Ion Modification Research Articles

Controllable Electrodeposition Adjusts the Electrochromic Properties of Co and Mo Co-Modified WO3 Films

Metal ion modification is considered to be an effective way to construct metal oxides with specific physical and chemical properties. In this paper, we prepare a tungsten oxide (WO3) film co-modified by Co-ion and Mo-ion to serve as the electrochromic material through a one-step electrodeposition method. The effect of electrodeposition time on film thickness, surface morphology and electrochromic properties is systematically studied as well. The results show that, compared with pure WO3 film, the surface morphology of the tungsten oxide film modified by Co-ion and Mo-ion (WO3: Co, Mo) is significantly different. The Co and Mo co-modified film possesses a higher transmission modulation (58.5% at 600 nm) and rapid switching speed (coloring and bleaching time are 2.7 s and 5.6 s, respectively), low impedance value and excellent cycle stability. The performance enhancement is mainly attributed to the coral-like structure of the membrane, which provides a larger specific surface area, more ion adsorption sites and faster ion diffusion. Therefore, this work provides a fast and low-cost method to prepare tungsten oxide electrochromic films co-modified with cobalt and molybdenum ions. At the same time, it also provides an idea to obtain films with different electrochromic properties by adjusting the film thickness.

Graphene Quantum Dots Via Ion Modification for Improving Photoluminescence Stability in Aqueous Solution with Heavy Metal Ions

Graphene Quantum Dots Via Ion Modification for Improving Photoluminescence Stability in Aqueous Solution with Heavy Metal Ions

Lanthanum Ion Modification of Aminated Cyclomatrix Polyphosphazene-Coated Porous Carbon Nanosheets for Rapid, Efficient and Selective Removal of Phosphate

Lanthanum Ion Modification of Aminated Cyclomatrix Polyphosphazene-Coated Porous Carbon Nanosheets for Rapid, Efficient and Selective Removal of Phosphate

Simulation of initial stage of silicon cluster formation during post-annealing of memristive structures based on silicon oxide films subjected to Si+ implantation

The evolution of the SiO1.7 film defect structure caused by Si+ ion implantation and post-annealing at 1500K for 100 ns has been simulated by using two methods: Monte-Carlo and molecular dynamics. Clustering of silicon atoms and change of the near-structure close order are detected for the selected ion dose of 1·1017 cm-2. The results are discussed in relation to the problem of ion modification of silicon-oxide-based memristors and microscopic mechanisms of electroforming and resistive switching.

Toward understanded the electrochemical capacitance mechanism of MXene by intercalation of inorganic ions and organic macromolecular ions

Interlayer ion modification of MXene is one of the effective ways to improve the pseudocapacitance performance. However, the origin of electrochemical capacitance mechanism still remains elusive due to the effect of different kinds of ion interlayer modification. In this work, interlayer modification of MXene (Ti3C2Cl2) with inorganic ions (NaCl) and organic macromolecular ions (cetyl trimethyl ammonium bromide cation, CTAB) were carried out by ion ultrasonic intercalation and the electrochemical capacitance mechanism was investigated. It was found that MXene- CTAB has higher specific capacitance (258.28F g−1 Vs 225.55F g−1) and better cycle stability (93% retention Vs 85% retention after 3000 cycles) than MXene-NaCl. Such a large difference in electrochemical energy storage performance is mainly due to two points : (1) Organic macromolecular CTAB can effectively expand the layer spacing of MXene, which is conducive to the storage of electrolyte ions. (2) Compared with inorganic ions, organic macromolecular ions not only have redox reaction with interlayer ions of MXene, but also can adsorb counter ions in the electrolyte, thus providing additional pseudocapacitance. This work opens up a new way for the development of high-performance MXene based electrode materials.

