Capping effect of reducing agents and surfactants in synthesizing silver nanoplates

The effect of reducing agents and surfactants on controlling the silver nanoplates was studied. Two reducing agents, trisodium citrate dehydrate (TSC) and potassium tartrate, were used to reduce the AgNO3 solution. In this redox system, polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS) and arabic gum were served as surfactants. The results showed that reducing agents and surfactants both act as the capping agent adhering to the certain facets of silver seeds to block this surface to grow. The relative intensity of reducing agents also takes an active part in influencing the growth rate and direction of silver seeds. It was also found that halides can accelerate the speed of Ostwald ripening by adding Cl?, Br? and I?into the aqueous and have some effects on the morphology of the nanoplates.

Convenient synthesis of silver nanoplates with adjustable size through seed mediated growth approach

Silver nanoplates,with average thickness about 5 nm and average tunable size from 40 to 500 nm,were synthesized via a simple room-temperature solution-phase chemical reduction method in the presence of appropriate concentration of trisodium citrate and silver seeds.The optical in-plane dipole plasmon resonance bands of these silver plates could be tuned from 520 to 1100 nm.Control experiments were explored for understanding of the growth mechanism.It is found that both the amount of citrate ions and the small silver seeds added to the growth solution are the key to controlling the silver nanoplates without changing their thickness and crystal structure.Small silver seeds are found to play an important role in the formation of large thin silver nanoplates when poly（vinylpyrrolidone）（PVP） are used as capping agent.

The Evolution of the Extinction and Growth Mechanism of the Silver Nanoplates

The time-dependence evolution of the extinction spectra of the silver nanoplates is studied to analyze the underlying physical mechanism of the growth process. As the synthesis cycles increase, the wavelength of the absorption peak is first blue-shifted and then is followed by the red shift, attributing to the mode alteration of the longitudinal surface plasmon resonance of the silver nanoplates. The capping agents are also optimized for the convenient and speedy growth of the large integrated Ag nanostructure. These observations expand the comprehensive understanding of plasmon resonance of the Ag nanoplates, and give a better manipulation of their applications in the plasmonie nanodevices.

Modulating absorption band of triangular silver nanoplates in aqueous solvent and on substrates using tannin as reducing agent

Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and the small triangular silver nanoplate seeds added to the growth solution are the key factors to modulation absorption band of triangular silver nanoplates.The optical in-plane dipole surface plasmon resonance (SPR) bands of these Ag nanoplates can be tuned from 608 nm to 980 nm via tannin deoxidization method.The formation mechanism of triangular silver nanoplates was proposed.The tannin deoxidization method realizes a convenient modulation of the absorption band of Ag nanostructures within the visible near-infrared (IR) region both in aqueous solvent and on substrates under mild conditions.

Controlled synthesis of silver nanoplates and nanoparticles by reducing silver nitrate with hydroxylamine hydrochloride

An easy and effective method of silver nanoplate synthesis technique was created by reducing silver nitrate （AgNO3） with hydroxylamine hydrochloride （NH2OH·HCl） at room temperature. Silver nanoplates of various shapes, including triangular, truncated triangular, hexagonal, and truncated hexagonal, exhibit an average width and thickness of approximately 1 μm and 50 nm, respectively. Silver nanoparticles were acquired by placing polyvinyl pyrrolidone （PVP） in the reaction solution. The produced silver nanoparticles are quasi-spherical in shape and - 100 nm in size. The catalytic activity in the thermal decomposition of ammonium perchlorate （AID） was distinguished by thermogravimetric （TG） analysis and differential scanning calorimetry （DSC）. The outcomes reveal that the addition of silver nanoplates and nanoparticles diminishes the low decomposition temperature of AP by 7 and 14 ℃ and leads to a drop in the high decomposition temperature of AP by 60 and 110 ℃ and a rise in the total DSC heat release by 0.86 and 1.05 kJ.g^-1, respectively.

Optical Properties of Silver Nanoplates Synthesized by Photoinduced Method

Silver nanoplates were synthesized in aqueous solution by photoinduced chemical reduction method with tungsten lamp as light source.The growth process was analyzed and characterized.The linear absorption spectra showed that,along with the growth process,the surface plasmon resonance of silver seed nanoparticles at 395 nm decreased gradually,while a new plasmon band at 740 nm corresponding to silver nanoplates appeared and increased gradually.Z-scan technique was used to explore the nonlinear optical properties of silver nanoplates.The results displayed that with the reaction time increases from 0 h to 24 h,the value of nonlinear absorption（NLA） coefficient and the value of nonlinear refraction（NLR） index of the products increased from 0 to 3.167 cm/GW and from 0.64×10^ 4 to 6.83×10 ^4 cm 2 /GW,respectively.

