Anions Cl Research Articles

Dendrite-free and stable zinc-ion batteries enabled by a cation-anion synergistic regulation additive

Dendrite growth and parasitic reactions in Zn anodes limit the implementation of aqueous zinc ion batteries (AZIBs). Here, tetraethyl ammonium chloride (TEAC) is proposed as an effective, nontoxic and bi-functional electrolyte additive during the Zn plating/striping to suppress the growth of dendrite and by-products in AZIBs. Benefiting from its inherent surfactant properties, the preferential adsorption of cations TEA+ on the Zn anode surface facilitates the uniform Zn deposition and restrains the dendrite growth, while the anions Cl− promote the ions transport and reduce the battery polarization. The synergistic regulation of cation and anion enable the Zn||Zn symmetric cells outstanding cycling stability over 2450 h and 1600 h at 1 mA cm−2 and 5 mA cm−2, respectively. Additionally, Zn||MnO2 full cells exhibit high-capacity retention of 88% after 2000 cycles at 3 A g−1. This work provides a promising approach of synergistic regulation with cation and anion of electrolyte additives to promote the stability of Zn anode for high-performance AZIBs batteries.

Photochemical outcomes triggered by gold shell-isolated nanorods on bioinspired nanoarchitectonics for bacterial membranes

Boosted by the indiscriminate use of antibiotics, multidrug-resistance (MDR) demands new strategies to combat bacterial infections, such as photothermal therapy (PTT) based on plasmonic nanostructures. PTT efficiency relies on photoinduced damage caused to the bacterial machinery, for which nanostructure incorporation into the cell envelope is key. Herein, we shall unveil the binding and photochemical mechanisms of gold shell-isolated nanorods (AuSHINRs) on bioinspired bacterial membranes assembled as Langmuir and Langmuir-Schaefer (LS) monolayers of DOPE, Lysyl-PG, DOPG and CL. AuSHINRs incorporation expanded the isotherms, with stronger effect on the anionic DOPG and CL. Indeed, FTIR of LS films revealed more modifications for DOPG and CL owing to stronger attractive electrostatic interactions between anionic phosphates and the positively charged AuSHINRs, while electrostatic repulsions with the cationic ethanolamine (DOPE) and lysyl (Lysyl-PG) polar groups might have weakened their interactions with AuSHINRs. No statistical difference was observed in the surface area of irradiated DOPE and Lysyl-PG monolayers on AuSHINRs, which is evidence of the restricted nanostructures insertion. In contrast, irradiated DOPG monolayer on AuSHINRs decreased 4.0 % in surface area, while irradiated CL monolayer increased 3.7 %. Such results agree with oxidative reactions prompted by ROS generated by AuSHINRs photoactivation. The deepest AuSHINRs insertion into DOPG may have favored chain cleavage while hydroperoxidation is the mostly like outcome in CL, where AuSHINRs are surrounding the polar groups. Furthermore, preliminary experiments on Escherichia coli culture demonstrated that the electrostatic interactions with AuSHINRs do not inhibit bacterial growth, but the photoinduced effects are highly toxic, resulting in microbial inactivation.

Evaluation of the Chemical Characteristics and Predictive Model of Water-Soluble Inorganic Ions for Fine Particulate Matter Generated in Pohang

