Porous Hybrids Structure between Silver Nanoparticle and Layered Double Hydroxide for Surface-Enhanced Raman Spectroscopy

Abstract

Silver nanoparticle (AgNP), in terms of antibacterial, catalytic, electronic, and optical applications, is an attractive material. Especially, when prepared to furnish sharp edge and systematic particle orientation on the substrate, AgNPs can take advantage of surface-enhanced Raman spectroscopy (SERS). In this research, we suggested a synthetic method to immobilize the AgNP on metal oxide by utilizing Ag-thiolate and layered double hydroxide (LDH) as precursor and template, respectively. The layer-by-layer structure of LDH and Ag-thiolate transformed through reductive calcination to metal oxide and AgNP array. Physicochemical characterization, including powder X-ray diffraction, N2 adsorption–desorption, microscopies, and X-ray photoelectron spectroscopy, revealed that the AgNP with sufficient crystallinity and particle gap was obtained at relatively high calcination temperature, ~600 °C. UV-vis diffusion reflectance spectroscopy showed that the calcination temperature affected particle size and electronic structure of AgNP. The prepared materials were subjected to SERS tests toward 4-nitrothiophenol (4-NTP). The sample obtained at 600 °C exhibited 50 times higher substrate enhancement factor (SEF) than the one obtained at 400 °C, suggesting that the calcination temperature was a determining parameter to enhance SERS activity in current synthetic condition.

Synthesis and Antioxidant Activity of Silver Nanoparticles Using the Odontonema strictum Leaf Extract

“…According to Francesco Porcaro and coworkers, the Ag3d 5/2 component at about 367 eV corresponds to unperturbed metallic silver, as expected for atoms in the NP core [ 34 ]. In fact, the Ag 3d 5/2 electrons in zero-valency Ag, monovalent Ag 2 O, and divalent AgO were reported to have binding energies in the ranges of 367.9–368.3, 367.7–368.4, and 367.3–368.1 eV, respectively, by XPS analysis ( Figure 4 C) [ 35 ].…”

Biosynthesis and Characterization of Silver Nanoparticles from the Extremophile Plant Aeonium haworthii and Their Antioxidant, Antimicrobial and Anti-Diabetic Capacities

“…G. Don leaf extract mentioned identical spherical shape nanoparticles with a diameter of 35–55 nm [ 52 ]. The inter-particles distance is an important factor in hotspot evolution and signal enhancement [ 53 ].…”

Phytosynthesis via wasted onion peel extract of samarium oxide/silver core/shell nanoparticles for excellent inhibition of microbes

“…4 shows the XPS survey spectra of Ag@Sm 2 O 3 -onion. It reveals four peeks at bending energies at 373.90 eV, 367.90 eV, 1081 eV and 1110 eV which are attributed to Ag 3d 5/2 ,Ag 3d 3/2 , Sm 3+ 3d 5/2 and Sm 3+ 3d 3/2 , respectively [ 35 ]. The Sm 2 O 3 and Ag@Sm 2 O 3 spectra both showed the O 1s with binding energies of ∼528 eV and 531 eV.…”