Hydriodic Acid Research Articles

The efficacy of iodinated ethyl esters of safflower seed oil (Carthamus tinctorius L.) in the control of iodine deficiency in sheep

Iodine is an essential component of the thyroid gland hormones (T3 and T4), necessary for mammalian life. Iodine deficiency leads to inadequate thyroid hormone production, and all the consequences of iodine deficiency stem from the associated hypothyroidism. Iodized oil is made by treating a fatty vegetable oil with iodine or hydriodic acid and is an effective long-term means of iodine supplementation. The type and fatty acids profile in the parent oil, as well as the way iodine is trapped, affect the physicochemical properties and effectiveness of the product. This research was conducted to study the effect of iodinated safflower oil on preventing iodine deficiency disorders (IDD) in livestock, compared with a commercial iodine supplement. Iodinated fatty acid ethyl esters prepared from safflower seed oil (IFAEESSO). Thirty Farahani ewes with a history of iodine deficiency were divided into three groups, including control and two treatment groups. The treatment groups received 390 mg of iodine by an intramuscular injection of 1.26 ml of IFAEESSO (n = 10) or 1.5 ml of Depodine® (n = 10), respectively. Serum iodine, thyrotropin stimulating hormone (TSH), T3 and T4 concentrations were assayed at baseline and every 30-day intervals over six months period. Iodine supplementation resulted in a significant increase in serum inorganic iodine over five months with Depodine and IFAEESSO (P < 0.01). Serum T3 and T4 concentrations also increased in treatment groups (P < 0.01), while the concentration of TSH didn’t change. The mean T4 and T3 concentrations were 3.16 μg /dl and 53.89 ng /dl in the control group, which increased to 3.50 μg /dl and 58.88 ng/dl for Depodine and 3.88 μg /dl and 63.55 ng/dl for IFAEESSO, respectively. The serum inorganic iodine and thyroid hormone concentrations were significantly higher in the IFAEESSO group than in the Depodine group (P < 0.01). IFAEESSO is an effective supplement against IDD and more efficient than that of Depodine to increase serum iodine concentration, and thyroid hormone production.

In Situ Iodide Passivation Toward Efficient CsPbI3 Perovskite Quantum Dot Solar Cells

HighlightsThe introduction of hydroiodic acid (HI) manipulates the dynamic conversion of PbI2 into highly coordinated species to optimize the nucleation and growth kinetics.The addition of HI enables the fabrication of CsPbI3 perovskite quantum dots with reduced defect density, enhanced crystallinity, higher phase purity, and near-unity photoluminescence quantum yield.The efficiency of CsPbI3 perovskite quantum dot solar cells was enhanced from 14.07% to 15.72% together with enhanced storage stability.All-inorganic CsPbI3 quantum dots (QDs) have demonstrated promising potential in photovoltaic (PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid (HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI2 into highly coordinated [PbIm]2−m, enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on further understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.

Proton-Mediated Structural and Optical Recovery of a UV-Degraded Colloidal Ruddlesden–Popper Perovskite Nanoplate for Prolonged Application

Two-dimensional Ruddlesden–Popper (RP) lead halide perovskite nanoplates (NPls) have recently attracted attention due to their superior properties in optoelectronics. However, structural degradation of these materials under continuous photoexcitation restricts their acceptability. Herein, we report an instantaneous structural as well as optical recovery of colloidal (OAm)2(CH3NH3PbI3)2PbI4 RP NPls from its UV-degraded stage through a simple “protonation” approach by proton-donating species like 1-dodecanethiol, 4-aminothiophenol, and hydroiodic acid.