Objectives:This study aims to contribute to establishing the regional effective management of fine particulate matter by evaluating the chemical characteristics and contribution of fine particulate matter, and the accuracy of predictive model of fine particulate matter through the measurement of water-soluble inorganic ions (WSIIs) and electrical conductivity for fine particulate matter generated in Pohang.Methods:PM<sub>10</sub> and PM<sub>2.5</sub> samples were simultaneously collected using a low volume air sampler from April to November 2022. For sample analysis, cations of Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup>, NH<sub>4</sub><sup>+</sup>, Na<sup>+</sup> and anions of Cl<sup>-</sup>, NO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2-</sup>, and electrical conductivity were measured after pretreatment by ultrasonic extraction. Results and Discussion:The average concentrations of WSIIs for PM<sub>10</sub> and PM<sub>2.5</sub> in Pohang were 12.1μg/m<sup>3</sup> and 8.5μg/m<sup>3</sup>, respectively, accounting for 35.5% and 50.0% of each fine particulate matter. The sum of NH<sub>4</sub><sup>+</sup>, NO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2-</sup> concentration was found to account for the majority of 71% and 78% of WSIIs in PM<sub>10</sub> and PM<sub>2.5</sub>, respectively. The PM<sub>2.5</sub>/PM<sub>10</sub> ratios for NH<sub>4</sub><sup>+</sup>, K<sup>+</sup>, and SO<sub>4</sub><sup>2-</sup> were 95%, 89%, and 81%, respectively, mostly present in PM<sub>2.5</sub>. The average ratio of PM<sub>2.5</sub>/PM<sub>10</sub> for NO<sub>3</sub><sup>-</sup> was 54%, but it rose sharply to 79% in November when the temperature was low, indicating an increase in contribution to the generation of PM<sub>2.5</sub> in winter. During the sampling period excluding April and July, the ion balance for cations and anions was relatively good at a 1:1 ratio and showed chemical properties of fine particulate matter close to neutral. A regression model was evaluated for the measured electrical conductivity of WSIIs and the concentration of fine particulate matter. The MAE and RMSE values for PM<sub>2.5</sub> were 1.8μg/m<sup>3</sup> and 2.4μg/m<sup>3</sup>, respectively, which were lower than PM<sub>10</sub> (MAE 7.5 μg/m<sup>3</sup>, RMSE 10.3μg/m<sup>3</sup>), indicating high precision and accuracy. Conclusion:This study confirmed the origin of fine particulate matter generated in Pohang through WSIIs analysis, and suggested that the measured electrical conductivity of WSIIs could be used as a key parameter for measuring the concentration of fine particulate matter.

Novel 3-(2-thienyl) acrylic acid bridge di-triphenyltin(IV) {[(Ph)3SnCl)2COO]-[Et3NH]+, [(Ph)3SnCl2)]-[Et3NH]+} complex: XRD/HSA-interactions, physicochemical, thermal and POM/antifungal evaluation

The coordination reaction of Ph3SnCl with (E)-3-(thiophen-2-yl)acrylic acid as simple –COOH acid ligand in (Et)3N medium leads to formation of {[(Ph)3SnCl)2COO]-[Et3NH]+,[(Ph)3SnCl2)]−[Et3NH]+} complex matrix in high yield for the first time. FT-IR, UV–Vis, EDX, and a single XRD were used to characterize the prepared complex. Moreover, the complex was crystallized in the triclinic system P-1 with [a = 12.5191(4); b = 13.5491(5); c = 21.9805(8); α = 100.2790(10); β = 99.1470 (10) and γ = 100.4390(10)] the lattice cell parameters. The resulting environment of each Sn(IV) centers are a distorted trigonal bipyramid geometry where the ligand carboxylate part connected both Sn(IV) centers via O,O-bi-chelate mode trans to the Cl anions, meanwhile, the thiophen part was not coordinated to Sn(IV) anymore. Moreover, only Cl…H H-bonds with nonclassical mononuclear and classical binuclear type of interactions were recorded. Computationally, the Cl…..H predominant interactions were confirmed by Hirschfeld Surface Analysis (HSA). TG of the complex was evaluated under open atmosphere. The complex’s antifungal activity against the pathogenic Fusarium oxysporum f.sp. albedins (FOA) showed more activity compared by the free ligand. Furthermore, POM theory was applied to evaluate the bioactivity and explain the experimental result of desired material against fungal.

Antioxidative 2D Bismuth Selenide via Halide Passivation for Enhanced Device Stability.

The topological insulator 2D Bi2Se3 is promising for electronic devices due to its unique electronic properties; however, it is challenging to prepare antioxidative nanosheets since Bi2Se3 is prone to oxidation. Surface passivation using ligand agents after Bi2Se3 exfoliation works well to protect the surface, but the process is time-consuming and technically challenging; a passivation agent that is stable under a highly biased potential is significant for in situ passivation of the Bi2Se3 surface. In this work, the roles of halide anions (Cl-, Br-, and I-) in respect of the chemical properties of synthetic Bi2Se3 nanosheets during electrochemical intercalated exfoliation were investigated to determine the antioxidation capacity. It was found that Bi2Se3 nanosheets prepared in a solution of tetrabutylammonium chloride (TBA+ and Cl-) have the best oxidation resistance via the surface bonding of Bi with Cl, which promotes obtaining better device stability. This work paves an avenue for adjusting the components of the electrolyte to further promote the stability of 2D Bi2Se3-nanosheet-based electronic devices.

