- Prussian Blue modified Metal Organic Frameworks for imaging guided synergetic tumor therapy with hypoxia modulation
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In this study, a hybrid material UIO-66-NH2/PB were synthesized through the modification of Prussian Blue on the surface of Metal Organic Frameworks for synergetic tumor therapy with hypoxia modulation. It was found that UIO-66-NH2/PB has good photo-thermal performance and photo-thermal stability, suitable for photo-thermal treatment. Dissolved oxygen analysis showed that UIO-66-NH2/PB can catalyze H2O2 into O2. It was proved that this process is accompanied by the generation of ·OH. Furthermore, with the irradiation of 808 nm for 5min, the TMB solution becomes darker blue, proving that more free radicals are produced. The produced O2 can be used to modulate the hypoxia of tumor to improve the anti-cancer efficiency, and the generated ·OH can kill cancer cells to achieve chemo-dynamic therapy. Doxorubicin (DOX) was selected as a model drug and the DOX loading of UIO-66-NH2/PB was 67%. Drug release experiments showed that DOX was not nearly released in pH 7.4, while 78% DOX was released in pH5.8 after 40 h, demonstrating the excellent pH-responsive release. In addition, with the irradiation of 808 nm for 5min, 87% DOX was released in pH 5.8, indicating photo-thermal effect could help achieve better release effect. The different cytotoxicity to L-02 cells and HeLa cells of UIO-66-NH2/PB shows UIO-66-NH2/PB is only harmful to cancer cells, indicating that Fenton-like reaction only occurred in tumor to generate ·OH. In vivo experiment showed synergetic therapy can achieve satisfactory treatment efficiency. Therefore, UIO-66-NH2/PB is expected to combine multiple treatments to improve anti-cancer effect.
- Chi, Bin,Gao, Haiqing,Li, Ling,Tian, Feng,Wang, Jing,Xu, Mingyue,Xu, Zushun
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- Transient Spectroscopy of the Redox Reactions of the Prussian Blue Membrane Having Electronic State Gradient
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The transient spectroscopic studies were carried out on a Prussian Blue (PB) membrane coated on an ITO electrode (5 cm x 1 cm), on which an electronic state gradient was realized.An isosbestic point was clearly observed in the transient spectral changes when the PB was oxidized upon application of a potential from open-circuit to 1.5 V difference between the membrane terminals.The transient spectra observed on stepping back to open circuit showed three isosbestic points from the entirely oxidized state to the reduced states, to which a new electron transfer process is proposed.
- Toshima, Naoki,Lin, Ru-Jang,Kaneko, Masao
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- Photosynthesis and characterization of Prussian blue nanocubes on surfaces of TiO2 colloids
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Prussian blue (PB) nanocubes were synthesized on the surface of titania (Ti O2) colloids using two-step process with ultraviolet light illumination. The formation of PB nanocubes starts with its nucleation under strong ultraviolet light illumination and followed by a slow growth of the nuclei under low intensity natural light illumination. This kind of PB nanocube has a very low Curie temperature.
- Song, Yan-Yan,Zhang, Ke,Xia, Xing-Hua
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- WATER PHOTOLYSIS BY MEANS OF VISIBLE LIGHT WITH A SYSTEM COMPOSED OF PRUSSIAN BLUE AND THE TRIS(2,2 prime -BIPYRIDINE)RUTHENIUM(II) COMPLEX.
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A water-photolysis system composed of Prussian Blue (PB) and the tris(2,2 prime -bipyridine)ruthenium(II) complex( left bracket Ru(bpy)//3 right bracket **2** plus ) which evolves hydrogen and oxygen simultaneously was studied. Both the components worked catalytically in the photolysis. PB provides active sites for both H//2 and O//2 evolution. The dependence on the pH showed optimum conditions at pH 2. The photolysis required the presence of a cation, and only such cations as K** plus and Rb** plus whose hydrated ions are smaller than the pore size of the PB lattice were active for the reaction. The dependence on the KCl concentration showed an optimum point at 0. 5 mol dm** minus **3.