Effect of Weight Ratio of Graphene Oxide and Carbon Nanotubes on Electrochemical Performance of Planar On-Chip Micro-Supercapacitors

With the wide popularization of 5 G network, the application of miniaturized electronic equipment is being gradually developed, but limited by energy storage technology. Micro-supercapacitors (MSCs) have become the possible direction to solve this problem because of their unique properties. Graphene oxide and carbon nanotubes are very suitable materials for preparing MSCs. However, graphene oxide will overlap due to van der Waals force, and carbon nanotubes will be entangled. In order to solve these problems, reduced graphene oxide and carbon nanotube composite films were prepared by liquid-air interface self-assembly and hydroiodic acid reduction. Planar MSCs with weight ratios of 5:1, 10:1 and 15:1 were prepared by photolithography, and the MSCs of 15:1 show the best comprehensive performance with the area capacitance of 0.905 μF cm−2, the energy density of 0.125 nWh cm−2, the power density of 2263.31 nW cm−2, the time constant of 38 ms, and the capacitance retention of 91.2%.

Planar on-chip micro-supercapacitors based on reduced graphene oxide and carbon nanotube by liquid–air interface self-assembly and photolithography

Recently, the development of miniaturized electronic devices has accelerated the demand for the rate capability of planar on-chip micro-supercapacitors (POMSs). The POMSs based on reduced graphene oxide and carbon nanotube (rGO/CNT) composite electrodes (rGO/CNT-POMSs) were manufactured in the work and detailed electrochemical tests of devices were carried out over a wide range of scanning rates (0.01–10000 V s−1). The rGO/CNT composite electrode films without binder were prepared on silicon substrates by a modified liquid–air interface self-assembly method and a hydroiodic acid reduction method. The electrodes were fabricated into interdigital structure with 50 μm width of electrode and gap of electrode by photolithography. Interdigital POMSs based on different electrodes were prepared by gold sputtering on the electrode lugs. The area capacitance of the rGO/CNT-POMSs was 28.62 μF cm−2. They also had 0.004 μWh cm−2 of energy density and 1.068 μW cm−2 of power density. In addition, the charge–discharge time constant of the device was only 5.6 μs, and the charge–discharge rate was very quick. After 10,000 cycles of charge–discharge, the capacitance retention rate was still above 88%. At the ultra-high scan rate of 10000 V s−1, the devices still worked well. Compared with the POMSs based on reduced graphene oxide electrodes (rGO-POMSs) and the POMSs based on carbon nanotube electrodes (CNT-POMSs), the introduction of the CNT significantly increased the area capacitance, energy density and power density of rGO/CNT-POMSs, and significantly shortened the charge–discharge time constant. This indicated that the rGO/CNT composite electrodes had a good application prospect in the micro-chip accumulator devices.

Graphene-Enhanced Ion Transport in Dual-Conducting Composite Films of Polyacetylene and an Imidazolium Iodide Ionic Liquid

Dual-conducting polymer films were synthesized by dispersing graphene in an aqueous solution of poly(vinyl alcohol) and 1-propyl-3-methylimidazolium iodide ([C3mim]I) ionic liquid and thermally converting the poly(vinyl alcohol) to polyene in the presence of hydroiodic acid catalyst. The electrical and mechanical properties of the resulting free-standing films of the nanocomposite, containing different concentrations of graphene, were analyzed using electrochemical impedance spectroscopy (EIS) and dynamic mechanical analysis (DMA), respectively. Nyquist plots (imaginary vs real components of the frequency-dependent impedance) showed two characteristic arcs representing the composite's electronic and ionic conduction pathways. The conductivity values corresponding to both charge transport mechanisms increased with temperature and the graphene concentration. The enhancement in electronic conductivity is expected because of graphene's high electron mobility. Interestingly, ionic conductivity also showed a significant increase with graphene concentration, approximately triple the extent of the rise in the electronic conductivity, even though the loss and storage moduli of the films increased. (Generally, a higher modulus results in lower ionic conductivities in ionic gels.) Molecular dynamics simulations of the three-component system provided some insights into this unusual behavior. Mean square displacement data showed that the diffusion of the iodide anions was relatively isotropic. The iodide diffusion coefficient was higher in a blend with 5 vol % graphene than in blends with 3 vol % graphene or no graphene. The improvement is attributed to the interfacial effects of the graphene on the free volume of the blend. Furthermore, an exclusion of the iodide ions from the vicinity of graphene was observed in the radial distribution function analysis. The increase in the effective concentration of iodide due to this exclusion and the increase in its diffusion coefficient because of the excess free volume are the primary reasons for the observed enhancement in ionic conductivity by adding graphene.