Metal-Organic Framework Sub-Nanochannels Formed inside Solid-State Nanopore with Proton Ultra-High Selectivity.

Metal-Organic frameworks (MOFs) have the advantages of high porosity, angstrom-scale pore size, and unique structure. In this work, a kind of MOFs, UiO-66 and its derivatives (including aminated UiO-66-(NH2 )2 and sulfonated UiO-66-(NH-SAG)2 ), were constructed on the inner surface of solid-state nanopores for ultra-selective proton transport. UiO-66 and UiO-66-(NH2 )2 nanocrystal particles were in-situ grown at the orifice of glass nanopores firstly, which were used to investigate the ionic current responses in LiCl and HCl solutions when the monovalent anions (Cl- ) were unchanged. Compared with UiO-66-modifed nanopores, the aminated MOFs modification (UiO-66-(NH2 )2 ) can improve the proton selectivity obviously. However, when the UiO-66-(NH-SAG)2 nanopore is prepared by further post-modification with sulfo-acetic acid, lithium ions can hardly pass through the channel, and the interaction between protons and sulfonic acid groups can promote the transport of protons, thus achieving ultra-high selectivity to protons. This work provides a new way to achieve sub-nanochannels with high selectivity, which can widely be used in ion separation, sensing and energy conversion.

Unraveling the effects of zinc sulfate nanoparticles and potassium fertilizers on quality of maize and associated health risks in Cd contaminated soils under different moisture regimes

This study investigated the interactive effects of zinc sulfate nanoparticles (ZnSO4 NPs) and potassium fertilizers (SOP and MOP) on growth and quality of maize (Zea mays L.) under different moisture regimes in cadmium contaminated soils. It seeks to identify how these two different sources of nutrients interact to improve the quality of maize grains and fodder production to ensure food safety and food security under abiotic stresses. The experiment was conducted in a greenhouse under two moisture regimes including M1 (non-limiting regime, 20–30 %) and M2 (water-limiting, 10–15 %) at Cd contamination of 20 mg kg−1. The results showed that ZnSO4 NPs combined with potassium fertilizers significantly increased the growth and proximate composition of maize in Cd contaminated soil. Moreover, applied amendments significantly alleviated the stress induced in maize by improving the growth. The greatest increase in maize growth and quality was observed when ZnSO4 NPs were applied in combination with SOP (K2SO4). The results also showed that the interactive effects of ZnSO4 NPs and potassium fertilizers significantly affected the Cd bioavailability in soil and concentration in plants. It was observed that MOP (KCl) enhanced the Cd bioavailability in soil due to presence of Cl anion. In addition, the application of ZnSO4 NPs combined with SOP fertilizer reduced the concentration of Cd in maize grain and shoot, and significantly reduced the probable health risks to humans and cattle. It suggested that this strategy could help to reduce Cd exposure through food consumption and therefore ensure food safety. Our findings suggest that ZnSO4 NPs and SOP can be used synergistically to improve maize crop production and development of agricultural practices in areas affected by Cd contamination. Moreover, by understanding the interactive effects of these two sources of nutrients, this research could help in the management of areas affected by heavy metals contamination. Environmental implicationThe application of zinc and potassium fertilizers can increase the biomass of maize, minimize abiotic stresses, and improve the nutritional value of the crop in Cd contaminated soils; this is particularly true when zinc sulfate nanoparticles and sulfate of potash (K2SO4) are used in conjunction. This form of fertilizer management can lead to a greater, more sustainable yield of maize under contaminated soils, which could have a major impact on global food supply. Remediation coupled with agro-production (RCA) not only improves the effectiveness of the process but will also encourage farmers to take part in soil remediation by easy management.

