Effect Of Anions Research Articles

(Invited) A Dive into the Complex Mechanisms That May or May Not Increase Li/Na Mobility in Solid State Conductors

The conductivity of Li and Na has achieved remarkably high values in some materials, higher than what has been achieved in liquid electrolytes. Because there is no mobile solvation shell in solid-state conductors, the maximum of conductivity is essentially unlimited. I will discuss our current understanding of the compositional and structural elements that contribute to very high alkali ion mobility. This will include a discussion, of activated complexes that create concerted motion, possible high-entropy effects, the effect of (poly)anions, and structural topology.

Anion-Driven Nanostructuring of Copper Electrodeposits for Tuning the Selectivity of Electrocatalytic CO2 Reduction Reaction

Electrochemical CO2 reduction (ECR) to value-added products is one of the potential ways to utilise CO2 as a feedstock, thereby decreasing its level in the atmosphere as it has harmful repercussions on planet earth. Copper (Cu)-nanostructures have demonstrated a great potential to convert CO2 into valuable higher-end hydrocarbons electrochemically, but with poor selectivity1. Therefore, novel strategies to tune Cu-based electrocatalysts' activity and selectivity toward multi-carbon products, particularly at low overpotential, are highly desirable. At the same time, keeping in mind the growing concerns regarding the environmental impact of the synthetic procedures and atom-economy among chemists, the synthesis methods employing reagents with multiple characteristics are equally essential to ensure minimal use of undesirable and excess reagents. In the present work, we report an atom-economic strategy to tune the physicochemical properties and the electrocatalytic activity of Cu-nanostructures towards ECR. The Cu-nanostructures namely CA, CN, CS and CC were synthesized via pulse electrodeposition from an electrolyte bath containing Cu-precursor salts with varying anions viz. acetate, nitrate, sulphate, and chloride respectively and are investigated for the effect of anions on the physicochemical properties and ECR performance. In the case of Cu electrodeposition process, when the pH is low as in the case of sulphate and acetate ions, electrodeposition is accompanied by hydrogen evolution reaction2 which results in the formation of nondendritic structures as in the case of CS and CA. But the presence of nitrate ions in the electrolyte bath causes nitrate reduction reaction to take place as a side reaction as well, as Cu is a well-known catalyst for nitrate reduction. Thus, this simultaneous redox reaction at the surface of the Cu electrodeposit causes an additional dissolution of the Cu nuclei3. This results in a smoother morphology as seen in CN as the dendrite formation is overridden. The very distinct cubic morphology of CC is due to Chloride ions in the bath.The presence of chloride ions during the electrodeposition of CC samples results in the formation of nanocubes by reducing Cu2+ via the formation of CuCl which is known to exist in cubic form when it precipitates4. The intermediate CuCl then quickly forms Cu2O through an equilibrium reaction in the presence of H2O when the concentration of chloride ions is not so high. The Cu-nanostructures electrodeposited from Cu-chloride demonstrated the best ECR performance with the highest total faradaic efficiency for carbon products and good selectivity for ethylene formation (30% at -0.93V vs RHE). The presence of chloride ions in the electrolyte bath strongly affects the active sites of the Cu deposits as the cubic morphology of CC catalyst exposes large number of Cu (100) faces5. Cu (100) are highly selective towards ethylene formation with very low overpotential due to the lower barrier for Cu-CO* which leads to greater CO coverage favouring CO*-CO* coupling at low bias59. In addition to that the electrochemically active surface area, the higher Cu+ content can be rationalized as the reasons for relatively higher ECR activity of CC.