Regulation of Quantum Wells Width Distribution in Quasi-2D Perovskite Films for High-Performance Photodetectors.

Dynamic optimization of the quantum-well (QW) width distribution in quasi-2D halide perovskite thin films is an effective approach for tuning the properties of photoelectric devices. Here, that the QWs width distribution in quasi-2D perovskite films can be controlled only by using hydroiodic acid (HI) as an additive is demonstrated. A uniform distribution of the colloidal particle size in the quasi-2D perovskite precursor solution is achieved through the formation of soluble iodoplumbate coordination complexes, PbI3 - from the reaction of HI with PbI2 , resulting in an improved phase purity in the final film. Density functional theory calculations indicate that the ideal n value quasi-2D perovskite reaction pathway through the PbI3 - complex has a lower enthalpy of formation than the random nucleation pathway without the HI additive. Benefiting from this merit, a high-quality quasi-2D perovskite film with optimized phase purity delivered a balanced carrier diffusion length and improved carrier mobility. The resultant photodetectors exhibited a light on/off ratio of 50000, a responsivity of 0.96 A W-1 , and a detectivity of 5.7 × 1012 Jones at 532nm. In addition, the state-of-the-art device maintained more than 80% of its initial photocurrent after 720h of storage at 30% relative humidity.

In-situ construction of lead-free halide perovskite CsCu2I3/g-C3N4 heterojunction for photocatalytic H2 generation

Lead-free halide perovskites have enormous superiority in photoelectric devices, but low photocatalytic hydrogen evolution (PHE) hinders their application in photocatalysis. Here, a heterojunction composed of CsCu2I3 (CCI) perovskite and graphite carbon nitride (CN) is constructed by in-situ hot-injection method for the first time. The resultant CCI/CN presents a significantly enhanced PHE performance from hydroiodic acid (HI) splitting with a PHE rate of 2212 umol/g/h, which is four times higher than CCI and nearly ten times higher than CN. It is revealed that a unique N-I bond is formed by the connection of N in CN and I in CCI at the interface between CN and CCI, which serves as a fast channel for the transfer of photogenerated electrons to establish a type II mechanism, effectively promoting the PHE performance. This study provides ideas and methods for the construction of type II photocatalyst for hydrogen production using lead-free halide perovskite.

Anisole-based assessment for the quantification of methoxyl groups in lignin-rich biomass

The methoxyl group (–OCH3) is abundant in biomass containing lignin. The quantification and biogeochemical evolution features of –OCH3 in these materials are still a research focus. The quantification methods of –OCH3 available up to date overall have a large error range and/or are time consuming through the need for a series of treatments. The present work reports an anisole-based assessment method for –OCH3 quantification in biomass containing lignin, by applying an anisole standard reagent to react with hydroiodic acid to create an external quantification curve used for –OCH3 quantification in samples studied. In practice, 10–200 μL of anisole and 0.2–1 g of lignite samples were reacted with surplus hydroiodic acid under 130 ℃ for 30 min to quantitatively obtain the iodomethane (CH3I) produced in a 20 mL ampere vial. The headspace gas was subjected to GC-FID analysis to create an external calibration curve for –OCH3 quantification in the lignite samples. The results indicated that the external calibration curve had a fairly good correlative relationship (R2 = 0.9523). Quantification of –OCH3 carbon in lignites by this method is well within the scope of previous reports. It seems likely that this simple and precise quantification method will have promising applications for methoxyl group quantification in lignin-rich biomass.

