Showing papers on "Iodide published in 2020"
TL;DR: Modifying the defective surface of perovskite films with cadmium iodide (CdI2) effectively reduces the degree of surface iodine deficiency, and stabilizes iodine ions via the formation of strong Cd-I ionic bonds, which largely reduces the interfacial charge recombination loss.
Abstract: State-of-the-art, high-performance perovskite solar cells (PSCs) contain a large amount of iodine to realize smaller bandgaps. However, the presence of numerous iodine vacancies at the surface of the film formed by their evaporation during the thermal annealing process has been broadly shown to induce deep-level defects, incur nonradiative charge recombination, and induce photocurrent hysteresis, all of which limit the efficiency and stability of PSCs. In this work, modifying the defective surface of perovskite films with cadmium iodide (CdI2) effectively reduces the degree of surface iodine deficiency and stabilizes iodine ions via the formation of strong Cd-I ionic bonds. This largely reduces the interfacial charge recombination loss, yielding a high efficiency of 21.9% for blade-coated PSCs with an open-circuit voltage of 1.20 V, corresponding to a record small voltage deficit of 0.31 V. The CdI2 surface treatment also improves the operational stability of the PSCs, retaining 92% efficiency after constant illumination at 1 sun intensity for 1000 h. This work provides a promising strategy to optimize the surface/interface optoelectronic properties of perovskites for more efficient and stable solar cells and other optoelectronic devices.
195 citations
TL;DR: This work systematically reveals the parasitic influence of free water and iodine species to the Zn anode, but also provides an efficient strategy to develop long-life aqueous Zn-I2 batteries.
Abstract: The introduction of the redox couple of triiodide/iodide (I3 - /I- ) into aqueous rechargeable zinc batteries is a promising energy-storage resource owing to its safety and cost-effectiveness. Nevertheless, the limited lifespan of zinc-iodine (Zn-I2 ) batteries is currently far from satisfactory owing to the uncontrolled shuttling of triiodide and unfavorable side-reactions on the Zn anode. Herein, space-resolution Raman and micro-IR spectroscopies reveal that the Zn anode suffers from corrosion induced by both water and iodine species. Then, a metal-organic framework (MOF) is exploited as an ionic sieve membrane to simultaneously resolve these problems for Zn-I2 batteries. The multifunctional MOF membrane, first, suppresses the shuttling of I3 - and restrains related parasitic side-reaction on the Zn anode. Furthermore, by regulating the electrolyte solvation structure, the MOF channels construct a unique electrolyte structure (more aggregative ion associations than in saturated electrolyte). With the concurrent improvement on both the iodine cathode and the Zn anode, Zn-I2 batteries achieve an ultralong lifespan (>6000 cycles), high capacity retention (84.6%), and high reversibility (Coulombic efficiency: 99.65%). This work not only systematically reveals the parasitic influence of free water and iodine species to the Zn anode, but also provides an efficient strategy to develop long-life aqueous Zn-I2 batteries.
157 citations
TL;DR: It is shown that the inherently low ionization potential of MASnI3 is solely responsible of the high stability of tin vacancy and interstitial iodine defects, which are in turn at the origin of the material p-doping, and tin chemistry dominates tin-iodide perovskites defect chemistry.
Abstract: Tin halide perovskites make up the only lead-free material class endowed with optoelectronic properties comparable to those of lead iodide perovskites. Despite significant progress, the device effi...
104 citations
TL;DR: The key to produc-tive, selective cross-coupling is the use of a small amount of iodide or bromide along with a recently reported ligand, pyridine-2,6-bis(N-cyanocarboxamidine) (PyBCamCN).
Abstract: Alkyl chlorides and aryl chlorides are among the most abundant and stable carbon electrophiles. Although their coupling with carbon nucleophiles is well developed, the cross-electrophile coupling of aryl chlorides with alkyl chlorides has remained a challenge. We report here the first general approach to this transformation. The key to productive, selective cross-coupling is the use of a small amount of iodide or bromide along with a recently reported ligand, pyridine-2,6-bis(N-cyanocarboxamidine) (PyBCamCN). The scope of the reaction is demonstrated with 35 examples (63 ± 16% average yield), and we show that the Br- and I- additives act as cocatalysts, generating a low, steady-state concentration of more-reactive alkyl bromide/iodide.
92 citations
TL;DR: In this paper, the methylammonium and formamidinium-mixed organic cation perovskite solution was used as a stabilizer to restrain the deprotonation of methymmonium iodide in the precursor solutions.
84 citations
TL;DR: The development of MOFs with cross linked chitosan as a promising adsorbent material for the remediation of environmental water polluted by iodine and shows chemical and thermal stability, high removal efficiency for capture of iodine from wastewater and furthermore good recyclability.