Potassium Vanadium Fluorides as Positive Electrode Materials for K-Ion Batteries

Potassium-ion batteries (KIBs) have attracted much attention as a potential high-voltage and high-power secondary batteries due to a low standard electrode potential of K+/K in carbonate ester-based electrolytes and weak Lewis acidity of K+ (1). We reported the K+ ion extraction/insertion reactions in polyanionic compounds at a high average working potential of > 4 V vs. K+/K, which should be attributed to the inductive effect of anion(2)(3). However, the specific capacity of polyanionic compounds is often limited by the high mass of the redox-inactive polyanion framework. In this study, we focused on potassium-containing vanadium fluorides, which have high theoretical capacity.We first created a triangle phase diagram of K-V-F systems considering with their theoretical capacities, as shown in Fig. 1a. Based on the theoretical capacity and valence of V, K3VF6 was selected and synthesized, and its electrode behavior and structural changes associated with potassium extraction were investigated as a positive electrode material for KIBs.K3VF6 was synthesized through a mechanochemical method after mixing stoichiometric ratios of KF and VF3 with 10 wt% Ketjen black (KB) and calcined to enhance crystallinity. The calcination was performed in an argon atmosphere at 300 °C. The working electrodes were prepared by mixing the synthesized sample with conductive carbon (KB) and binder (PVdF) at a weight ratio of 8 : 1 : 1 and applying it to an Al foil. The charge-discharge tests were conducted using coin cells with the prepared positive electrode, K metal counter electrode, and 1.0 mol dm-3 KPF6/EC : PC = 1 : 1 (v/v) or 5.6 mol kg-1 KFSA/G3 electrolyte (4).The Rietveld refinement of the synchrotron XRD pattern of K3VF6 is shown in Figure 1b. All of the diffraction peaks, except for VO peaks, could be indexed to the tetragonal space group I4/m. The refinement showed good fitting with a low R wp value of 6.18 %. The diffusion barrier of K+ ions in K3VF6 was calculated to 0.77 and 0.89 eV along b-axis and c-axis, respectively, by the BVEL method.Figure 1c shows the initial charge/discharge curve of K3VF6 electrode. The electrode exhibited a plateau at about 3.7 V and an initial discharge capacity of about 95 mAh g-1, which corresponds to a one-electron reaction of V4+/3+ (Figure 1c).Figure 1d shows ex-situ XAFS measurements to investigate the variation of V valence state during charge/discharge. After being charged to 4.3 V, the white line peak shifted to the higher energy and the pre-edge peak became stronger than the pristine spectra, indicating oxidation of V from trivalent to tetravalent during charge. The white line and the pre-edge peaks of K3VF6 discharged to 2.0 V are almost identical to that of the pristine, showing reversible V3+/4+ redox. We will further discuss the structural changes during the K+ ion extraction/insertion process and the redox behavior of V in the presentation.

High Inhibition for a CoII Tetrazole Bi‐pyrazole Dinuclear Complex against Fusarium Oxysporum f. sp. Albedinis

AbstractNew coordination compounds made of two novel tetrazole and C,N‐bipyrazole ligands, 2‐(3,5,5′‐trimethyl‐1′H‐[1,3′‐bipyrazol]‐1′‐yl)acetonitrile (L1), and 1′‐((1H‐tetrazol‐5‐yl)methyl)‐3,5,5′‐trimethyl‐1′H‐1,3′‐bipyrazole (HL2), were prepared and fully characterized by spectroscopic techniques. Their crystal structures were identified by single‐crystal X‐ray diffraction revealing mononuclear complexes: [Ni(L1)3](ClO4)2 (1), [Cd(L1)2Cl2] (2), [Cu(HL2)(L2)]ClO4 (3), [Cu(L2)2] (4) and a dinuclear complex [Co2(HL2)(L2)Cl3] (5) comprising CoII ions in octahedral and tetrahedral surrounding within the same unit. Noticeably, 3 and 4 show different architectural structures due to ligand deprotonation as well as the effect of the counter anion. All compounds demonstrated antimicrobial activity against Gram (+) bacteria Listeria innocua and Staphylococcus aureus, as well as Gram (−) bacteria such as Escherichia coli and Pseudomonas aeruginosa, and antifungal activity against pathogenic fungi Geotrichum candidum, Aspergillus niger, and Penicillium crustosum. Interestingly, a high inhibition activity of 97 % was reached for 5 with a low concentration of only 81.1 μmol/L against Fusarium oxysporum f. sp. Albedinis, which is commonly damaging palm trees crops.

Solvent-Modulated Specific Ion Effects: Poly(N-isopropylacrylamide) Brushes in Nonaqueous Electrolytes.