Effect of Fluoride Ion on the Separation of Fluorite from Calcite Using Flotation with Acidified Water Glass

As a common depressant, acidified water glass (AWG) has strong inhibitory effects on fluorite and calcite. The inhibited fluorite is difficult to be recovered, thus resulting in the waste of resources and low flotation efficiency. In this study, the interaction of fluoride ions with fluorite and calcite surfaces was investigated, and its effects of AWG adsorption on mineral surfaces were evaluated. Micro-flotation experiments indicated that the flotation recovery of fluorite is 88.72% after fluoride ion treatment, that is, approximately fourfold with respect to that without fluoride ion modification. The results of solution chemical calculations showed that SiO(OH)3− is the main component to inhibit fluorite, and Si(OH)4 is the main component to inhibit calcite in AWG solution. XPS and ICP-MS results showed that fluoride ions can improve the floatability of fluorite by converting CaSiO3 on the surface of fluorite into CaF2, but the conversion ability of Si(OH)4 on the surface of calcite is weak, which increases the difference in floatability between fluorite and calcite. The above results were further verified by the analysis of flotation foam image and contact angle measurement. After fluorine ion treatment, the contact angle of fluorite increased, and it was more easily adsorbed on the foam. Therefore, the interaction of the fluoride ion with the fluorite surfaces eliminated the adsorption of AWG on fluorite, thereby resulting in the enhanced hydrophobicity of fluorite. Different from the traditional metal ions modification, the idea of anion modification in this paper is expected to be further studied.

Controllable release ratiometric fluorescent sensor for hyaluronidase via the combination of Cu2+-Fe-N-C nanozymes and degradable intelligent hydrogel

As a popular controllable-released carrier, intelligent hydrogels are often used in drug delivery and disease therapeutics. Meanwhile, benefit from the mimic-enzyme activity performance, Fe–N–C nanozymes have been widely used in sensing and analysis. However, the combination of intelligent hydrogels with specific degradability and Fe–N–C nanozymes with enhanced activity in one system to achieve controllable and sensitive detection is rare. Herein, we combine intelligent hydrogel with mimic peroxidase activity enhanced Fe–N–C nanozymes to construct a ratiometric fluorescence probe for sensitive detection of hyaluronidase (HAase). The modification of copper ions has been proved to enhance the mimic enzyme activity of Fe–N–C nanozymes greatly. Cu2+ modified Fe–N–C nanozymes were embedded in hyaluronic acid hydrogel. In the presence of HAase, the HA hydrogel structure was hydrolyzed and released Cu2+-Fe-N-C nanozymes gradually. The released Cu2+-Fe-N-C nanozymes are used to catalyze the hydrogen peroxide system so that o-phenylenediamine is oxidized to orange fluorescent 2, 3-diaminophenolazine (DAP). Due to the electrostatic interaction, the fluorescence resonance energy transfer can occur between the negatively charged copper nanoclusters emitted by 430 nm and the positively charged DAP emitted by 560 nm. The activity of HAase was monitored according to the ratio of fluorescence intensity at 560 nm and 430 nm (F560/F430). The linear range of this method is 0–10.0 U/ml and the detection limit is 0.43 U/mL (S/N = 3). This strategy has been further applied to biological samples successfully.

Copper-Containing Nanoparticles and Organic Complexes: Metal Reduction Triggers Rapid Cell Death via Oxidative Burst.

Copper-containing agents are promising antitumor pharmaceuticals due to the ability of the metal ion to react with biomolecules. In the current study, we demonstrate that inorganic Cu2+ in the form of oxide nanoparticles (NPs) or salts, as well as Cu ions in the context of organic complexes (oxidation states +1, +1.5 and +2), acquire significant cytotoxic potency (2–3 orders of magnitude determined by IC50 values) in combinations with N-acetylcysteine (NAC), cysteine, or ascorbate. In contrast, other divalent cations (Zn, Fe, Mo, and Co) evoked no cytotoxicity with these combinations. CuO NPs (0.1–1 µg/mL) together with 1 mM NAC triggered the formation of reactive oxygen species (ROS) within 2–6 h concomitantly with perturbation of the plasma membrane and caspase-independent cell death. Furthermore, NAC potently sensitized HCT116 colon carcinoma cells to Cu–organic complexes in which the metal ion coordinated with 5-(2-pyridylmethylene)-2-methylthio-imidazol-4-one or was present in the coordination sphere of the porphyrin macrocycle. The sensitization effect was detectable in a panel of mammalian tumor cell lines including the sublines with the determinants of chemotherapeutic drug resistance. The components of the combination were non-toxic if added separately. Electrochemical studies revealed that Cu cations underwent a stepwise reduction in the presence of NAC or ascorbate. This mechanism explains differential efficacy of individual Cu–organic compounds in cell sensitization depending on the availability of Cu ions for reduction. In the presence of oxygen, Cu+1 complexes can generate a superoxide anion in a Fenton-like reaction Cu+1L + O2 → O2−. + Cu+2L, where L is the organic ligand. Studies on artificial lipid membranes showed that NAC interacted with negatively charged phospholipids, an effect that can facilitate the penetration of CuO NPs across the membranes. Thus, electrochemical modification of Cu ions and subsequent ROS generation, as well as direct interaction with membranes, represent the mechanisms of irreversible membrane damage and cell death in response to metal reduction in inorganic and organic Cu-containing compounds.