- Kaneko,Takabayashi,Yamauchi,Yamada
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- Electrochemical Study of Microcrystalline Solid Prussian Blue Particles Mechancally Attached to Graphite and Gold Electrodes: Electrochemically Induced Lattice
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The voltammetric behavior of solid Prussian blue mechanically attached to graphite, glassy carbon, or gold electrodes as an array of microscopically small particles is extremely well defined when the electrode is placed in aqueous media containing suitabl
- Dostal, Ales,Meyer, Birgit,Scholz, Fritz,Schroeder, Uwe,Bond, Alan M.,et al.
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- Hierarchical porous hollow FeFe(CN)6 nanospheres wrapped with I-doped graphene as anode materials for lithium-ion batteries
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Hierarchical porous hollow FeFe(CN)6 nanospheres were synthesized via a facile anisotropic chemical etching route at different temperatures. Herein, we integrated these FeFe(CN)6 nanospheres and conductive iodine-doped graphene (IG) into a lithium-ion battery (LIB) system, FeFe(CN)6@IG. The hollow Prussian-blue type FeFe(CN)6 nanospheres with an average particle size of 230 nm are uniformly and tightly encapsulated by IG sheets. As an anode material for LIBs, the fabricated FeFe(CN)6@IG exhibits high specific capacity, excellent rate properties, and superior cycling stability. A reversible capacity can be maintained at 709 mA h g-1 after 250 cycles at a current density of 1000 mA g-1. Even at a current rate of 2000 mA g-1, the capacity could reach 473 mA h g-1. This facile fabrication strategy may pave the way for constructing high performance Prussian blue-based anode materials for potential application in advanced lithium-ion batteries.
- Ren, Zhengxin,Hu, Die,Zhang, Xiannan,Liu, Dan,Wang, Cheng
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- Study of Growth and the Electrochemical Behavior of Prussian Blue Films Using Electrochemical Quartz Crystal Microbalance
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Using cyclic voltammetry and chronoamperometry combined with electrochemical quartz crystal microbalance, the deposition of Prussian blue (PB) on a gold electrode from solutions containing Fe3+ and Fe(CN)03-) ions was studied. The change of mass in cyclic voltammetry experiments in the first cycles points to fast deposition of PB. In longer cycling the exit and entrance of cations (K+, NH4+) is observed in the anodic and cathodic run, respectively. In potentiostatic deposition four types of behaviors of the mass (and charge) change in time as functions of potential were found. The results point to the electrodeposition of a mixture of the insoluble and soluble form of PB in the range 0.55-0.25 V. Energy-dispersive X-ray (EDX) analysis indicates that at 0.35 V both soluble and insoluble PB is formed. Prolonged cycling of such electrodes in KCl solutions does not change the K:Fe ratio. At 0.10 V K2Fe[Fe(CN)6] is obtained. The solubility products of KFe[Fe(CN)6] and Fe4[Fe(CN)6]3 were estimated based on the potentiostatic deposition experiments. The process of the dissolution of the PB deposits under potentiostatic conditions at positive potentials was also studied and the rate of dissolution was calculated. When the PB layers on the electrode are very thin, the change of mass shows that, as a net result, nonhydrated potassium ions exit or enter the layer in the redox reactions. Similar behavior is observed for ammonium ions. Smaller values of apparent molar mass are found when thicker PB layers are used.
- Zadronecki, Marcin,Wrona, Piotr K.,Galus, Zbigniew
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- A novel Prussian blue-magnetite composite synthesized by self-template method and its application in reduction of hydrogen peroxide
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A novel Prussian blue (PB)-Fe3O4 composite has been prepared for the first time by self-template method using PB as the precursor. According to this method, Fe3O4 nanoparticles distributed uniformly on the surface of PB cube. The feed ratio of sodium acetate to PB has been proved to be a key factor for magnetic properties and electro-catalysis properties of the composite. Under the experimental conditions, the saturation magnetization value (Ms) of PB-Fe3O4–2 composite was 22 emug?1, while the Ms value of other samples reduced. The composites also showed a good peroxidase-like activity for the oxidation of substrate 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2. The catalytic reduction of hydrogen peroxide capacity was PB-Fe3O4–1>?PB-Fe3O4–2>?PB-Fe3O4–3>?PB-Fe3O4–0, which confirmed the Fe(II) centres in PB surface and Fe3O4 nanoparticles had synergistic effect on catalytic reduction of hydrogen peroxide.