Tuning plasmon absorption of unmodified silver nanoplates for sensitive and selective detection of copper ions by introduction of ascorbate

Silver nanoplates as novel optical sensors for Cu^2＋ detection have been demonstrated.Silver nanoplates are synthesized via previous H_2O_2-NaBH_4 cyclic oxidation-reduction reactions.With introduction of ascorbate as mild reductants,Cu^2＋ ions are reduced into Cu~＋ and the Cu^＋ is further reduced to Cu,which is deposited on the surface of the silver nanoplates.The deposition of the Cu on the surface of the silver nanoplates allows a significant red-shift of their plasmon absorption.Therefore,trace Cu^2＋ can be detected.The shift of the plasmon absorption wavelength of silver nanoplates is proportional to the Cu^2＋concentration over a range of 40-340 μmol L^（-1） with a limit of detection of 9.0 μmol L^（-1）.Moreover,such silver nanoplate-based optical sensors provide good selectivity for Cu^2＋ detection,and most other metal ions do not disturb its detection.Moreover,the practicality of the proposed sensor was tested.This Cu^2＋assay is advantageous in its simplicity,selectivity,and cost-effectiveness.

Passively Q-Switched Yb-Doped Fiber Laser Operating at 1.06 μm with Two-Dimensional Silver Nanoplate as Saturable Absorber

A two-dimensional silver nanoplate is prepared with the seed-mediated growth method and is used for achieving pulse fiber laser operation. By controlling the dimension parameters of the silver nanoplate, the surface plasmon resonance absorption peak of the material is successfully adjusted to 1068 nm. Based on the silver nanoplate as a saturable absorber, a passively Q-switched Yb-doped fiber laser operating at 1062 nm is demonstrated. The maximum average output power of 3.49mW is obtained with a minimum pulse width of 1.84#s at a pulse repetition rate of 65.TkHz, and the corresponding pulse energy and peak power are 53.1 nJ and 28.8mW, respectively.

A Rapid Visual Detection of Ascorbic Acid Through Morphology Transformation of Silver Triangular Nanoplates

A rapid and sensitive colorimetric detection of ascorbic acid(AA)through the morphology transformation of silver triangular nanoplates(Ag TNPs)is developed.By virtue of the redox reaction among silver nitrate and A A,the newly formed Ag atoms deposited on the surfaces of Ag TNPs.Subsequently,the morphology of Ag TNPs transforms from triangle to circle,resulting in a more than 160 nm blue shift of localized surface plasmon resonance absorption peak.The corresponding color of the solution converting from blue to yellow with the concentration of AA can be observed by naked eyes within 15 min.A linear relationship between the blue shift of absorption peak and the concentration of A A ranging from 0.2 to 6μM is obtained with a limit of detection(LOD)of 100 nM(3σ).Some potential species(e.g.,glucose,urea and various amino acids)coexisting in the system showed little or no interference.The proposed assay is successfully employed to determine the amount of A A in pharmaceutical products with recoveries from 96.9 to 106.5%and offers a sensitive,low-cost,rapid and simple assay of visual analysis of ascorbic acid.

1D-2D nanohybrid-based textile strain sensor to boost multiscale deformative motion sensing performance

The development of strain sensors with both superior sensitivity(gauge factor(GF)>100)and broad strain-sensing range(>50%strain)is still a grand challenge.Materials,which demonstrate significant structural deformation under microscale motion,are required to offer high sensitivity.Structural connection of materials upon large-scale motion is demanded to widen strainsensing range.However,it is hard to achieve both features simultaneously.Herein,we design a crepe roll structure-inspired textile yarn-based strain sensor with one-dimensional(1D)-two-dimensional(2D)nanohybrid strain-sensing sheath,which possesses superior stretchability.This ultrastretchable strain sensor exhibits a wide and stable strain-sensing range from microscale to large-scale(0.01%–125%),and superior sensitivity(GF of 139.6 and 198.8 at 0.01%and 125%,respectively)simultaneously.The strain sensor is structurally constructed by a superelastic 1D-structured core elastomer polyurethane yarn(PUY),a novel high conductive crepe roll-structured(CRS)1D-2D nanohybrid multilayer sheath which assembled by 1D nanomaterials silver nanowires(AgNWs)working as bridges to connect adjacent layers and 2D nanomaterials graphene nanoplates(GNPs)offering brittle lamellar structure,and a thin polydopamine(PDA)wrapping layer providing protection in exterior environment.During the stretching/deformation process,microcracks originate and propagate in the GNPs lamellar structure enable resistance to change significantly,while AgNWs bridge adjacent GNPs to accommodate applied stress partially and boost strain.The 1D crepe roll structure-inspired strain sensor demonstrates multifunctionality in multiscale deformative motion detection,such as respiratory motions of Sprague–Dawleyw rat,flexible digital display,and proprioception of multi-joint finger bending and antagonistic flexion/extension motions of its flexible continuum body.