Multiple Anti-Counterfeiting and optical storage of reversible dual-mode luminescence modification in photochromic CaWO4: Yb3+, Er3+, Bi3+ phosphor

Luminescence modification of rare earth ions doped phosphors based on photochromism is beneficial to expand their practical applications. Here, Bi3+ co-doping CaWO4: Yb3+, Er3+ phosphor is prepared. Color of CaWO4: Yb3+, Er3+, Bi3+ phosphor turn black grey upon the 254 nm ultraviolet light irradiation due to Bi3+ co-doping induced formation of the defects. Black grey CaWO4: Yb3+, Er3+, Bi3+ phosphor can recover their color to the primitive state under the stimulation of 473 or 532 nm lasers, exhibiting the double-light induced reversible photochromism. Dual-mode upconversion and downshift luminescence of CaWO4: Yb3+, Er3+, Bi3+ phosphor is reversibly modified based on its photochromism property. Potential applications of CaWO4: Yb3+, Er3+, Bi3+ phosphor are explored. The CaWO4: Yb3+, Er3+, Bi3+ phosphor is formulated into the inks, printed on the flexible substrate by the screen-printing technology. The luminescence color of printed various patterns can be changed based on the dual-mode luminescence modification, which demonstrate that the CaWO4: Yb3+, Er3+, Bi3+ phosphor ink is an ideal multiple anti-counterfeiting agent. The optical information recorded on the binary photochromic dot arrays of CaWO4: Yb3+, Er3+, Bi3+ sheet could be read upon the UV and near infrared light excitation, exhibiting the potential application of CaWO4: Yb3+, Er3+, Bi3+ phosphor as optical data storage medium.

Surface characteristics and flotation behaviours of specularite as influenced by lead ion modification

Specularite is generally recovered by flotation, but its floatability is relatively weak. Activation is an effective method to improve the floatability of minerals. Therefore, finding an economic and effective activator to improve the recovery of specularite is an important research direction. In this study, lead nitrate as an activator was found and confirmed to improve the floatability of specularite. Its activation mechanism was further investigated by various analytical methods. The micro-flotation tests results showed that the recovery of specularite increased from 69.57% to 92.47% at a Pb2+ concentration of 3 × 10-5 mol/L, an approximately 23% increase, indicating that Pb2+ could obviously activate specularite. The SEM-EDS results illustrated that the content of Pb on the specularite surface apparently increased after specularite treatment with lead nitrate, which confirmed the adsorption of Pb species on the surface of specularite. Zeta potential results showed that the zeta potential positively shifted within the pH range from 3 to 11, which was beneficial to the occurrence of electrostatic adsorption and chemisorption between negatively charged oleate species and specularite. XPS results revealed that lead species mainly adsorbed on the O atoms of Fe-O and Fe-OH at the specularite surface, and Pb atoms became new sites to interact with sodium oleate. In addition, Pb2+ and Pb(OH)+ were the predominant components that interacted with the specularite surface and formed -O-Pb and Fe-O-Pb complexes, which considerably increased the number of reactive sites on the specularite surface. After oleate components interacted with Pb-modified specularite, a denser hydrophobic layer was generated on the surface of specularite, which intensified the floatability of specularite.