Maintaining Colloidal Stability of Polymer/Reduced Graphene Oxide Nanocomposite Aqueous Dispersions Produced via In Situ Reduction of Graphene Oxide for the Preparation of Electrically Conductive Coatings

Chemical reduction of graphene oxide (GO) in an aqueous polymer/GO dispersion invariably causes restacking and precipitation of reduced GO (rGO) sheets leading to spontaneous phase separation. This has been a significant challenge limiting the commercial production of aqueous polymer/rGO paints and coatings. In this study, we developed in situ reduction strategies to chemically reduce GO while maintaining the colloidal stability of an aqueous polymer/rGO dispersion. An aqueous polymer/GO latex was prepared using miniemulsion polymerization, which was subsequently reduced in situ using four different chemical reducing agents (hydroiodic acid, sodium borohydride, ascorbic acid, and hydrazine hydrate) to obtain colloidally stable polymer/rGO dispersions. The reduction of GO was confirmed using X-ray photoelectron spectroscopy (XPS), Raman, and X-ray diffraction (XRD). The colloidal stability of the reduced dispersions was maintained for over 6 months under ambient storage conditions. Stable polymer/rGO dispersions were drop cast to form nanocomposite films at ambient temperature. Finally, the electrical conductivity measurement of polymer/rGO films revealed the highest conductivity for hydrazine hydrate-reduced films (∼6.6 S m–1), which was marginally higher than for hydroiodic acid-reduced films (∼3.4 S m–1). The electrical conductivity of sodium borohydride- and ascorbic acid-reduced films was two orders of magnitude lower than for hydrazine hydrate- and hydroiodic acid-reduced films. Overall, the present results pave a path for the commercial production of colloidally stable aqueous polymer/rGO composite paints and coatings.

PEA2PbI4: fast two-dimensional lead iodide perovskite scintillator with green and red emission

Among the two-dimensional hybrid organic-inorganic perovskites, PEA2PbBr4 is one of the best scintillators combining high light yield and fast nanosecond decay time. However, it has limited sensitivity to X-ray and positron emission tomography because of insufficient mass density and effective atomic number. In this article, we show that exchanging the halide from bromide to iodide allows to shorten the absorption length as much as two times for X-ray energies. We present a detailed study on scintillation properties of self-grown samples of PEA2PbI4 crystal, which we compare with the previously reported results for PEA2PbBr4 crystal. The synthesis method of PEA2PbI4 crystal is based on dissolving the perovskite precursors in hydroiodic acid, which is then stirred and left for evaporation. Our measurements include the characterizations with optical, X-ray, and γ-ray sources. We observe two emission bands of PEA2PbI4 crystal centered at 532 (green) and 660 (red) nm, and we link them to the scintillation mechanisms involving exciton and surface defect states. We also report the scintillation light yields of 1,000 and 10,000 photons/MeV at room temperature and 10 K, respectively, and the coincidence timing resolution full width at half maximum of 138 ps, and the fast component in scintillation decay curve of 0.5 ns. This fast component is much faster than that of 13.4 ns of PEA2PbBr4 crystal, and with two times shorter absorption length, it secures better opportunities in timing applications in particular time-of-flight positron emission tomography and high energy physics.

Efficient Synthesis of 3-Mercaptoindoles via HI-Promoted Sulfenylation of Indoles with Sodium Sulfinates.

A new direct sulfenylation method of indoles by sodium sulfinates and hydroiodic acid was developed giving variety of 3-sulfenylindoles in high yields under mild conditions without using any catalysts or other additives. In situ-generated RS-I species are supposed to be mainly responsible for the key electrophilic alkyl- or aryl-thiolation process.

Tunable Interlayer Interactions in Reduced Graphene Oxide Paper.

Free-standing graphene-based paper-like materials have garnered significant interest for various applications because of their tunable physical and chemical properties, along with unique multilayered structures. Because of the layered configuration of graphene paper, characterization of the interactions between graphene sheets is critical for understanding its fundamental properties and applications. We investigate the interlayer cohesion energies in graphene papers using the mode I fracture concept with double cantilever beam specimens. Mechanical separation along the middle of the graphene paper thickness enables the evaluation of interlayer bonding strength in the paper. Starting from graphene oxide paper, the chemical reduction using hydroiodic acid tunes the interlayer cohesion energy from 11.30 ± 0.25 to 4.78 ± 0.18 J/m2 as the reduction time increases. The interlayer cohesion energy is correlated with the oxygen content, interlayer spacing, and electrical conductivity of graphene papers. This work provides a fundamental characterization of the interlayer cohesion energy of graphene paper and establishes the potential for tunability of the interlayer interactions in graphene paper.