Application of a Novel Bifunctionalized Magnetic Biochar to Remove Cr(VI) from Wastewater: Performance and Mechanism

Biochar adsorption has emerged as a favorable and environmentally friendly approach for removing metals such as chromium (Cr) from wastewater. However, the use of pristine biochar (PBC) is limited due to its finite adsorptive capacity, selectivity, and potential for secondary pollution. In this study, a novel bifunctionalized magnetic biochar (BMBC) was fabricated by incorporating cystamine as a ligand and glutaraldehyde as a crosslinker into alkali-treated magnetic biochar (MBC). This chemical modification introduced numerous amino groups and disulfide bonds onto the surfaces of BMBC. The biochar adsorbents’ surface morphologies, crystal structures, and texture properties were characterized using SEM, XRD, and N2 adsorption-desorption techniques. The specific surface area was determined using the BET method. Furthermore, the surface functional groups and elemental compositions before and after adsorption were analyzed using FTIR and XPS, respectively. The results demonstrated higher Cr(VI) removal efficacy of BMBC (100%) than MBC (72.37%) and PBC (61.42%). Optimal conditions for Cr(VI) removal were observed at a solution pH of 2, a temperature of 50 °C, a reaction time of around 1440 min, and an initial adsorbate concentration of 300 mg/L. The sorption process followed a chemical mechanism and was controlled by monolayer adsorption, with a maximum adsorption capacity of 66.10 mg/g at 50 °C and a pH of 2, as indicated by the larger fitting values of the pseudo–second-order and Langmuir models. The positive ∆Ho and ∆So values and negative ∆G0 values suggested a spontaneous and endothermic Cr(VI) adsorption process with high randomness at the solid/liquid interface. The removal of Cr(VI) was attributed to the reduction of Cr(VI) into Cr(III) facilitated by the introduced amino acids, sulfur, and Fe(II), electrostatic interaction between Cr(VI) in the solution and positive charges on the adsorbent surface, and complexation with functional groups. The presence of co-existing cations such as Cu(II), Cd(II), Mn(II), and K(I) had little effect on Cr(VI) removal efficiency. At the same time, the co-existence of anions of Cl−, NO3−, SO42−, and HPO42− resulted in a 7.58% decrease in the Cr(VI) removal rate. After five consecutive adsorption/desorption cycles, BMBC maintained a high Cr(VI) removal rate of 61.12%. Overall, this novel BMBC derived from rice straw shows great promise as a biosorbent for treating Cr(VI) in wastewater.

Standard operating procedure for the analysis of major ions in hydrothermal fluids by ion chromatography

This standard operating procedure (SOP) describes an ion chromatography (IC) procedure for the major cations and anions in hydrothermal fluids. Hydrothermal fluids are aqueous solutions with a wide range of temperature, salinity, pH and ion species that can be used by microbial metabolism as electron donors and electron acceptors. Due to the high variability of the environmental physical-chemical parameters in these samples, we have developed this protocol taking into account the special features of the matrices analyzed. An Eco IC Metrohm system equipped with a conductivity detector was used. Calibration curves are linear in the 0.1 to 10 mg/L concentration range for cations Ca2+, Na+, K+, Mg2+, NH4+ and anions Cl-, Br-, NO3-, NO2-, SO42- , HPO42- .

Selective and sensitive colorimetric sensing of iodine ions based on porous MoS2 particles with excellent haloperoxidase-like activity

Nanozymes continue to attract great interest due to their high enzyme activities, good biocompatibility, chemical stability and adjustable activity, which have been widely used in biosensing, disease therapy and antibacterial treatment. Herein we report porous MoS2 particles to have both excellent bromoperoxidase-like and iodoperoxidase-like activity. The MoS2 particles exhibited the highest Vmax value of 83 µM/s (H2O2 as substrate), remarkably superior to haloperoxidase and other haloperoxidase-like reported so far. The underlying mechanism of the iodoperoxidase mimics is oxygen vacancies. The iodoperoxidase-like can catalyze the oxidization of iodide ions (I−) by H2O2 to iodic acid (HIO3), which further enables to readily oxidize colorless 3,3’,5,5’-tetramethylbenzidine to green ox-TMB. Significantly, among the halogen anions (Cl−, Br− and I−), only I− was found to cause this oxidation reaction to occur. Thereafter, a fast, selective and cost-effective colorimetric detection of I− ion was developed with the linear range of 0.5–70 μM and detection limit of 292 nM (3σ/S). Further, the as-developed assay was applicable to detect seawater and human urines samples with satisfactory recoveries and accuracy. Thus the colorimetric assay based on MoS2 particles with haloperoxidase-like activity show great promise for I− sensing in environmental analysis and biochemical analysis.