Ion modification of transition cobalt oxide by soaking strategy for enhanced water splitting

Heterostructure engineering carries prime importance to enhance the catalytic activity of electrocatalysts for water splitting. However, developing nonprecious metal oxides as splendid bifunctional electrocatalysts in alkaline conditions remains a great challenge. Herein, we developed a smart soaking strategy of sulfur/iron ion modification, by which we could activate Co3O4 to spontaneously form heterogeneous structure with excellent hydrogen/oxygen evolution reaction (HER/OER) performance. The nickel foam supported Co3O4 nanoarrays embellished with NiCoSx (NiCoSx@Co3O4 NAs/NF) was easily obtained via sulfur ion modification, which has rich oxygen vacancies and active sites, leading to an outstanding HER performance (η10 = 59 mV, η400 = 264.0 mV). Furthermore, Fe(Ⅱ) ion modified NiCoSx@Co3O4 NAs/NF (FeNiCoS@Co3O4 NAs/NF) achieved superior OER performance (η10 = 226 mV, η400 = 302 mV) than other recently reported cobalt-based catalysts due to the synergistic activity of Ni-Fe-S-Co. More importantly, this work offered a facile and energy-free strategy for developing transition metal oxides as splendid bifunctional catalysts and contributed to the cost and energy savings and mass production for industrial applications as well as the design of advanced functional materials for energy chemistry.

In vitro investigation of the cell compatibility and antibacterial properties of titanium treated with calcium and ozone.

The purpose of this study was to evaluate the surface modification of calcium ions on roughened titanium as a surface treatment of dental implants for cell attachment, growth, and initial bacterial adhesion. When a surface-roughened, pure titanium disk was immersed in a calcium chloride solution (100 mM) containing 20 ppm ozone for 24 h at 25ºC, calcium was detected on the surface by X-ray photoelectron spectroscopy. The calcium-modified, roughened titanium disk had a significantly greater concentration of the initially adhered cells as well as cells cultured over 7 days compared with titanium disks without surface modification. Furthermore, the initial bacterial adhesion on the calcium-ozone treated titanium disk was statistically less than on a pure titanium disk or titanium disk treated without ozone. Dissolved ozone was useful for modifying the surface of roughened titanium with calcium ions and the surface modification may be applicable for dental implants.

Cationic intermediates assisted self-assembly two-dimensional Ti3C2Tx/rGO hybrid nanoflakes for advanced lithium-ion capacitors

Two-dimensional (2D) material MXenes have been intensively concerned in energy-storage field due to these unique properties of metallic-like conductivity, good hydrophilicity and high volumetric capacity. However, the self-restocking of ultra-thin 2D materials seriously hinders these performances, which significantly inhibits the full exploitation of MXenes in the field of energy storage. To solve this issue, a strategy to prepare delaminated Ti3C2Tx (MXene) nanoflakes/reduced graphene oxide (rGO) composites is proposed using the electrostatic self-assembly between positively charged Ti3C2Tx with tetrabutylammonium ion (TBA+) modification and negatively charged graphene. The nanoflakes of Ti3C2Tx/rGO are well dispersed and arranged in a face-to-face structure to effectively alleviate the self-restacking and provide more electroactive sites for accessible of electrolyte ions. The prepared delaminated Ti3C2Tx/rGO anode shows a high reversible capacity up to 1394 mAh g−1 at a current density of 50 mA g−1. Moreover, a lithium-ion capacitor (LIC) was assembled with delaminated Ti3C2Tx/rGO anode and activated carbon (AC) cathode which can exhibit a specific capacity of 70.7 F g−1 at a current density of 0.1 A g−1 and deliver an ultrahigh energy density of 114 Wh kg−1 at a relatively high power density of 3125 W kg−1. These good electrochemical performances demonstrate the potential of delaminated Ti3C2Tx/rGO as an anode material for lithium-ion capacitors.

Modulation of Metal Halide Structural Units for Light Emission.