Pertinent to cryopreservation as well as energy storage and batteries, nonaqueous electrolytes and their mixtures with water were investigated. In particular, specific ion-induced effects on the modulation of a poly(N-isopropylacrylamide) (PNIPAM) brush were investigated in various dimethyl sulfoxide (DMSO)-water solvent mixtures. Spectroscopic ellipsometry and neutron reflectometry were employed to probe changes in brush swelling and structure, respectively. In water-rich solvents (i.e., pure water and 6 mol % DMSO), PNIPAM undergoes a swollen to collapsed thermotransition with increasing temperature, whereby a forward Hofmeister series was noted; K+ and Li+ electrolytes composed of SCN- and I- salted-in (stabilized) PNIPAM chains, and electrolytes of Cl- and Br- salted-out (destabilized) the polymer. The cation was seen to play a lesser role than that of the anion, merely modulating the magnitude of the anion effect. In 70 mol % DMSO, a collapsed to swollen thermotransition was noted for PNIPAM. Here, concentration-dependent specific ion effects were observed; a forward series was observed in 0.2 mol % electrolytes, whereas increasing the electrolyte concentration to 0.9 mol % led to a series reversal. While no thermotransition was observed in pure DMSO, a solvent-induced specific ion series reversal was noted; SCN- destabilized the brush and Cl- stabilized the brush. Both series reversals are attributed to the delicate balance of interactions between the solvent, solute (ion), and substrate (brush). Namely, the stability of the solvent clusters was hypothesized to drive polymer solvation.

Visible Light-Assisted Degradation of Sulfamethoxazole on 2D/0D Sulfur-Doped Bi2O3/MnO2 Z-Scheme Heterojunction Immobilized Photocatalysts.

Retrieving the spent photocatalysts from the reaction system is always a challenging task. Therefore, the present work is focused on immobilizing sulfur-doped-Bi2O3/MnO2 (S-BOMO) heterojunction photocatalysts over different support matrices and evaluating their performance for the removal of sulfamethoxazole (SMX) in water under visible light. Our findings revealed S-BOMO coated clay beads (S-BOMO CCB) achieving more than 86% (240 min) SMX degradation ∼3, ∼1.3, and ∼2 times higher compared to S-BOMO coated on the different substrates, including glass beads, floating stones, and polymer material substrates, respectively. Mott-Schottky measurements confirmed the construction of the Z-scheme heterojunction involving MnO2 and 2S-Bi2O3. This Z-scheme mechanism, along with its narrow band gap of 1.58 eV, resulted in a rapid spatial transfer of the photogenerated charge carriers between the semiconductors and is believed to enhance the overall photocatalytic activity of the nanocomposite. Radical trapping and electron paramagnetic resonance results clearly established the active role of hydroxyl radicals and hydrogen peroxide in the degradation of SMX. Further, the 2S-BOMO CCB demonstrated excellent stability and photocatalytic activity over multiple runs. According to the sensitivity analysis and the results of anion effect experiments, phosphate and sulfate ions exhibit a significant impact on sulfamethoxazole degradation. Toxicity analysis revealed that 2S-BOMO CCB and sulfamethoxazole degradation byproducts were apparently innocuous. Additionally, the practical applicability of 2S-BOMO CCB was examined in various real water matrices, with the degradation efficiency followed the order: tap water < groundwater < surface water < hospital wastewater < municipal wastewater < pharmaceutical industry wastewater. The economic assessment revealed the reduction in the overall cost of the immobilized 2S-BOMO following the recovery process. Overall, the findings of this work provided critical insights into the synthesis and performance of incredibly effective and stable immobilized photocatalysts for the degradation of pharmaceutical pollutants.

Effect of Anions on the Delithiation of [Li–Al] Layered Double Hydroxides: Thermodynamic Insights

Effect of Anions on the Delithiation of [Li–Al] Layered Double Hydroxides: Thermodynamic Insights

Sulfidation of nano zero-valent iron for enhanced hexavalent chromium removal performance

Nano zero-valent iron (nZVI) and sulfidation-modified nZVI (S-nZVI) were synthesized and used to remove hexavalent chromium (Cr(VI)) in wastewater. Characterization of the products showed that the sulfidation process significantly changed the morphology of nZVI, with enhanced crystallinity. The effects of S/Fe ratio, pH value, and reaction temperature on Cr(VI) removal were studied. A S/Fe ratio of 0.5 was the most appropriate parameter, with a removal efficiency of 98% in the condition of pH = 2. The effects of anions (Cl−, NO3−, CO32−, and SO42−) and cations (Ca2+ and Mg2+) on the Cr(VI) removal efficiency were investigated, and the relevant mechanisms were discussed. The Cr(VI) removal efficiency of S-nZVI was significantly greater than that of nZVI, mainly owing to the existence of FeS layers that could protect Fe0 cores and prompt electron transfer. The aging and cycling experiments showed that S-nZVI could maintain its reactivity when facing the corrosion of water, and showed cycling stability. Thus, S-nZVI is an effective and feasible agent for the remediation of Cr(VI)-contained wastewater.