The Effects of Ionic Liquid Addition on the Heat of Polymerization of Additive Manufacturing Resins

Ionic liquids (ILs) are utilized for a wide range of applications today due to their low vapor pressure, near infinite combination of cations and anions with varying chemical functionalities, organic and inorganic species solubility, as well as their superb thermal and chemical stabilities. In this work, four ILs are used as additives for 3D printing resins to add flexibility to the final printed parts. The ILs of interest are 1-n-butyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) and 2-(1-methylimidazolium)-ethyl methacrylate chloride ([mimEMA][Cl]), which were synthesized in-house, as well as tetraethylammonium bis(trifluoromethanesulfonyl)imide ([TEA][NTf2]) and Butyltrimethylammonium bis(trifluoromethanesulfonyl)imide ([BTMA][NTf2], which were purchased and used as received. These ILs were added to commercial Formlabs CV4 resin from 10 to 50 wt%. The change in temperature of polymerization is characterized via container-less acoustic levitation and FLIR thermography and the heat capacity is characterized with differential scanning calorimetry (DSC). From these two measurements, the enthalpy of polymerization was calculated via a simple equation relating the change in droplet temperature to the reaction enthalpy equation and compared to literature values. The degradation temperature of each was also characterized via thermal gravimetric analysis (TGA). Each IL lowered the enthalpy of polymerization while the substances with [NTf2] counterions raised the decomposition temperature and the only substance containing Cl anions, [mimEMA][Cl], lowered the decomposition temperature.

Probing the impact of alkyl chain length of imidazolium ionic liquids on the conformational stability of collagen type-I from skin of Lutjanus erythropterus

Multispectroscopic techniques and molecular docking study were carried out to inspect the role of concentrations and cationic chain length of ionic liquids (ILs), on the secondary structure of collagen type-I. To attain this objective, a series of imidazolium ILs having same anion (Cl−) and a set of cations with varying chain length were used in this study. The ILs studied utilized are 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]), 1-hexyl-3-methylimidazolium chloride ([Hmim][Cl]), and 1-decyl-3-methylimidazolium chloride ([Dmim][Cl]). The effect of these ILs on collagen type-I was analyzed by using UV-vis, circular dichroism (CD), steady state fluorescence, time resolve fluorescence (TRF), synchronous fluorescence, dynamic light scattering (DLS), fourier transform infrared spectroscopy (FT-IR) and molecular docking approach. The results obtained shows the stability of the collagen was dependent on the alkyl chain length of cation as well as concentration of these ILs. The alteration in hydrogen bonding and hydrophobic interactions due to the different cations of ILs, with the amino acid residues, play a key role in unfolding/destabilization of collagen. Consequently, the destabilization propensity of the ILs toward the collagen increases with increasing chain length of ILs. In addition, when organized in the order of providing destability to collagen triple helix structure, the cations of the ILs obeyed the Hofmeister series. Molecular docking also confirms more hydrophobic interaction and reduced hydrogen bonding due to long alkyl chain length of cations in ILs. The docking results are in agreement with the spectroscopic results and provide the information about the ligand binding site on the protein.

