Poly(vinylpyrrolidone)‐Free Multistep Synthesis of Silver Nanoplates with Plasmon Resonance in the Near Infrared Range

Abstract

Herein, a poly(vinylpyrrolidone) (PVP)-free method is described for synthesizing Ag nanoplates that have localized surface plasmon resonance in the near-infrared (NIR) range. Citrate-capped Ag spherical nanoparticles are first grown into small Ag nanoplates that resonate in the range of 500-800 nm. The small Ag nanoplates are used as seeds to further grow into large Ag nanoplates with a lateral dimension of 100-600 nm and a plasmon resonance wavelength of 800-1660 nm and above. The number of growth steps can be increased as desired. Without introducing additional citrate into the solutions of small Ag nanoplate seeds, large Ag nanoplates can be synthesized within minutes. The entire synthesis is completely PVP free, which promotes the nanoparticle growth along the lateral direction to form large Ag nanoplates. The multistep growth and the minimum usage of citrate are essential for the fast growth of high-aspect-ratio Ag nanoplates resonating in the NIR range.

Green synthesis of silver nanoplates using the special category of plant leaves showing the lotus effect

“…The characterization results in the present work are also in agreement with the journals reporting the synthesis of silver nanoplates using chemical methods. [27][28][29][30][31][32] All the three types of plant leaves were super hydrophobic as the reported contact angles for each of the three types of leaf surface was near 160 . 33,34 A certain ratio of some phytochemicals like gallic acid and quercetin present in plant leaves may be responsible for reduction and then stabilization of the nanostructures.…”

Wet-chemical synthesis of two-dimensional metal nanomaterials for electrocatalysis

“…For instance, Khan et al. demonstrated the synthesis of large triangular Ag nanoplates from small Ag spherical seeds, and investigated the effect of poly(sodium 4-styrene-sulfonate) (PSSS) on regulating the shape of Ag [ 84 ]. The usage of PSSS generated the defective structures in Ag spherical seeds, which led to the anisotropic growth of Ag on the Ag seeds to form a 2D structure.…”

Non-toxic near-infrared light-emitting diodes

“… Shape Materials Size Resonance peak [nm] a Resonance window [nm] Ref. Diameter/Length [nm] Width [nm] Shell [nm] Sphere CS-AuNR-ICG nanosphere 180 720, 805 650–900 ( Chen et al., 2013 ) Dpa-Melanin nanospheres 70 700 300–1000 ( Liu et al., 2013 ) Rod Au nanorods 50 13 788 650–950 ( Zheng et al., 2014 ) Au nanorods 72 16 835 700–1100 ( Pan et al., 2019 ) Ag nanorods 142 49.5 790 650–900 ( Pietrobon et al., 2009 ) Plate Ag nanoplates 77 700 400–900 ( Khan et al., 2017 ) Mg nanoplates 162 700 200–1000 ( Biggins et al., 2018 ) Cube Ag nanocubes 80 80 810 450–1200 ( Kawawaki et al., 2015 ) Pore Na...…”