ConspectusWith the development of solid-state lighting technology, efficient light sources that combine high brightness, wide range, and good stability are in high demand for next-generation lighting and displays. Metal halides are emerging as promising luminescent materials due to their versatility for desirable light emission manipulations. This is because the optical activity of the metal halide material depends on the metal halide structural unit and the organic ions or coordinated organic ligands. The different assembly of metal halide units and organic parts can enable versatile light emissions, such as lead halide perovskites (LHPs) and copper halide-organic hybrids. Impressively, the external quantum efficiency of the LHP based light-emitting diodes (LEDs) has improved significantly from 0.1% to over 20% in just five years. With this great progress, the structural lability and toxicity of the LHPs are now the critical issues that need to be addressed for practical applications. These issues are mainly rooted in the intrinsic lead composition and low formation energy crystal structure of the widely adopted LHPs. Thus, the modulation of the structure and composition of the basic metal halide structural units is considered a rational strategy to address these issues.In this Account, we will present a general material design using metal halide structural units as basic building blocks to build up metal halide luminescent materials for solid-state lighting devices. Following this route, we will emphasize the modulation of metal halide structural units to tackle the existing challenges in lead halides, including the instability of crystalline structure, ion migration, and the presence of toxic lead. Considering basic components in structural units, we will highlight ionic engineering in LHPs via ion doping, substitution, and modification to enhance the crystal structural stability and suppress ion migration. To replace toxic lead, we will introduce recent advances in the modulation of lead-free halide structural units by active ion doping and organic ligand coordination to fabricate highly luminescent materials. Finally, we will present future strategies of metal halide structural unit modulation for solid-state light emissions. We hope this Account will provide new insights for designing metal halide materials from the viewpoint of the modulation of the basic building blocks and inspire future studies of advanced metal halide materials for solid-state light emitting applications.

Preparation and properties of negative ion functional cotton knitted fabric

In order to develop negative ion functional cotton knitting products with good performance, tourmaline powder was selected as the anion additive, and the anion functional finishing of cotton knitting products was carried out by the two-dip and two-rolling process. The microstructures of tourmaline powder and anion functional cotton fabric were observed, their anion emissions were measured, and the influences of particle size and amount of anion additive on the finishing effect were discussed. The results showed that, after grinding, the particle size of tourmaline powder decreased to different degrees and its distribution was more uniform. The negative ion emission of tourmaline powder was enhanced compared with that before grinding. The properties of cotton knitted fabric treated with ground negative ion additive were better than those treated with non-ground one. The contents of negative ion additive and modification temperature both have great influence on the amount of anion emission of finished cotton fabric. The anion functional cotton fabric had certain washing durability and needs to be improve.

Simultaneously improved transparency, photochromic contrast and Curie temperatureviarare-earth ion modification in KNN-based ceramics

Higher temperature sintering and donor doping caused a series of changes, such as vacancy defects, microstructure and relaxor-feature, which led to the simultaneous improvement of optical transparency, PC contrast andTcof the KNNLB-RE ceramics.

Preparation and performance of novel APP/NaY–Fe suppressant for coal dust explosion

Coal dust explosion occurs easily in the coal chemical industry. To ensure safety in industrial production, NaY zeolite was used as carrier modified with Fe ions and combined with ammonium polyphosphate (APP) to prepare a novel composite suppressant for coal dust explosion. The explosion suppression performance of novel APP/NaY–Fe suppressant was investigated by flame propagation inhibition experiments. The results show that Fe ion modification can effectively improve the explosion suppression performance. By increasing content, the explosion suppression performance of the explosion suppressant increases. The maximum explosion pressure Pmax of coal dust drops to 0.13 MPa when 50 wt% explosion suppressants were added, and the coal dust explosion cannot continue to expand. Complete suppression of explosion could be achieved by adding 66 wt% explosion suppressants. Combined with XRD, SEM and TG results, the explosion suppression mechanism was proposed. The novel explosion suppressant has high thermal stability, good dispersity and its explosion suppression components distribute uniformly. It shows good explosion suppression performance by the synergistic effect among explosion-suppression components.

Ion irradiation and modification: The role of coupled electronic and nuclear energy dissipation and subsequent nonequilibrium processes in materials

