Biosynthesis of Silver Nanoparticles and Their Applications in Harvesting Sunlight for Solar Thermal Generation

Abstract

Silver (Ag) nanoparticles (NPs) have been synthesized through an easy, inexpensive, and ecofriendly method. Petroselinum crispum, parsley, leaf extract was utilized as a reducing, capping, and stabilizing agent, without using any hazardous chemical materials, for producing Ag NPs. The biosynthesized Ag NPs were characterized using different characterization techniques, namely UV-Vis, FT-IR spectroscopy, X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), dynamic light scattering (DLS), zeta potential, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), transmission electron microscope (TEM), field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray (EDX) analysis to investigate the optical, thermal, structural, morphological, and chemical properties of the plant extract and the biosynthesized Ag NPs. After that, the biosynthesized Ag NPs were utilized in harvesting sunlight for solar thermal generation. Surface plasmon resonance (SPR) for the green synthesized Ag NPs with the dark color were adjusted at nearly 450 nm. Once the Ag NPs are excited at the SPR, a large amount of heat is released, which causes a change in the local refractive index surrounding the Ag NPs. The released heat from the Ag NPs under the solar irradiation at the precise wavelength of plasmon resonance significantly increased the temperature of the aqueous medium. Different percentages of Ag NPs were dispersed in water and then exposed to the sunlight to monitor the temperature of the suspension. It was found that the temperature of the aqueous medium reached its highest point when 0.3 wt. % of Ag NPs was utilized. This investigation is rare and unique, and it shows that utilizing a small amount of the biosynthesized Ag NPs can increase the temperature of the aqueous medium remarkably.

Green Synthesis and Characterization of Silver Nanoparticles with High Antibacterial Activity Using Cell Extracts of Cyanobacterium Pseudanabaena/Limnothrix sp.

“…Moreover, under slightly basic conditions (pH 8), the SRP p redshifted to 540 nm, hence implying the formation of AgNPs that are larger in [16,26]. However, our results are inconsistent with a previous study that repo The absorption bands at 400-450 nm confirmed the formation of AgNPs [14,24]. Furthermore, the spectra also revealed that the formation of AgNPs were favorable under slightly acidic (pH 5-6) and neutral (pH 7) conditions.…”

Polyphenol-Capped Biogenic Synthesis of Noble Metallic Silver Nanoparticles for Antifungal Activity against Candida auris

“…The existing water-soluble polyphenolic molecules in Cynara cardunculus extract successfully reduced the available silver metal ion (Ag + ) to metallic silver nanoparticles (Ag 0 ) [ 53 ]. The bioreduction of metal ions to metallic nanoparticles takes place through an activation step, which involves the reduction of available silver metal ions followed by the nucleation and growth steps in which metal nanoparticles of definite shapes and sizes are formed [ 54 ]. Finally, the stabilization step takes place, in which the Cynara cardunculus extract metabolites similarly play the role of surface-capping agents to prevent the nanoparticles from agglomerating [ 54 ].…”

“…The bioreduction of metal ions to metallic nanoparticles takes place through an activation step, which involves the reduction of available silver metal ions followed by the nucleation and growth steps in which metal nanoparticles of definite shapes and sizes are formed [ 54 ]. Finally, the stabilization step takes place, in which the Cynara cardunculus extract metabolites similarly play the role of surface-capping agents to prevent the nanoparticles from agglomerating [ 54 ]. The proposed mechanism of CC-AgNPs formation via Cynara cardunculus extract is depicted in systematic Figure 1 .…”

Green synthesis of SiO2 nanoparticles from Rhus coriaria L. extract: Comparison with chemically synthesized SiO2 nanoparticles

“…The novelty of this study is that it used green synthesis to manufacture SiO 2 NPs from their first product (Na 2 SiO 3 ), completing their approach entirely using green synthesis. This investigation is our ongoing study in the green synthesis NPs area [24][25][26][27][28][29][30][31][32][33][34][35].…”