Removal of Malachite Green by Poly(acrylamide-co-acrylic acid) Hydrogels: Analysis of Coulombic and Hydrogen Bond Donor-Acceptor Interactions.

Water pollution caused by dyes poses a significant threat to life on earth. Poly(acrylamide-co-acrylic acid) hydrogels are widely used to treat wastewater from various pollutants. This study aims to examine the removal of malachite green (MG), a harmful and persistent dye that could cause extensive environmental damage, from an aqueous solution by adjusting the initial concentration of acrylamide (AM) and the degree of copolymer crosslinking. The copolymer hydrogels efficiently eliminate MG in a brief timeframe. The most successful hydrogel accomplished a removal rate exceeding 96%. The copolymer of 4 wt % 1,6-hexanediol diacrylate and a concentration of 100 mg/mL AM was effective. The degree of swelling was affected by crosslinking density as expected, with low crosslinking ratios resulting in significant swelling and high ratios resulting in less swelling. To evaluate the results, a docking approach was used which presented three crosslinked models: low, medium, and high. The copolymer-dye hydrogel system displayed robust hydrogen bonding interactions, as confirmed by the high quantities of both donors and acceptors. It was determined that MG contains six rotatable bonds, enabling it to adapt and interact with the copolymer chains. The dye and copolymer enhance H-bond formation by providing two hydrogen bond donors and 16 hydrogen bond acceptors, respectively. Through capitalizing on cationic and anionic effects, the ionic MG/copolymer hydrogel system improves retention efficiency by enhancing attraction between opposing charges. It is interesting to note that the synthesized copolymer is able to remove 96.4% of MG from aqueous media within one hour of contact time.

Anion effect on absorption and photovoltaic efficiency of some complex iodobismuthates

The photovoltaic use of iodoplumbates perovskites is limited because of lead toxicity and its instability. An alternative is the iodobismuthate compounds. In this work, the microscopically optical properties of two iodobismuthate compounds, (C28H40N4)(Bi4I18) and (C6H8N)(BiI5), are obtained using first principles. To relate these properties to the structure and to analyze the effect of the iodine linker atoms in these compounds, we split the absorption coefficients into an exact many-specie expansion. The results indicate that the optical gap and the optical properties are determined by the anionic fragment of these compounds. The presence of iodine linker atoms results in a reduction in the energy gap and a larger absorption near the gap.

Effect and mechanism of inorganic anions on the adsorption of Cd2+ on two-dimensional copper-based metal–organic framework

Metal-organic frameworks exhibit strong adsorption performance for Cd2+ in wastewater due to their multi-level pores and easily modified structure. In this paper, a copper based metal–organic framework: [Cu·(HL)·(DMF)]n (1) (H3L = 5-hydroxy isophthalic acid; DMF = N,N-dimethylformamide), was synthesized by hydrothermal synthesis method. The structural analysis shows that each Cu(II) in 1 is coordinated with four carboxylate O atoms from HL2− and one O atom from DMF. The two carboxylate groups in HL2− take μ2-η1:η1 to bridge two Cu(II) ions formed a two-dimensional structure. The scanning electron microscope (SEM) analysis shows that the nanomaterials prepared by the crushing method have dendritic structures and particle diameters of approximately 100 nm. The experimental results of the nano adsorbent adsorbing Cd2+ show that at an isoelectric point pH = 6, the optimal adsorbent concentration is 0.20 g/L. The maximum adsorption capacity at this time is 75.22 mg/g, which is superior to most MOFs adsorbents. At this optimal adsorbent concentration, as the solution pH increases, the adsorption capacity of the adsorbent for Cd2+ significantly increases. The thermodynamic analysis results of adsorption show that the △G < 0 and △H < 0 of the adsorbent in the range of 20–40 ℃, indicating that the adsorption of Cd2+ by the adsorbent is a spontaneous and exothermic process. The inorganic anions Cl−, HCO3−, NO3−, SO42− inhibit the adsorption of Cd2+ by nano adsorbent at a pH of 6. However, at low pH values (4, 5), it promotes the adsorption of Cd2+. This is mainly because the presence of inorganic anions changes the form of Cd2+ in solution, affecting the adsorption of it by the adsorbent.

Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution

Natural limonite, which contains mainly nano-sized iron and manganese oxides, is widely distributed worldwide. This study investigated the kinetics, thermodynamics, and the effects of pH, ion strength, and anions on the adsorption of Sb(III) via limonites sampled from Xinqiao and Yeshan (Tongling, China). Results show that adsorption equilibrium is achieved after 24 h for all experiments. Under initial Sb(III) = 200 mg/L, pH = 3.0, and temperature = 25 °C, Sb adsorption quantities for X1 (Mn-free limonite from Xinqiao), X2 (Mn-containing limonite from Xinqiao), Y1 (Mn-free limonite from Yeshan), and Y2 (Mn-containing limonite from Yeshan) are 10.92, 12.97, 27.12, and 89.34 mg/g, respectively. Manganese oxides in limonites promote Sb removal through oxidizing Sb(III) to Sb(V). The adsorption processes for all four limonites are fitted with a pseudo-second-order model. All adsorptions except for X1 fit with the Freundlich model; for X1, the Langmuir adsorption model is better. All adsorptions are spontaneous reactions (ΔG &lt; 0). All adsorptions except for Y1 (ΔH &lt; 0, exothermic reaction) are endothermic reactions (ΔH &gt; 0). Antimony adsorption is independent of solution pH for Mn-free limonites but is negatively related to solution pH for Mn-containing limonites. Generally, ion strength has a weak positive effect on Sb adsorption. The effects of anions on Sb adsorption are grouped into three types: weak negative (NO3− and SO42−), negative (CO32−, SiO44−, and PO43−), and equivocal (humic acid). This study indicates that due to a much higher surface area, Yeshan (124.8 m2/g for X1 and 171.7 m2/g for X2) rather than Xinqiao (13.7 m2/g for Y1 and 12.8 m2/g for Y2) limonites are better materials for Sb(III) removal in an aqueous solution. The key factors for the better use of limonite as an Sb(III) treatment material include temperature, pH, ion strength, and Mn content.

Synthesis of temperature-sensitive ion-imprinted polymer based on chitosan for selective separation of La3+ from aqueous solution: Effect of different salt anions in the template

Temperature-sensitive chitosan-based ion-imprinted polymer (TCIIP) is a promising adsorption material due to its ability to recycle only by rinsing with cold deionized water. However, little attention has been paid to the role of salt anions in the template. Herein, lanthanum ion-imprinted polymers ([La3+-anions]-CS-IIPs) were synthesized using different lanthanum salts containing anions (NO3-, Cl- and CH3COO-) as template, CS and NIPIM as functional monomer, BIS as crosslinker, APS as initiator. The adsorption performance of La3+ in aqueous solution on the [La3+-anions]-CS-IIPs have been studied. SEM, BET, XPS and FTIR were performed to characterize the synthesized materials. The results showed that the disparities in adsorption capacity and selectivity of the three [La3+-anions]-CS-IIPs could be attributed to the template effect and various affinities for rare earth ions, arising from salt anions with different geometric shapes, ionic radii and rare earth ion complexing capacities. The adsorption capacity of these [La3+-anions]-CS-IIPs is [La3+-NO3-]-CS-IIPs > [La3+-CH3COO-]-CS-IIPs > [La3+-Cl-]-CS-IIPs. Three kinetic and isothermal adsorption models in each were used to investigate the adsorption mechanism of La3+ on [La3+-anion]-CS-IIPs. The adsorption capability of three [La3+-anions]-CS-IIPs retained above 92% in the 4 times adsorption-desorption process. Meanwhile, three [La3+-anions]-CS-IIPs clearly have higher adsorption affinities for La3+ than Ce3+, Nd3+, Y3+. The adsorption selectivity of [La3+-anions]-CS-IIPs is [La3+-CH3COO-]-CS-IIP > [La3+-Cl-]-CS-IIP > [La3+-NO3-]-CS-IIP. The findings of this work provide an idea for regulating the selective adsorption behavior of rare earth ion imprinted polymers by utilizing the anions effect.