- Cai, Wei,Wu, Songhai,Liu, Yong,Li, Danlin
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- Prussian blue-doped PAMAM dendrimer nanospheres for electrochemical immunoassay of human plasma cardiac troponin i without enzymatic amplification
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Rapid and accurate identification of cardiac troponin I (cTnl) in biological fluids is very essential for judging acute myocardial infarction (AMI). Herein, we constructed an enzyme-free electrochemical immunosensing system for sensitive monitoring of human plasma cTnl cardio-cerebrovascular diseases. Prussian blue-doped PAMAM dendrimer nanospheres (PBDENPs) were first synthesized by using in situ chemical reaction, and functionalized with polyclonal anti-human cTnl antibody as the signal-transduction tags. Field-emission transmission electron microscopy (FETEM), dynamic light scattering (DLS), and scanning electron microscopy (SEM) were utilized for characterization of the immunosensing platform. By using a monoclonal anti-human cTnl antibody-modified screen-printed carbon electrode (SPCE) as the immunsensing interface and polyclonal anti-cTnl antibody-labeled PBDENPs and the signal tags, a new sandwich-type immunoassay was designed for the determination of target cTnl by using square wave voltammetry (SWV). Multi-armed dendritic PAMAM nanospheres were expected to enhance the detectable signal of electrochemical immunoassay through the doped Prussian blue with electrochemical activity. Under optimum conditions, the enzyme-free electrochemical immunoassay displayed a wide linear range of four orders of magnitude from 0.01 ng mL-1 to 100 ng mL-1 with a low detection limit of 6.2 pg mL-1 cTnl at the 3sB criterion. An intermediate precision of ≤10.9% was accomplished with batch-to-batch identification, and good anti-interference capacity against other cancer biomarkers or proteins was acquired toward target cTnl. In addition, measurements of human serum specimens were demonstrated to further confirm the method accuracy of electrochemical immunoassay, and well-matched results were obtained between the electrochemical immunoassay and the referenced enzyme-linked immunosorbent assay (ELISA) method.
- Ma, Fangfang,Ge, Gaoshun,Fang, Yizhen,Ni, Erru,Su, Yuanyuan,Cai, Fan,Xie, Huabin
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- Improved electrochemical performances of LiNi0.6Co0.2Mn0.2O2 cathode material by reducing lithium residues with the coating of Prussian blue
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Reducing the lithium residues on the surface of LiNi0.6Co0.2Mn0.2O2 (NCM) cathode is one of the most main challenges in Li-ion battery research. To address this task, a surface coating of Prussian blue (PB) of metal-organic framework is applied to NCM cathode to solve this intractable problem via a simple dry-coating method. The transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) results show that the uniform smooth coating can provide a protective shell to block H2O and CO2 absorption from the air, suppressing lithium residues formed on the surface. The color change experiment between PB and Li residuals illustrates PB can react directly with surface residual lithium species. As a result, the amount of residual lithium, such as LiOH and Li2CO3, is significantly reduced. The 0.5 wt% PB-modified NCM delivers a high discharge capacity retention of 81% after 500 cycles at 1 C discharge rate and exhibits a superior storage property after storing in air for 14 days. Furthermore, electrochemical impedance spectroscopy (EIS) confirms that the PB-NCM could hinder the impedance increase during cycling. These results clearly indicate that the PB coating layer contributes to the reduction of lithium residues and the creation of thinner cathode-electrolyte interface, improving structural stability and cycling performance of NCM.
- Ding, Yan,Deng, Bangwei,Wang, Hao,Li, Xiang,Chen, Tao,Yan, Xinxiu,Wan, Qi,Qu, Meizhen,Peng, Gongchang
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- Study of Prussian Blue (PB) films by ac-electrogravimetry: Influence of PB morphology on ions movement
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The electrochemical response of Prussian Blue films in NaCl solutions was studied. It was proved that the stability with cycling of PB films increased when these films are covered with a Nafion membrane. This fact allows PB films to be studied in NaCl solutions under steady state conditions by impedance spectroscopy and ac-electrogravimetry. A model, which can explain the differences between the electrochemical behaviour of amorphous PB films and crystalline PB films in NaCl solutions, is proposed. This model is based on the hypothesis of a partial dehydration of the sodium ions before the electrochemical reactions take place, allowing the transport of sodium ions through the zeolitic channels of Prussian Blue.