Mineral Assemblage of Olivine-Hosted Melt Inclusions in a Mantle Xenolith from the V. Grib Kimberlite Pipe: Direct Evidence for the Presence of an Alkali-Rich Carbonate Melt in the Mantle Beneath the Baltic Super-Craton

This report deals with the first mineralogical examination of secondary crystallized melt inclusions (CMIs) in healed cracks within olivine in a mantle peridotite xenolith from the V. Grib kimberlite pipe (Arkhangelsk diamondiferous province). In contrast to micro/nano-inclusions in diamonds, the studied CMIs are quite large (up to 50 µm), so that the mineral composition of the CMIs can be determined via conventional analytical approaches, e.g., Raman spectroscopy and scanning electron microscopy. Garnet peridotite is a coarse-grained mantle rock that equilibrates at 3.3 GPa and 750 °C (corresponding to a depth of ~100 km). The CMIs are therefore tiny snapshots of melt that existed in the shallow lithospheric mantle and were entrapped in olivine. In total, nineteen mineral species were identified among the daughter magmatic minerals of the CMIs. Various Na-K-Ca-, Na-Ca-, Na-Mg-, Ca-Mg-, Mg- and Ca-carbonates; Na-Mg-carbonates with the additional anions Cl−, SO42− and PO43−; alkali sulfates; chlorides; phosphates; sulfides; oxides; and silicates were established. Within the mineral assemblage, carbonates were predominant, with their abundance being more than 62 vol.%. The CMIs contained twelve alkali-rich minerals; nine of them were Na-bearing and showed bulk molar (Na + K)/Ca ≥ 1. The CMIs’ parental melt was an alkali-rich carbonate liquid that contained low amounts of SiO2 (≤9.6 wt%) and H2O (≤2.6 wt%). According to our estimates, the time of complete equilibration between olivine within the healed cracks and host olivine in the mantle at the calculated P-T parameters for the studied xenolith should be no more than several years. Based on this geologically short time span, a genetic link between the studied CMIs and the magmatism that formed the V. Grib kimberlite pipe is suggested.

Dicationic Diimine Pt(II) Bis(N-heterocyclic allenylidene) Complexes: Extended Pt···Pt Chains, NIR Phosphorescence, and Chromonics.

Although square-planar Pt(II) complexes are well-known to self-assemble into supramolecules via noncovalent intermolecular Pt···Pt and/or π-π interactions, the self-assembly of dicationic Pt(II) complexes was scarce due to the electrostatic repulsive force. Herein, a series of dicationic diimine bis(N-heterocyclic allenylidene) Pt(II) complexes were synthesized and characterized. Close Pt···Pt and/or π-π contacts are observed in the crystals of these complexes. In particular, complexes 1·2PF6 and 2·2PF6 exhibit one-dimensional packing with extended Pt···Pt contacts of 3.302 and 3.240 Å, respectively. The photophysical properties of these complexes in the solution and solid state were investigated. NIR emission was recorded for complexes 1·2PF6 (λmax = 950 nm) and 2·2PF6 (λmax = 855 nm) in the solid state at 298 K. To explore the aggregate behaviors of these complexes, the counteranion PF6- was exchanged to the large lipophilic anion 2,3,4-tris(dodecyloxy)benzene sulfonate (LA-) and the hydrophilic anion Cl-. Complexes 1·2LA and 2·2LA or 1·2Cl and 2·2Cl could self-assemble with Pt···Pt and/or π-π interactions in the nonpolar or aqueous solutions as well. Further increasing the concentration of 1·2Cl and 2·2Cl in aqueous solution, chromonic mesophases with NIR emission (λmax = 988 nm) were obtained. DFT and TD-DFT calculations were performed to gain deep insight into the dication-dication packings and photophysical properties of the complexes. The σ-donating as well as π-accepting character of the N-heterocyclic allenylidene ligand endows complexes with rigid and electron-delocalized coplanar features, which are conducive to achieving the self-assembling processes associated with Pt···Pt and/or π-π interactions.

Bridging Chloride Anions Enables Efficient and Stable InP Green Quantum‐Dot Light‐Emitting Diodes

AbstractZnMgO nanoparticles (NPs) are commonly used as the electron transport layer (ETL) in indium phosphide (InP) based quantum dots light‐emitting diodes (QLEDs). It has been experimentally found that the inherent oxygen vacancy defects in ZnMgO can be passivated by halogen additives. However, an in‐depth understanding of how the halogen additives in ZnMgO affect the quantum dots (QDs) films is currently missing. Here, the study reports on efficient and stable indium phosphide (InP) green QLEDs by effectively bridging QDs and ETL using chloride (Cl) ions. As bi‐functional anchoring additives, Cl ions not only passivate the oxygen vacancy defects of ZnMgO NPs for suppressing the exciton quenching at the QDs/ZnMgO interfaces, but also facilitate the hole transport of QDs due to part replacement of insulated oleic acid ligands on the surfaces of InP QDs with Cl anions for more balanced charge injection in the devices. Consequently, the optimized green InP QLED achieves a peak external quantum efficiency (EQE) of 13.8% and an operational lifetime of 5944 h, which, to the best of current knowledge, represents the best overall performance among the reported green InP QLEDs.