78 citations
TL;DR: A Ti3C2Tx MXene foam with a three-dimensional hierarchical porous architecture is proposed as a cathode-electrolyte interface layer in Li-I2 batteries, enabling high-rate and ultra-stable cycling performance at a high iodine content and loading mass.
Abstract: Lithium-iodine (Li-I2) batteries are promising candidates for next-generation electrochemical energy storage systems due to their high energy density and the excellent kinetic rates of I2 cathodes. However, dissolution of iodine and iodide has hindered their widespread adoption for practical applications. Herein, a Ti3C2Tx MXene foam with a three-dimensional hierarchical porous architecture is proposed as a cathode-electrolyte interface layer in Li-I2 batteries, enabling high-rate and ultrastable cycling performance at a high iodine content and loading mass. Theoretical calculations and empirical characterizations indicate that Ti3C2Tx MXene sheets with high metallic conductivity not only provide strong chemical binding with iodine species to suppress the shuttle effect but also facilitate fast redox reactions during cell cycling. As a result, the Li-I2 battery using a cathode with 70 wt % I2 cycled stably for over 1000 cycles at a rate of 2 C, even at an ultrahigh loading mass of 5.2 mg cm-2. To the best of the authors' knowledge, this is the highest reported loading at such a high iodine content. This work suggests that using a Ti3C2Tx MXene interface layer can enable the design and application of high-energy Li-I2 batteries.
76 citations
TL;DR: In this paper, the performance of new synthesized ionic liquids derived from pyridine, namely: 1-ethyl-4-(2-(4-fluorobenzylidene)hydrazine carbonyl)pyridin-1-ium iodide (IPyrC2H5), and 1-butyl-4(2.4)-4-(1.5)-hexane-hexane (hexane)-hexadecane(hexane), were investigated against mild steel corrosion in 1-M HCl by using electrochemical methods
75 citations
TL;DR: In this paper, liquid complexes that are formed from biimidazole-based porous organic polymers (TBIM and HBIM) and polyiodide ions were reported.
Abstract: In the recent years, considerable progress has been made in iodine uptake—a radioactive emission process accompanying nuclear fission with porous organic polymers (POPs). However, all the resulting complexes of the cationic backbone of POPs and polyiodides are in the solid state. Here, we report, for the first time, liquid complexes that are formed from biimidazole-based POPs (TBIM and HBIM) and polyiodide ions. Interestingly, both TBIM and HBIM have excellent adsorption properties toward iodine with 9.43 and 8.11 g g−1, respectively. As far as we know, these are the highest adsorption values among all the POPs reported until now. Furthermore, TBIM and HBIM can sense both I2 and nitroaromatic compounds (NACs, such as picric acid/p-nitrophenol) via fluorescence quenching. In particular, TBIM has high fluorescence sensing performance toward iodine with the Stern–Volmer quenching constants (Ksv) of 1.16 × 104 L mol−1 and limit of detection (LOD) of 1.29 × 10−10 mol L−1.
67 citations
TL;DR: It is reported that the large di-cation aminomethylpyridinium (AMPY), can template novel 3D structures which resemble conventional perovskites, and these compounds are indirect-bandgap semiconductors with direct bandgaps presenting at slightly higher energies and dispersive electronic bands.
Abstract: Large organic A cations cannot stabilize the 3D perovskite AMX3 structure because they cannot be accommodated in the cubo-octhedral cage (do not follow the Goldschmidt tolerance factor rule), and t...
66 citations
TL;DR: A nickel-catalyzed reductive cross-coupling reaction of easily accessible 3-butenyl carbamoyl chloride with primary alkyl iodide to access the chiral α-alkylated pyrrolidinone with broad substrate scope and high ee is reported.
Abstract: Herein, we report a nickel-catalyzed reductive cross-coupling reaction of easily accessible 3-butenyl carbamoyl chloride with primary alkyl iodide to access the chiral α-alkylated pyrrolidinone wit...
TL;DR: The main advantage of this triazole‐substituted chiral aryl iodide is the excellent performance in a plethora of mechanistically diverse enantioselective transformations, such as spirocyclizations, phenol dearomatizations, α‐oxygenations, and oxidative rearrangements.
Abstract: A widely applicable triazole-substituted chiral aryl iodide is described as catalyst for enantioselective oxidation reactions. The introduction of a substituent in ortho-position to the iodide is key for its high reactivity and selectivity. Besides a robust and modular synthesis, the main advantage of this catalyst is the excellent performance in a plethora of mechanistically diverse enantioselective transformations, such as spirocyclizations, phenol dearomatizations, α-oxygenations, and oxidative rearrangements. DFT-calculations of in situ generated [hydroxy(tosyloxy)iodo]arene isomers give an initial rational for the observed reactivity.
TL;DR: The novel iodine-rich iodobismuthates(III) and halometalate anions reveal narrow optical band gaps and fairly high thermal stability, favoring their potential use in photovoltaic devices.