Understanding material responses to energy deposition from energetic charged particles is important for defect engineering, ion-beam processing, ion-beam analysis and modification, geologic aging, space exploration, and nuclear applications. As an incident ion penetrates a solid, its energy is transferred to electrons and to atomic nuclei of the solid. Much of this electronic energy deposition is subsequently transferred to the atomic structure via electron–phonon (e–ph) coupling, leading to local inelastic thermal spikes in which energy dissipation is influenced by the local environment. In addition, intense ionization can lead to high densities of localized electronic excitations in wide-bandgap materials and ceramics that can affect defect dynamics and atomic mobility. Specifically, energy exchange between electrons and atomic nuclei, along with localized electronic excitations, can lead to substantial competitive (ionization-induced annealing), additive (both electronic and nuclear energy depositions contributing to damage production), and synergistic (more damage than the sums of separate damage processes) effects. Although nonmonotonic effects of the e–ph coupling strength and athermal processes are demonstrated for pre-existing defects and residual damage during ion–solid interactions, there is limited understanding of when such electronic effects must be considered in atomic-scale models of damage production and evolution in a broad variety of materials. Complex ceramics and chemically disordered solid solution alloys with different constituent elements allow a systematic evaluation of defect dynamics and irradiation performance with increasing complexity. Current knowledge regarding tuning of bonding characteristics and chemical disorder to control atomic-level dynamics is reviewed. Although a lack of fundamental understanding obstructs the advancement of reliable predictions for ion beam material modification, it highlights challenges and opens research opportunities. Insights into the complex electronic and atomic correlations with extreme energy deposition will strengthen our ability to design materials and predict ion-irradiation-induced damage in a radiation environment, and they may pave the way to better control fundamental processes and design new material functionalities for advanced technologies.

Designable Carboxymethylpachymaran/Metal Ion Architecture on Sunflower Sporopollenin Exine Capsules as Delivery Vehicles for Bioactive Macromolecules.

There are multiple obstacles in the gastrointestinal tract (GIT) for oral administration of bioactive macromolecules. Here, we engineered an oral delivery vehicle (sporopollenin exine capsules with carboxymethylpachymaran (CMP)/metal ion modification) with targeted release based on food-grade ingredients and processing operations. Then, the interaction and binding mechanisms between CMP and metal ions in the vehicle were investigated. By using β-galactosidase (β-Gal) as a model protein, the systems were characterized for the surface morphology and monitored by the in vitro release profile of β-Gal. Notably, the CMP/metal ion systems not only markedly decreased the CMP dosage but also achieved a valid long-term release compared with the previously reported CMP system. Among all the systems, the CMP/3% AlCl3 system showed the best ability to control the release with the maximum residual activity of β-Gal at nearly 72% after 24 h of treatment. Subsequently, the interaction mechanism between CMP and metal ions within the system was characterized by the perspectives of microstructure, rheological properties, and spectroscopy characteristics. The results indicated that the low pH conditions are conducive to the further cross-linking of CMP and metal ions, resulting in a high gel strength and thus a dense structure, which can impact the controlled release of β-Gal in the GIT. Overall, the system may be utilized in the administration of medical and functional foods, specifically for the delivery of bioactive proteins via the oral route.

Aom2 S: A new web-based application for DNA/RNA tandem mass spectrometry data interpretation.

The Analysis of Oligonucleotide Modifications from Mass Spectra (Aom2 S) was created to support the analysis of oligonucleotide mass spectra. This application complements the existing software tools by providing a comprehensive analysis of oligonucleotide fragments from high-resolution tandem mass spectrometry (HR-MS/MS) data in a flexible and user-friendly manner, directly accessible through a web browser without any need for installation. MS measurements of aminoC6-DNA and inosine-RNA were performed using an LTQ Orbitrap FT-MS instrument. The obtained data were analyzed by our newly developed open-source package Aom2 S accessible from the ms.epfl.ch web page or directly at https://mstools.epfl.ch/am2s/ to demonstrate the various functionalities of this tool, notably the possibility to identify different product ions from a nucleotide sequence with any fixed/variable modification by matching theoretical isotopic patterns to any experimental mass spectra with similarity scores ranking. A detailed description of the Aom2 S tool with its user-friendly interface is exemplified using HR-MS/MS data of modified DNA and RNA oligonucleotides. Explanations of analysis parameters and tool workflow, as well as multiple options for viewing and exporting the results, are provided. Product ion assignment and modification localization can be achieved in seconds, and results can be exported as tables, matched mass spectra, and fragmentation maps. A new open source tool (Aom2 S) for the analysis of HR-MS/MS data for modified DNA and RNA oligonucleotides is described. Aom2 S is fast, highly flexible, and versatile, allowing automatic precursor and product ion assignment in a comprehensive manner, including internal fragments and variable modification localization, with clear graphical representation of the results.