Selective Supramolecular Recognition of Nitroaromatics by a Fluorescent Metal–Organic Cage Based on a Pyridine-Decorated Dibenzodiaza-Crown Macrocyclic Co(II) Complex

Two isomorphous fluorescent (FL) lantern-shaped metal-organic cages 1 and 2 were prepared by coordination-directed self-assembly of Co(II) centers with a new aza-crown macrocyclic ligand bearing pyridine pendant arms (Lpy). The cage structures were determined using single-crystal X-ray diffraction analysis, thermogravimetric, elemental microanalysis, FT-IR spectroscopy, and powder X-ray diffraction. The crystal structures of 1 and 2 show that anions (Cl- in 1 and Br- in 2) are encapsulated within the cage cavity. 1 and 2 bear two coordinated water molecules that are directed inside the cages, surrounded by the eight pyridine rings at the "bottom" and the "roof" of the cage. These hydrogen bond donors, π systems, and the cationic nature of the cages enable 1 and 2 to encapsulate the anions. FL experiments revealed that 1 could detect nitroaromatic compounds by exhibiting selective and sensitive fluorescence quenching toward p-nitroaniline (PNA), recommending a limit of detection of 4.24 ppm. Moreover, the addition of 50 μL of PNA and o-nitrophenol to the ethanolic suspension of 1 led to a significant large FL red shift, namely, 87 and 24 nm, respectively, which were significantly higher than the corresponding values observed in the presence of other nitroaromatic compounds. The titration of the ethanolic suspension of 1, with various concentrations of PNA (>12 μM) demonstrated a concentration-dependent emission red shift. Hence, the efficient FL quenching of 1 was capable of distinguishing the dinitrobenzene isomers. Meanwhile, the observed red shift (10 nm) and quenching of this emission band under the influence of a trace amount of o- and p-nitrophenol isomers also showed that 1 could discriminate between o- and p-nitrophenol. Replacement of the chlorido with a bromido ligand in 1 generated cage 2 which was a more electron-donating cage than 1. The FL experiments showed that 2 was partially more sensitive and less selective toward NACs than 1.

Características hidroquímicas y ambiente acuático de las aguas superficiales y subterráneas poco profundas en el norte del delta del río Amarillo, China

The present study envisaged the dynamic monitoring and study of the hydrochemistry of the surface water and shallow groundwater in the northern part of the Yellow River Delta, China. Analysis of the surface water and shallow groundwater revealed that the shallow groundwater exhibited in two forms: precipitation evaporation type and hydrological type, and the latter was obviously affected by the dynamic water level of the Yellow River. The surface water and shallow groundwater exhibited a higher degree of mineralization. Cations of Mg2+, Na+ and K+ and anions of Cl- and SO42- were the main ion components of the total dissolved solids. The hydro-chemical type of shallow groundwater was Cl-Na·K that was a typical seawater or brine form. The water chemical type of surface water changed to Cl·SO4-Na·K·Ca due to the industrial, agricultural and urban pollution. The overall quality of surface water was poor, and the main pollution indexes were found to be present, except for cyanide. The levels of COD and fluorine exceeded the standard values in the surface water. The groundwater quality was poor, since most of the pollutants were detected, except for cyanide and volatile phenol. Eight indexes exceeded the groundwater quality standard levels including Cl-, Na+, total hardness, COD, NH4+, Hg, As, NO3-, Cl- and Na+. The pollution of the surface water and shallow groundwater was mainly caused by the discharge of the wastewater from the petroleum; chemical industry and brine enterprises; agricultural non-point source pollution; leakage of septic tanks and sewage pipes in urban and rural areas, and rainwater leaching from the garbage piles. In order to improve the water quality, the sewage control and management needs be optimised, and the industrial layout should be reconsidered.