- Garcia-Jareno,Sanmatias,Vicente,Gabrielli,Keddam,Perrot
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- Electrochemical sensor with record performance characteristics
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Nanoelectrode sensor arrays were formed by depositing nanostructures of the electrocatalyst Prussian Blue onto an inert carbon support. The sensor thus obtained showed a high sensitivity toward hydrogen peroxide, with a detection limit of 1 × 10-9 mol L-1 (i.e., 0.03 ppb), and a broad linear calibration range, which extended over seven orders of magnitude (from 10-9 to 10-2 M L-1 H2O 2, see graphic). (Graph Presented).
- Karyakin, Arkady A.,Puganova, Elena A.,Bolshakov, Ivan A.,Karyakina, Elena E.
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- Spectroelectrochemistry of New Prussian Blue Films Prepared by a Cast Method
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New Prussian Blue (PB) films were prepared by being cast from colloidal PB dispersions in an organic solvent containing cationic surfactants.The electrochromic behaviors of the cast PB films are similar to those of electrodeposited PB films.However, the cyclic voltammetries of both the PB films were quite different from each other.To make the difference clear, scanning electron microscopy (SEM), energy dipersive X-ray analysis (EDX), and X-ray photospectroscopy (XPS) were used in measurements of these films grown on Pt and indium tin oxide electrodes.The EDX results for fresh PB films indicated that cast films contain K+ ions, suggesting a soluble-form PB, KFe, while electrodeposited films do not, suggesting an insoluble-form PB, Fe43.The transient spectral observations indicated the participation of a unique electrochemically active iron(III) site in the reductive cycles of a cast film, although the participation of a plural electrochemically active iron(III) sites was proposed for an electrodeposited film.After a repeated cyclic scan a cast PB film maintained its unique active site, while an electrodeposited film had plural sites comprising both a soluble and an insoluble form of PB.
- Lin, Ru-Jang,Toshima, Naoki
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- Formation of Fe2O3 microboxes with hierarchical shell structures from metal-organic frameworks and their lithium storage properties
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Fe2O3 microboxes with hierarchically structured shells have been synthesized simply by annealing Prussian blue (PB) microcubes. By utilizing simultaneous oxidative decomposition of PB microcubes and crystal growth of iron oxide shells, we have demonstrated a scalable synthesis of anisotropic hollow structures with various shell architectures. When evaluated as an anode material for lithium ion batteries, the Fe2O3 microboxes with a well-defined hollow structure and hierarchical shell manifested high specific capacity (~950 mA h g-1 at 200 mA g -1) and excellent cycling performance.
- Zhang, Lei,Wu, Hao Bin,Madhavi, Srinivasan,Hng, Huey Hoon,Lou, Xiong Wen
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- On the Onsager's phenomenological coefficient of Prussian blue electrochemical redox system
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Diffusion towards solid film in an electrochemical system was studied from nonequilibrium thermodynamic point of view. To this aim, electrochemical redox of Prussian blue in the presence of different supporting electrolyte cations was chosen as a well-known system. The variation of the phenomenological coefficient was investigated. The theory derived from theoretical hypothesis was supported by experimental results obtained from chronoamperimetric and cyclic voltammetric measurements. The fulfillment of reciprocity Onsager relation was also presented. Interestingly, it was demonstrated that the phenomenological coefficient for a diffusing electrochemical system is strongly time-dependent, and can be considered as a dynamic representative of the flux.
- Eftekhari, Ali
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- Facile fabrication of a Prussian Blue film by direct aerosol deposition on a Pt electrode
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A facile aerosol deposition approach, which was simulated as feasible by density functional theory (DFT), was applied to synthesize a Prussian Blue (PB) film directly on a Pt electrode surface.