Electrochemically exfoliated graphene-graphite architecture with MnO2 for redox pseudocapacitive process

An electrochemical exfoliation-deposition strategy is provided to fabricate the MnO2-based electrode. After the efficient exfoliation in MnSO4 electrolyte, the stacked graphite expands into open structure, with vertical graphene sheets strongly bonded on the surface. This unique architecture not only provides sufficient surface areas for the anchoring of oxygen vacancy-enriched MnO2, but also ensures transportation pathways for the charge transfer and electrolyte ions diffusion. Thus, the resultant electrode exhibits an areal specific capacitance of 447.5 mF cm−2 at 0.5 mA cm−2 and promising cycling stability. It outperforms the analogues exfoliated in another Mn-based electrolyte because of the anion effect. In situ Raman spectra are taken to reveal the structural evolutions of the resultant electrode coupled with Na+ ions insertion-extraction behaviors in the redox pseudocapacitive process.

Insights on the Anion Effect in N-heterocyclic Carbene Based Dinuclear Gold(I) Catalysts.

Dinuclear bisNHC (bis(N-heterocyclic carbene)) gold(I) complexes 3 a and 4 a of general formula [Au2 Br2 (bisNHC)] were tested as catalysts in the cycloisomerization of N-(prop-2-yn-1-yl)benzamide and in the hydromethoxylation of 3-hexyne in the presence of silver(I) activators bearing different counteranions. The catalytic performance of mononuclear NHC complexes (1 a, 2 a) in the same reactions was also studied. The results highlighted the fundamental role of both NHC ligand and counterion in the catalytic cycles and activation process: dinuclear catalysts exhibit higher initial activity even under milder conditions but suffer in terms of stability with respect to mono NHCs. Furthermore, a new dinuclear bisNHC gold(I) complex 4 b of general formula [Au2 (OTs)2 (bisNHC)] (OTs=p-toluenesulfonate) was successfully synthesized and characterized by means of NMR and ESI-MS analyses.

Anion effect on oxygen reduction reaction activity of nitrogen doped carbon nanotube encapsulated cobalt nanoparticles

In this work, we report the diverse cobalt precursors for the synthesis of nitrogen doped carbon nanotubes encapsulated Co nanoparticles (Co@NCNT) as oxygen reduction reaction (ORR) electrocatalyst to verify the anion effect. The X-ray photoelectron spectroscopy (XPS) test indicates that more pyridinic and pyrrolic N species coordinate with Co atoms for cobalt chloride (CoCl2) due to more defective sites on NCNT etched by chlorine compared to the counterparts of cobalt nitrate (Co(NO3)2), cobalt acetate (Co(Ac)2) and cobalt triacetoacetate (Co(acac)2). With higher content of Co–Npyridinic+pyrrolic structures, Co@NCNT-Cl exhibits a robust ORR performance highlighted by half-wave potential of 880 mV vs. RHE, corresponding to a 4-fold better kinetic current density than commercial Pt/C. The superior catalytic activity toward ORR originates from more Co–Npyridinic+pyrrolic structures efficiently hydrogenated the adsorbed O2 to *OOH intermediate; additionally, its low binding strength with *OOH allows the mobility to metallic Co for splitting to generate O* species. Thus, a relay ORR catalysis is noticed for Co@NCNT-Cl. The assembled rechargeable zinc-air battery (ZAB) reaches a power density of 152 mW cm−2 sustained for 500 h, superior to Pt/C-IrO2. Moreover, the all-solid-state ZAB delivers a maximum power density of 54 mW cm−2 and maintains for 30 h.

The effect of Hofmeister series anions on the critical overlap concentration of soybean isolate protein

The influence of different concentrations of Hofmeister series anions on the critical overlap concentration (c*) of soybean isolate protein (SPI) was investigated, along with its potential mechanisms. Techniques including SDS-PAGE electrophoresis, endogenous and exogenous fluorescence spectroscopy, circular dichroism spectrum, Fourier infrared spectroscopy, and solubility analyses were employed. Results demonstrated that higher concentrations of various anions within the solution had an impact on the protein's secondary structure, in line with the principles of the Hofmeister series. This led to a decline in the α-helix proportion and a concomitant increase in the ratio of β-sheets and random coils. Consequently, the protein's structural integrity was compromised, revealing more hydrophobic groups. This alteration in turn affected protein solubility, ultimately influencing the c* of SPI. Furthermore, analysis of scanning electron microscopy images indicated that the introduction of anions indeed influenced the degree of aggregation and the visual characteristics of SPI, with this aggregation trend closely mirroring that of the Hofmeister series anions. In conclusion, the Hofmeister series anions were found to modulate the c* of SPI by inducing changes in the protein's structural arrangement and functional properties.