Highly thermally conductive and flexible reduced graphene oxide films produced using two-step liquid-phase repairing method with hydriodic acid

Highly thermally conductive and flexible reduced graphene oxide films produced using two-step liquid-phase repairing method with hydriodic acid

Surface polarization-induced emission and stability enhancement of CsPbX3 nanocrystals.

Recently, the polarization effect has been receiving tremendous attention, as it can result in improved stability and charge transfer efficiency of metal-halide perovskites (MHPs). However, realizing the polarization effect on CsPbX3 NCs still remains a challenge. Here, metal ions with small radii (such as Mg2+, Li+, Ni2+, etc.) are introduced on the surface of CsPbX3 NCs, which facilitate the arising of electric dipole and surface polarization. The surface polarization effect promotes redistribution of the surface electron density, leading to reinforced surface ligand bonding, reduced surface defects, near unity photoluminescence quantum yields (PLQYs), and enhanced stability. Moreover, further introduction of hydroiodic acid results in the in situ formation of tert-butyl iodide (TBI), which facilitates the successful synthesis of pure iodine-based CsPbI3 NCs with high PLQY (95.3%) and stability under ambient conditions. The results of this work provide sufficient evidence to exhibit the crucial role of the surface polarization effect, which promotes the synthesis of high-quality MHPs and their applications in the fields of optoelectronic devices.

Aramid Nanofibers/Reduced Graphene Oxide Composite Electrodes with High Mechanical Properties

In this work, aramid nanofibers (ANFs)/reduced graphene oxide (ANFs/RGO) film electrodes were prepared by vacuum-assisted filtration, followed by hydroiodic acid reduction. Compared with thermal reduced ANFs/RGO, these as-prepared film electrodes exhibit a combination of mechanical and electrochemical properties with a tensile strength of 184.5 MPa and a volumetric specific capacitance of 134.4 F/cm3 at a current density of 0.125 mA/cm2, respectively. In addition, the film electrodes also show a superior cycle life with 94.6% capacitance retention after 5000 cycles. This kind of free-standing film electrode may have huge potential for flexible energy-storage devices.

Reaction of Bi(NO3)3 with quinoxaline in the presence of HI. Synthesis of 5,6,7,8-tetranitro-1,2,3,4-tetrahydroquinoxaline-2,3-diol by serendipity: Crystal structure, Hirshfeld and optical study of a novel energetic compound

Treatment of an acetone solution of Bi(NO3)3 with quinoxaline (Qx) in the presence of hydroiodic acid produces in moderate yield the crystallographically characterized 1D-polymeric salt-like iodobismutate [(Qx-H+)BiI4]n (1), whose negative charge is balanced by mono-protonated quinoxalinium counterions. The main product is an unusual tetra(nitrated) quinoxaline derivative, namely 5,6,7,8-tetranitro-1,2,3,4-tetrahydroquinoxaline-2,3-diol (2), which was formed accidently under mild reaction conditions. The molecular structure of this organic compound 2 was determined by single-crystal X-ray diffraction and its strong intermolecular interactions giving rise to a supramolecular three-dimensional network were assessed by IR spectroscopy and a Hirshfeld surface analysis. Structural analysis reveals that the crystal structure is supported essentially by O‒H···O and N‒H···O intermolecular hydrogen bonds and additionally stabilized by N‒O···π interactions. The ground-state molecular structure of this novel organic heterocycle has been optimized by DFT calculation. The optical band gap, caused by intramolecular charge transfer (ICT) from the 1,2,3,4-tetrahydroquinoxaline-2,3-diol fragment to the nitro groups, has been estimated to be 2.04 eV. High density, positive heat of formation and very good thermal stability according to thermal analysis by TGA, DTA and DSC characterize tetranitro compound 2 as energetic material.