- Chu, Zhenyu,Liu, Yu,Jin, Wanqin,Xu, Nanping,Tieke, Bernd
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- A simple chemical method for deposition of electrochromic Prussian blue thin films
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This paper is about a recently developed new chemical method for deposition of Prussian blue thin films. The films are easily prepared by successive immersion of the substrates into an acidic aqueous solution of Fe 2(SO4)3 and K4[Fe(CN)6]. It is calculated of the results from AFM analysis that the growth in the film thickness by one immersion cycle corresponds to an average increase of 6 nm. The characterization of the films with X-ray diffraction, SEM-EDS analysis and FTIR spectroscopy shows that the deposited material is amorphous hydrated Fe 4[Fe(CN)6]3. The electrochromic properties are characterized by cyclic voltammetry and VIS spectrophotometry. The PB thin films exhibit stability and excellent reversibility, which make these films favorable for electrochromic devices.
- Demiri, Sani,Najdoski, Metodija,Velevska, Julijana
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- Ellipsometric investigation of the formation and conversion of Prussian blue films
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Ellipsometry has been used to study the formation and electrochromic conversion of Prussian blue films. A Prussian blue film can be deposited on a metal substrate in an appropriate electrolyte by applying a cathodic current. Once grown, a given film can be cycled from its original blue color to a transparent state by applying a cathodic current. The film can also be cycled back to a blue color again with an anodic current; however, the blue film after the first and subsequent cycles has optical properties that differ from the original blue film. At potentials higher than that which return the film to its blue color, the film changes once more, but if the potential is allowed to become too high, the film changes in an irreversible manner.
- Beckstead,De Smet,Ord
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- Electrochemically prepared poly(o-phenylenediamine) - Prussian Blue composite film for a three-colour expressible ECD material
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Both Prussian blue (PB) and poly(o-phenylenediamine) (PoPD) were easily electrodeposited as stable films onto a transparent indium tin oxide (ITO) electrode. The voltammogram of the PB film showed a reversible sharp redox peak current at about 0.25 V. Although the colour change was caused by altering the applied potentials, no colour change was seen after about 104 repetitions. The PoPD film also showed a reversible redox peak current at about -0.05 V. The redox reaction was accompanied by a readily observable colour change between nearly red (vermilion) and colourless. The PoPD film was electrodeposited onto the PB coated electrode to obtain a PB/PoPD composite film. The voltammogram of the film was comprised of the two redox waves of the individual components. The film retained the electrochromic properties of each component and there was no undesirable interference. By changing the potentials, the film exhibited a continuous variety of colours: colourless (-0.2 V), vermilion (0.1 V) and emerald green (0.6 V). The switching time of the colour change was found to be 5 repetitions since the PoPD worked as a binder which enhanced the adhesion of PB to the electrode surface.
- Yano,Terayama,Yamasaki
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- Graphene-based electrochromic systems: The case of Prussian Blue nanoparticles on transparent graphene film
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Prussian Blue nanoparticles were electrodeposited on transparent grapheme film, which showed a promising electrochromism with response times in the range of 3.3-38 s. The Royal Society of Chemistry 2012.
- Ko, Ju Hong,Yeo, Soojung,Park, Ji Hoon,Choi, Jaewon,Noh, Changho,Son, Seung Uk
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- Ac-electrogravimetry study of electroactive thin films. I. Application to Prussian Blue
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Prussian Blue films were investigated by Using ac-electrogravimetry, that is, simultaneous impedance and electrogravimetry spectroscopies at different potentials between the totally reduced form, Everitt's salt, and the mixed-valence compound, Prussian Bl
- Gabrielli, Claude,Garciì?a-Jarenì?o, Jose J.,Keddam, Michel,Perrot, Hubert,Vicente, Francisco
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- A Universal Strategy toward Ultrasmall Hollow Nanostructures with Remarkable Electrochemical Performance
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A facile and versatile microwave-assisted and shell-confined Kirkendall diffusion strategy is used to fabricate ultrasmall hollow nanoparticles by modulating the growth and thermal conversion of metal–organic framework (MOF) nanocrystals on graphene. This method involves that the adsorption of microwave by graphene creates a high-energy environment in a short time to decompose the in situ grown MOF nanocrystals into well-dispersed uniform core–shell nanoparticles with ultrasmall size. Upon a shell-confined Kirkendall diffusion process, hollow nanoparticles of multi-metal oxides, phosphides, and sulfides with the diameter below 20 nm and shell thickness below 3 nm can be obtained for the first time. Ultrasmall hollow nanostructures such as Fe2O3 can promote much faster charge transport and expose more active sites as well as migrate the volume change stress more efficiently than the solid and large hollow counterparts, thus demonstrating remarkable lithium-ion storage performance.
