Revealing the Synthesis of Triangular Silver Nanoplates: A Study of the Photochemical Growth Mechanism around the pH and Trisodium Citrate Variations

Abstract

Triangular silver nanoplates (T‐SNPs) are synthesized via a facile, low‐cost photochemical process. It is proved that both the pH and the concentration of trisodium citrate (TSC) are the key factors to describe the mechanism for the photochemical growth and modulation of the extinction band along the formation of T‐SNPs. A precise photoreduction growth mechanism of T‐SNPs is proposed and confirmed by X‐ray photoelectron spectroscopy (XPS) considering the face block theory and the localized surface plasmon resonance (LSPR) in T‐SNPs revealing the optimal conditions for their growth to be at a neutral pH of 7, a concentration between 1.0 and 2.0 mm of TSC preferentially monodentate, and using a 520 nm excitation energy. These results exhibit important implications for the behavior of T‐SNPs in a wide variety of plasmonic applications that can be further moved to controlled surface‐enhanced biomedical applications.

Photochemical Optimization of a Silver Nanoprism/Graphene Oxide Nanocomposite’s Antibacterial Properties

“…This peak is attributed to the out-of-plane quadrupole resonance mode in anisotropic flat S-NPs. ,, This peak is essential to confirm the presence of flat structures in the nanocomposite material. The second band wavelength-dependent between 500 and 1000 nm is assigned to the dipolar in-plane or longitudinal surface plasmon resonance (SPR) in anisotropic flat nanostructures. , This second band is considered the fingerprint of anisotropic flat S-SNPs, and its resonance frequency depends on the excitation energy used during the photoreduction process . We observed the position of this band to redshift as a function of λ irr of irradiation corresponding to the following values listed in Table .…”

“…The proposed mechanism that describes the photochemical growth for anisotropic flat Ag-NPs is based on the face block theory, and the Localized Surface Plasmon Resonance (LSPR) as described elsewhere. 22 The photochemical reduction mechanism allows nanoparticle size and shapes tunability on the GO surface by changing the irradiation wavelength (blue, green, red, and white). Figure 1 shows a schematic description of the photoconversion process starting from seeds AgNPs (Nucleation) toward anisotropic flat S-NPs , deposited on GO.…”

“… 29 , 31 This second band is considered the fingerprint of anisotropic flat S-SNPs, and its resonance frequency depends on the excitation energy used during the photoreduction process. 22 We observed the position of this band to redshift as a function of λ irr of irradiation corresponding to the following values listed in Table 1 . The large width of these strong bands reveals a large size distribution of nanoparticles in the colloidal suspension.…”

“…The analysis spot had a diameter of 50 μm and 45° detection angle relative to the substrate surface with a resolution of 0.5 eV. The atomic concentration for each element was calculated using Mutipak Version 9.8.0.19 (Ulvac-phi, Inc.); this software used the peak intensity (peak area) in units of counts per second considering the specific relativity sensitivity factor for each element. − Background subtraction was unnecessary due to the high-intensity peaks and nonimportant energy losses before emission from the sample.…”

Photochemical growth of silver nanoplates on graphene oxide for the electrochemical sensing of hydrogen peroxide

“…When the sample was exposed to light irradiation at 540 nm excitation wavelength, the excess of ions generated around the silver nanoparticles was reduced. At the same time, trisodium citrate allowed the formation of other shapes of Ag nanostructures, such as nanoplates and planar structures [14]. In Figures 3 (f), the formation of large planar nanoparticles on GO after the photoreduction process is confirmed.…”