Abstract: Reactions of BiI3, I2, and iodide salts of two different pyridinum cations result in the formation of the novel iodine-rich iodobismuthates(III) (1,3-MePy)4{[Bi4I16](I2)} (1) and (1-MePy){[BiI4](I2)0.5) (2), where the halometalate anions are connected by diiodine linkers into one- or two-dimensional supramolecular structures. Both complexes reveal narrow optical band gaps and fairly high thermal stability, favoring their potential use in photovoltaic devices.
TL;DR: The combined iodine K-edge extended X-ray absorption fine structure (EXAFS) spectra and first-principles calculations using density functional theory (DFT) suggested that IO3- was stabilized in ettringite by hydrogen bonding and electrostatic forces, providing valuable insight into the long-term stabilization of anionic iodine species and their migration in cementitious nuclear waste repository or alkaline environments.
TL;DR: In this article, the authors report the enantioselective formal transfer of a carbamoyl iodide across a 1,1-disubstituted styrene using Ni-catalysis.
Abstract: This work reports the enantioselective formal transfer of a carbamoyl iodide across a 1,1-disubstituted styrene using Ni-catalysis. Employing an air-stable Ni(II) precatalyst and a commercially ava...
TL;DR: In this paper, a photocontrolled iodide-mediated reversible deactivation radical polymerization (RDRP) of methacrylates, without an external photocatalyst, was developed using an alkyl iodide (e.g., 2-iodo-2-methylpropionitrile) as the initiator at room temperature.
Abstract: Herein, near-infrared (NIR) photocontrolled iodide-mediated reversible-deactivation radical polymerization (RDRP) of methacrylates, without an external photocatalyst, was developed using an alkyl iodide (e.g., 2-iodo-2-methylpropionitrile) as the initiator at room temperature. This example is the first use of a series of special solvents containing carbonyl groups (e.g., 1,3-dimethyl-2-imidazolidinone) as both solvent and catalyst for photocontrolled RDRP using long-wavelength (λmax =730 nm) irradiation. The polymerization system comprises monomer, alkyl iodide initiator, and solvent. Well-defined polymers were synthesized with excellent control over the molecular weights and molecular weight distributions (Mw /Mn <1.21). The living features of this system were confirmed by polymerization kinetics, multiple controlled "on-off" light switching cycles, and chain extension experiments. Importantly, the polymerizations proceeded successfully with various barriers (pork skin and A4 paper), demonstrating the advantage of high-penetration NIR light.
TL;DR: In this article, Methylammonium (MA) and lead halide perovskites have been used as candidate materials for high-performing solar cells, but show serious issues related to long-term stability.
Abstract: Lead halide perovskites have rapidly emerged as candidate materials for high-performing solar cells, but show serious issues related to long-term stability. Methylammonium (MA) lead perovskites wit...
TL;DR: In this article, the authors systematically evaluated nanostructured layered double hydroxide (LDH) materials comprised of MgFe or CoCr with variable M2+:M3+ molar ratios for their affinity for the environmentally-relevant anions of iodine including iodide (I−) and iodate (IO3−).
TL;DR: Under irradiation of 456 nm blue light-emitting diodes, PPh3 catalyzes the iododecarboxylation of aliphatic carboxylic acid derived N-(acyloxy)phthalimide with lithium iodide as an iodine source to allow various decarboxYLative transformations without using transition-metal or organic-dye-based photocatalysts.
TL;DR: An environment-friendly scaling-corrosion inhibitor composed of 10-methylacridinium iodide (MAI) and sodium citrate (SC) was developed, whose scale inhibition performance were studied through weight loss, electrochemical techniques, static tests and surface analysis techniques as discussed by the authors.
TL;DR: Changes in attempt frequency, activation entropy, and charge carrier concentration seem to be responsible for the increase in ionic conductivity of Argyrodite-type Li6PS5X compounds.
Abstract: Argyrodite-type Li6PS5X (X = Cl, Br) compounds are considered to act as powerful ionic conductors in next-generation all-solid-state lithium batteries. In contrast to Li6PS5Br and Li6PS5Cl compounds showing ionic conductivities on the order of several mS cm-1, the iodine compound Li6PS5I turned out to be a poor ionic conductor. This difference has been explained by anion site disorder in Li6PS5Br and Li6PS5Cl leading to facile through-going, that is, long-range ion transport. In the structurally ordered compound, Li6PS5I, long-range ion transport is, however, interrupted because the important intercage Li jump-diffusion pathway, enabling the ions to diffuse over long distances, is characterized by higher activation energy than that in the sibling compounds. Here, we introduced structural disorder in the iodide by soft mechanical treatment and took advantage of a high-energy planetary mill to prepare nanocrystalline Li6PS5I. A milling time of only 120 min turned out to be sufficient to boost ionic conductivity by 2 orders of magnitude, reaching σtotal = 0.5 × 10-3 S cm-1. We followed this noticeable increase in ionic conductivity by broad-band conductivity spectroscopy and 7Li nuclear magnetic relaxation. X-ray powder diffraction and high-resolution 6Li, 31P MAS NMR helped characterize structural changes and the extent of disorder introduced. Changes in attempt frequency, activation entropy, and charge carrier concentration seem to be responsible for this increase.
