behaviors in various atmospheres. The mechanisms have been discussed based on modeling multi-interactions between the mesoporous SiO2 matrix, Ag nanoparticles, and atmospheres, revealing a special surface/interface synergetic effect that induces many novel phenomena despite SiO2 usually being regarded as a chemical inert medium to noble metals and environmental atmospheres. Our new findings for such a simple Ag/SiO2 system, smart, reversible, and rapid SPR responses to various atmospheres, are highly valuable for SPR gas sensor, optical switch, and other SPR optics and give a new understanding of the catalysis and surface/interface chemistry in the Ag/SiO2 system.

Monitoring Solvent Evaporation from Thin Films by Localized Surface Plasmon Resonance Shifts

“…For example, Hu et al studied the changes in the LSPR of Ag nanoparticles included in a mesoporous SiO 2 thin film due to the exposure to different atmospheres. 17 Also, Bois et al studied the color changes produced due to oxidation in Ag particles * To whom correspondence should be addressed. E-mail: angelome@ uvigo.es.…”

Petahertz-frequency plasmons in graphene nanopore and their application to nanoparticle sensing

“…Recently, graphene has been utilized as pressure sensor [8], dipolar-antenna in the terahertz frequency range [9], and membrane for DNA translocation detection [10]. Surface Plasmon Resonances (SPR) and plasmon propagation in graphene have attracted attention due to their great application in nano-photonics, biology, sensing, gap detection, and DNA sensing [8,[11][12][13]. Di erent types of the plasmon in graphene are: (1) collective-intraband excitation of the conductance electrons with 0-3 eV energy, (2) collective-interband excitations of the valance electrons with 4-12 eV energy, and (3) collective-interband excitations of all valence electrons ( + plasmon) with 14-33 eV energy [14][15][16][17][18][19][20][21].…”

Photocatalytic activity in monodisperse In2O3 nanocrystals incorporated into transparent silica glassy matrix

“…The structure arrangement of nanocrystal-in-glass, for example, not only combines two functional components in one material, but also the covalent link enables us to manipulate the glass structure to change its properties. To the best of our knowledge, some reports have described that incorporating nanocrystalline precipitates within glassy matrices can effectively improve their properties [10][11][12][13][14][15][16][17][18]. Thus selecting a suitable nanocrystal-in-glass system and developing an effective synthetic process for incorporating NCs into glassy matrix becomes very important in the field of materials science.…”