Gold nanoparticles (AuNPs) are used
in various biological applications
because of their small surface area-to-volume ratios, ease of synthesis
and modification, low toxicity, and unique optical properties. These
properties can vary significantly with changes in AuNP size, shape,
composition, and arrangement. Thus, the stabilization of AuNPs is
crucial to preserve the properties required for biological applications.
In recent years, various polymer-based physical and chemical methods
have been extensively used for AuNP stabilization. However, a new
stabilization approach using biomolecules has recently attracted considerable
attention. Biomolecules such as DNA, RNA, peptides, and proteins are
representative of the biomoieties that can functionalize AuNPs. According
to several studies, biomolecules can stabilize AuNPs in biological
media; in addition, AuNP-conjugated biomolecules can retain certain
biological functions. Furthermore, the presence of biomolecules on
AuNPs significantly enhances their biocompatibility. This review provides
a representative overview of AuNP functionalization using various
biomolecules. The strategies and mechanisms of AuNP functionalization
using biomolecules are comprehensively discussed in the context of
various biological fields.
The performance of aluminum-air battery is improved by adding agar molecules to the electrolyte (4 M NaOH). A significant suppression of the parasitic self-corrosion reaction and the improvement of fuel efficiency were obtained. The fuel efficiency is elevated up to 35.95% and the corrosion inhibition efficiency increases up to 62.8%. The physisorption of the agar molecules on the aluminum surface improved the performance of aluminum-air battery. The adsorption of agar molecules on the aluminum surface was observed from the surface analysis with SEM, Freundlich adsorption isotherm and the adsorption energies from the computational simulations. Furthermore, the optimized structure model of agar molecules on the aluminum surface was proposed. To figure out the inhibition performance of agar molecules as an electrolyte additive for aluminum-air batteries, the experimental methods such as hydrogen evolution test, electrochemical tests, surface analysis and density functional theory (DFT) with computational simulations are used in this study.
The
low sheet resistance and high optical transparency of silver nanowires
(AgNWs) make them a promising candidate for use as the flexible transparent
electrode of light-emitting diodes (LEDs). In a perovskite LED (PeLED),
however, the AgNW electrode can react with the overlying perovskite
material by redox reactions, which limit the electroluminescence efficiency
of the PeLED by causing the degradation of and generating defect states
in the perovskite material. In this study, we prepared Ag–Ni
core–shell NW electrodes using the solution-electroplating
technique to realize highly efficient PeLEDs based on colloidal formamidinium
lead bromide (FAPbBr3) nanoparticles (NPs). Solvated Ni
ions from the NiSO4 source were deposited onto the surface
of AgNW networks in three steps: (i) cathodic cleaning, (ii) adsorption
of the Ni-ion complex onto the AgNW surface, and (iii) uniform electrodeposition
of Ni. An ultrathin (∼3.5 nm) Ni layer was uniformly deposited
onto the AgNW surface, which exhibited a sheet resistance of 16.7
Ω/sq and an optical transmittance of 90.2%. The Ag–Ni
core–shell NWs not only increased the work function of the
AgNW electrode, which facilitated hole injection into the emitting
layer, but also suppressed the redox reaction between Ag and FAPbBr3 NPs, which prevented the degradation of the emitting layer
and the generation of defect states in it. The resulting PeLEDs based
on FAPbBr3 NPs with the Ag–Ni core–shell
NWs showed high current efficiency of 44.01 cd/A, power efficiency
of 35.45 lm/W, and external quantum efficiency of 9.67%.
Arsenic oxide (As(Ⅲ)), sodium phosphate monobasic anhydrous (H2PO4-), and antimony trioxide (Sb(Ⅲ)) are used as electrolyte additives in 4M sodium hydroxide (NaOH) electrolyte for Al-air batteries. The effects of inorganic additives are examined through hydrogen evolution and selfcorrosion testing, electrochemical analysis, and surface analysis. Electrochemical tests show that the presence of the additives lowers the hydrogen gas evolution rate and inhibits the adsorption of hydrogen on the aluminum surface. The additives in order of effectiveness are: Sb(Ⅲ) > As(Ⅲ) > H2PO4-. The addition of additives decreases the self-corrosion of 4N Al, which improves the efficiency of the Al-air battery. The additives are confirmed as effective inhibitors of the hydrogen generation reaction in Al-air batteries.
In this study, we performed metal (Ag, Ni, Cu, or Pd) electroplating of core–shell metallic Ag nanowire (AgNW) networks intended for use as the anode electrode in organic light-emitting diodes (OLEDs) to modify the work function (WF) and conductivity of the AgNW networks. This low-cost and facile electroplating method enabled the precise deposition of metal onto the AgNW surface and at the nanowire (NW) junctions. AgNWs coated onto a transparent glass substrate were immersed in four different metal electroplating baths: those containing AgNO3 for Ag electroplating, NiSO4 for Ni electroplating, Cu2P2O7 for Cu electroplating, and PdCl2 for Pd electroplating. The solvated metal ions (Ag+, Ni2+, Cu2+, and Pd2+) in the respective electroplating baths were reduced to the corresponding metals on the AgNW surface in the galvanostatic mode under a constant electric current achieved by linear sweep voltammetry via an external circuit between the AgNW networks (cathode) and a Pt mesh (anode). The amount of electroplated metal was systematically controlled by varying the electroplating time. Scanning electron microscopy images showed that the four different metals (shells) were successfully electroplated on the AgNWs (core), and the nanosize-controlled electroplating process produced metal NWs with varying diameters, conductivities, optical transmittances, and WFs. The metal-electroplated AgNWs were successfully employed as the anode electrodes of the OLEDs. This facile and low-cost method of metal electroplating of AgNWs to increase their WFs and conductivities is a promising development for the fabrication of next-generation OLEDs.
Aluminum-air battery is a chemical cell that provides high theoretical energy density. However, the anodic dissolution rate of aluminum in 4 M NaOH solution is limited by the film formed on aluminum surface. Electrochemical measurements and scanning electron microscope (SEM) images after potentiostatic polarization were used to analyze the surface structure, ionic reactions, and anodic dissolution of aluminum in 4 M NaOH with chloride solution. The anodic dissolution is mainly affected by aluminum oxide layer. Chloride suppresses slightly the anodic dissolution below the breakdown potential. However, above the breakdown potential, chloride breaks down the oxide layer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.