TL;DR: In this article, a mechanism for describing the corrosion inhibition of API 5L X52 steel in 1 M H2SO4 employing two ionic liquids (ILs) with imidazolium-derived cations and iodide anion as corrosion inhibitors (CIs) at stationary and dynamic states is proposed.
TL;DR: The preparation of black formamidinium lead iodide (FAPbI3) requires high-temperature annealing and the incorporation of smaller A-site cations, such as methylammonium (MA+), cesium, or rubidium as mentioned in this paper.
Abstract: Preparation of black formamidinium lead iodide (FAPbI3) requires high-temperature annealing and the incorporation of smaller A-site cations, such as methylammonium (MA+), cesium, or rubidium. A maj...
TL;DR: Surface ligand treatment provides a promising approach for passivating defect states, improving material and device stability, manipulating interfacial energetics, and improving the performance of....
Abstract: Surface ligand treatment provides a promising approach for passivating defect states, improving material and device stability, manipulating interfacial energetics, and improving the performance of ...
TL;DR: It is shown that electrochemical oxidation of iodide in nanoporous carbons forms persistent solid iodine deposits and strategies for improved iodine pore filling capacity and prevention of self-discharge, applicable to hybrid supercapacitors and batteries are demonstrated.
Abstract: Aqueous iodine based electrochemical energy storage is considered a potential candidate to improve sustainability and performance of current battery and supercapacitor technology. It harnesses the redox activity of iodide, iodine, and polyiodide species in the confined geometry of nanoporous carbon electrodes. However, current descriptions of the electrochemical reaction mechanism to interconvert these species are elusive. Here we show that electrochemical oxidation of iodide in nanoporous carbons forms persistent solid iodine deposits. Confinement slows down dissolution into triiodide and pentaiodide, responsible for otherwise significant self-discharge via shuttling. The main tools for these insights are in situ Raman spectroscopy and in situ small and wide-angle X-ray scattering (in situ SAXS/WAXS). In situ Raman confirms the reversible formation of triiodide and pentaiodide. In situ SAXS/WAXS indicates remarkable amounts of solid iodine deposited in the carbon nanopores. Combined with stochastic modeling, in situ SAXS allows quantifying the solid iodine volume fraction and visualizing the iodine structure on 3D lattice models at the sub-nanometer scale. Based on the derived mechanism, we demonstrate strategies for improved iodine pore filling capacity and prevention of self-discharge, applicable to hybrid supercapacitors and batteries. Iodide based energy storage is a potential candidate to improve performance of hybrid supercapacitors and batteries. Here, the authors revisit the previous understanding and show that electrochemical oxidation of iodide results in solid iodine deposits stabilized by the confinement of nanoporous carbons.
TL;DR: Visible light irradiation of a mixed halide perovskite film in contact with a solvent (dichloromethane, DCM) in which the film otherwise is stable leads to selective expulsion of iodide (I) from th...
Abstract: Visible light irradiation of a mixed halide perovskite film in contact with a solvent (dichloromethane, DCM) in which the film otherwise is stable leads to selective expulsion of iodide (I) from th...
TL;DR: In this paper, the adsorption and corrosion inhibition behavior of three dihydropyrimidinone (DHPM) derivatives on carbon steel in 0.5 m sulphuric acid solution is investigated.
TL;DR: Reduction of the aluminum iodide AlI2AriPr8 with 5% w/w Na/NaCl in hexanes gave a dark red solution from which the monomeric alanediyl :Al AriPr8 was isolated in ca.
Abstract: Reduction of the aluminum iodide AlI2AriPr8 (1; AriPr8 = C6H-2,6-(C6H2-2,4,6-Pri3)2-3,5-Pri2) with 5% w/w Na/NaCl in hexanes gave a dark red solution from which the monomeric alanediyl :AlAriPr8 (2) was isolated in ca. 28% yield as yellow-orange crystals. Compounds 1 and 2 were characterized by X-ray crystallography, electronic and NMR spectroscopy, and theoretical calculations. The Al atom in 2 is one-coordinate, and the compound displays two absorptions in its electronic spectrum at 354 and 455 nm. It reacts with H2 under ambient conditions to give the aluminum hydride {AlH(μ-H)AriPr8}2, probably via a weakly bound dimer of 2 as an intermediate.