Synthesis and structural characterisation of trivalent halidoantimonates and bismuthates of 2-methyl-2-benzoxazole (box): Reactivity and solid-state structural diversity within the [MX(6 – n)] [boxH](3 – n) series (M = Sb or Bi; X = Cl, Br, I; n = 0 or 1)

The structural characterisation (X-ray diffraction) of a series of anionic antimony (III) and bismuth (III) halide complexes containing protonated 2-methyl-1,3-benzoxazole (boxH) countercations are reported. Treatment of aqueous strong acid (HCl or HBr) or strong acid/additional solvent mixtures of box with MX3 (M = Sb, Bi; X = Cl, Br) leads to the isolation of known compounds BiCl5(boxH)2 (6: 33%) and SbBr5(boxH)2 (7: 31%) and the novel material BiBr5(boxH)2 (8: 57%). In the solid state, 6–8 all display an anionic portion consisting of edge sharing infinite zig-zag chains of the metallic [(MX5)2–]∞ units classified as Type A in structure. In contrast, mixtures of box, conc. HCl and SbCl3 yield, following recrystallization, to small quantities of Sb2OCl6(boxH)2 (2: 0.4%); a hitherto unknown complex containing the less common Sb2OCl62− anion. Hypotheses as to the origin of 2 are presented including its formation by hydrolysis of known SbCl4(boxH). Hydroiodic acid solutions of box treated with SbI3 leads to the isolation of the SbI6(boxH)3·(H2O) (9: 42%) which displays a rare example of the isolated SbI63− anion. The treatment BiI3 under similar conditions leads to the precipitation of previously known Bi2I9(boxH)3 (10: 54%) as a major product. Further evaporation of the reaction mixture from which 10 was obtained yields a second minor product, 11 (3%), identified as the Bi analogue of 9: BiI6(boxH)3·(H2O). The species described herein are further discussed in terms of their general coordination properties and relevance to related complexes under current scrutiny for their solid-state materials properties.

Enhanced room-temperature reduction of graphene oxide using Al as a supplement in the liquid phase HI

Chemical reduction of graphene oxide has emerged as one of the most suitable processes for low-cost and large-scale production of graphene for potential applications. Here we report a simple, efficient, scalable, room-temperature method for enhanced reduction of graphene oxide (GO). Nowadays, hydroiodic acid (HI) is being widely used as a reducing agent for synthesizing highly conductive reduced graphene oxide. Herein, aluminum (Al) powder was used in the second step to improve the extent of reduction using HI. Al3+, which is a strong lewis acid, helps further in the reduction and enhances the one-step reduction by HI. Field Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD), Raman and X-Ray Photoelectron Spectroscopy (XPS) confirmed the formation of GO and assisted in understanding the potential of HI and Al–HI as reducing agents. The comparative analysis demonstrates the enhancement in the reduction properties of the novel Al supplemented reduced GO. Additionally, an electrically conductive dip-coated film with a sheet resistance of 4.56 × 104 Ω/sq was successfully fabricated using this Al-supplemented reduction technique.

Boosting the storage capacity and the rate capability of flexible graphene film via a nondestructive thermo-chemical reduction

Tuning the electrical conductivity, the porosity, and the surface chemistry of a flexible graphene film (FGF) without damaging its integrity is pivotal to boost its charge storage capacity and rate capability toward supercapacitor application. In this perspective, we herein propose a two-step non destructive reduction approach to adjust the physicochemical properties of the FGF; the first step involves a chemical reduction by hydroiodic acid (HI), and the second step implicates a thermal treatment under ambient air. The impact of the two-step thermo-chemical reduction on the structure, the porosity, the electrical conductivity, and the capacitive behavior of the FGF are scrutinized by a series of relevant characterizations. It is found that the chemical treatment enables a high electrical conductivity, improved thermal stability, and enhanced capacitance due to the presence of iodine/iodide ions on the FGF's surface. Moreover, thermal treatment at 450 °C increases the specific surface area, introduces oxygen functional groups into the surface, and improves the surface wettability of the FGF. Hence, the as-prepared FGF electrode delivers a remarkable specific capacitance of 350.44 F·g−1 at 0.5 A·g−1 with excellent rate capability of 219.60 F·g−1 at 10 A·g−1. The FGF based symmetric supercapacitor attains a high energy density of 12.82 W·h·kg−1 at a power density of 125 W·kg−1 and retains an energy density of 9,51 W·h·kg−1 as the power density reaches 2500 W·kg−1.