Capillary suction under unsaturated condition drives strong specific affinity of ions at the surface of clay mineral

Mineral-solution interface is of great importance in many soil and geochemical processes as well as industrial applications. Most relevant studies were based on saturated condition and given the corresponding theory, model, and mechanism. However, soils are usually in the non-saturation with different capillary suction. Our study presents substantially different scenery for ions interacting with mineral surface under unsaturated condition using molecular dynamics method. Under partially hydrated state, both cations (Ca2+) and anions (Cl−) can be adsorbed as outer-sphere complexes at the montmorillonite surface, and the number significantly increased with the increase of unsaturated degree. Ions preferred to interact with clay mineral instead of water molecules under unsaturated state, and the mobility of both cations and anions substantially decreased with the increase of capillary suction as reflected by the diffusion coefficient analysis. Potential of mean force calculations further clearly revealed that the adsorption strength of both Ca2+ and Cl− increased with capillary suction. Such an increase was more obvious for Cl− compared to Ca2+, despite the adsorption strength of Cl− was much weaker than Ca2+ at a certain capillary suction. Therefore, it is the capillary suction under unsaturated condition that drives the strong specific affinity of ions at the surface of clay mineral, which was tightly related to the steric effect of confined water film, the destruction of EDL structure, and the cation-anion pair interaction. This suggests that our common understanding of mineral-solution interaction should be largely improved.

Photoelectrochemical Cerium Catalysis via Ligand-to-Metal Charge Transfer: A Rising Frontier in Sustainable Organic Synthesis

AbstractPhotoelectrochemical cerium catalysis is an emerging and rapidly developing strategy in organic synthetic. A sustainable platform is being constructed by combining the concerted energy transfer from light and electricity to cerium with the ligand-to-metal charge transfer of excited state CeIV species. With this powerful strategy, hard to oxidized substrates can be activated under mild conditions, contributing to broad functional group compatibility. Such as, carboxylic acids, alcohols, and the Cl anion can deliver the corresponding radicals via formal single electron transfer (SET) with a low oxidation potential. Further cooperation with other synthetic strategies, including alkoxy radical promoted hydrogen atom transfer (HAT) and β-scission, leads to the functionalization of inert C(sp 3)–H, Si–H, and C–C bonds via a mild radical pathway. In this review, recent advances in photoelectrochemical cerium catalysis are described. More importantly, as this field features some unique advantages, but is rarely explored, we hope chemists will pay more attention to this catalytic system.1 Introduction2 Activation of Carboxylic Acids3 Activation of Alcohols3.1 Alkoxy Radical Involved Hydrogen Atom Transfer3.2 Alkoxy Radical Promoted β-Scission4 Formal Single-Electron Oxidation of Cl Anion5 Conclusions and Outlook

Negative surface charge-mediated Fe Quantum dots with N-doped graphene/Ti3C2Tx MXene as chlorine-resistance electrocatalysts for high performance seawater-based Al-air batteries

Compared to conventional alkaline Aluminum-air (Al - air) batteries, seawater-based Al-air batteries are promising large-scale energy storage devices and are highly compatible with offshore ocean locations or large-scale maritime applications. However, the complexity of the seawater components, in particular, chlorine anions (Cl−) blocks the metal surface and hinders the oxygen reduction reaction (ORR) at the cathode. Herein, we employed plasma engineering to anchor Fe Quantum dots (QDs) on a negative charge-mediated surface composed of nitrogen-doped graphene (NG) and Ti3C2Tx MXene. The negative fluorine and hydroxyl groups on MXene and NG induced strong negative-charged surface with a build-in electric field to repel Cl−, effectively protected the Fe QDs active sites from the seawater electrolyte. As a result, the cathode electrocatalysts demonstrated high ORR catalytic activity in seawater electrolytes and achieved a high-power density output of 53.6 mW/cm2 and rate performance of 0.8 V at 50 mA/cm2 in Al-air seawater batteries.