Anion Effect on Charged AIEgens‐Based Aggregates

AbstractCharged aggregation‐induced emission luminogens (AIEgens) are highly valued materials with attractive applications. However, the discussion of charged AIEgens with the characteristics of charged compounds is always centered around the cationic luminescence part, and the possible influence brought by anion effects is usually ignored especially in the field of aggregate science. Coupled with the complicated synthesis and purification processes of the brand‐new cationic nucleus, it is paramount to develop simpler and more feasible methods to enhance cognition and extend their performance. Herein, three new ionic compounds based on TPE‐IQ‐2TPA (TI2T) cationic core utilizing an anion substitution strategy are investigated. Interestingly, this strategy can modify molecular aggregation behavior regarding the photophysical process and arrangement of the molecules. Consequently, fluorescence emission, reactive oxygen species (ROS) generation ability, and mechanochromism response properties varied accordingly. Moreover, this strategic regulation of the physical parameters of self‐assembled nanoparticles facilitates the visual identification of living or dead cells, while also selectively illuminating S. aureus and C. albicans. This study demonstrates that anion engineering is a powerful tool for investigating aggregated states and provides a new platform for practical applications of advanced materials, especially in the fields of stimulus‐response, biological imaging, medical diagnosis, and treatment.

The effect of different anions on the crystallization course of α‐Al2O3 powder in hydrothermal method

Abstractα‐Al2O3 powder with excellent sintering properties plays an irreplaceable role in advanced ceramics. However, the preparation of α‐Al2O3 at low temperature still remains a grand challenge. Herein, aluminum sulfate, aluminum nitrate, and aluminum chloride are used as raw materials for α‐Al2O3 synthesis. In general, the Al3+ will be hydrolyzed to form AlOOH during the hydrothermal process. But SO42− reacted with Al3+ and OH− to form Al4(OH)10SO4 during the hydrothermal process. During the calcining process, the transition temperatures from AlOOH to α‐Al2O3 were 1100°C, which can be summarized as follows: AlOOH → γ‐Al2O3 → θ‐Al2O3 → α‐Al2O3. Meanwhile, Al4(OH)10SO4 converted into pure α‐Al2O3 at only 1050°C, due to the direct conversion from γ‐Al2O3 to α‐Al2O3. This spherical α‐Al2O3 was made up by completely uniformed small particles of about 10–20 nm. Finally, an Al2O3 ceramic with 98.07% of theoretical density and .01% water absorption rate was obtained at a temperature of 1600°C. This work offers an intriguing solution toward the development of Al2O3‐based advanced ceramics.

Simple anion-modified layered double oxides use for controlling Cu valence states for low-temperature CO-SCR

The modification of transition metal catalysts for selective catalytic reduction of NO by CO has been studied extensively. However, the effect of anion on CO-SCR catalyst modification is rarely reported. In this study, four different LDHs precursors were synthesized by using urea hydrothermal method and introducing different inorganic anions into the reaction system to control the self-assembly growth during the synthesis of LDHs. It is then loaded with a mass ratio of 7.5 % copper by impregnation method. The LDO(N)/Cu7.5 catalyst using nitrate ions regulated LDH as support achieved a high NO conversion of 96 % at 150 °C, which outdistanced the LDO(S)/Cu7.5 with support regulated by sulfate ions. A series of characterizations demonstrated that CoFe-LDH modified with different anions could modulate the valence state of loaded copper species. Among them, the LDO(N)/Cu7.5 catalyst was able to produce more Cu+ as the active site for the catalytic reaction. In situ DRIFTS further revealed the reaction mechanism, following the E-R mechanism at ≤150 °C and the L-H mechanism at 200–350 °C. This work supplies a new idea for the valence modulation of copper and the modification of LDH materials for applications in CO-SCR.