- Aboud, Mohamed F. Aly,Fan, Minmin,Liao, Dankui,Shakir, Imran,Xu, Yuxi
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- Electrodeposited Prussian blue films: Annealing effect
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The correlation between the temperature-dependent electrochromic (EC) activity and other properties of galvanostatically deposited Prussian Blue (PB) films is presented here. Films subjected to annealing treatment in air at temperatures up to 500 °C were characterized by a variety of techniques which include TGA, XRD, FTIR, UV-vis spectrophotometry, SEM, XPS, cyclic voltammetry etc. The as-deposited X-ray amorphous hydrated PB films were blue in color and had Fe in both FeII and FeIII valence states and were electrochromically active. Consequent to changes in the valence state, degree of hydration and coordination environment of the iron ions upon annealing, EC activity and morphology of the films exhibited dramatic changes. Annealing at moderate temperatures retained the blue color of the films and decreased the EC activity consistent with dehydration and decreased the FeII content. Lack of EC activity at higher temperatures was consistent with dehydration and quenching of FeII states accompanied with change of color from blue to rust (FeIII) typical of Fe2O3. Independent of the annealing temperature, the films retained their amorphicity, however, prolonged annealing at 500 °C yielded hexagonal Fe2O3.
- Agnihotry,Singh, Punita,Joshi, Amish G.,Singh,Sood,Shivaprasad
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- Self-assembled films of Prussian blue and analogues: Structure and morphology, elemental composition, film growth, and nanosieving of ions
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Structure, morphology, and elemental composition as well as the size-selectivity of the ion transport behavior of ultrathin membranes of iron(III) hexacyanoferrate(II) (FeIIIHCFII), iron(II) hexacyanoferrate(III) (FeIIHCFIII), cobalt(II) hexacyanoferrate(III) (CoIIHCFIII), and nickel(II) hexacynoferrate(III) (NiIIHCFIII) are described. The membranes were prepared upon multiple sequential adsorption of metal cations and hexacyanometalate anions on porous polymer supports. Scanning electron and scanning force microscopy indicate that the membranes of the complex salts consists of a multitude of small, densely packed particles with diameter in the 10-100 nm range. Energy-dispersive X-ray analysis indicates that the ion hexacyanoferrate (Prussian blue) membranes consist of the potassium-rich, so-called soluble modification, KFe[Fe(CN)6], while the membranes of the analogous complex salts consists of a mixture of the potassium-rich and potassium-free modification. The porous, zeolitic structure of the inorganic complex salts was permeable for ions with small Stokes radius such as Cs+, K+, and Cl-, whereas large hydrated ions such as Na+, Li-, Mg2-, or SO42- were blocked. Ion separation became progressively more effective, if the number of complex layers increased. The highest separation factors α(CsCl/NaCl) and α(KCl/NaCl) of 7.7 and 5.9, respectively, were found for the FeIIIHCFII membrane subjected to a hundred dipping cycles. Membranes of iron(II), cobalt(II), and nickel(II) hexacyanoferrate(III) were also useful for ion separation, but the α values were lower. Effects on the ion flux rates caused by the feed concentration and the polyelectrolyte precoating of the support are also discussed.
- Jin, Wanqin,Toutianoush, Ali,Pyrasch, Mario,Schnepf, Judit,Gottschalk, Helmut,Rammensee, Werner,Tieke, Bernd
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- Synthesis and properties of modified fillers based on calcium and magnesium carbonates
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A possibility of modifying natural carbonate fillers for paint and varnish industry by solutions of salts of some nonferrous metals was studied. Reactions of carbonates with metal ions and physicotechnical properties of the resulting materials were considered.
- Shashkova,Rat'ko,Koshevar,Kitikova,D'Yachenko
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- Neutron diffraction study of Prussian Blue, Fe4[Fe(CN)6]3·xH2O. Location of water molecules and long-range magnetic order
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Prussian Blue, Fe4[Fe(CN)6]3·xH2O (x = 14-16), has been studied by powder neutron diffraction in four different states of hydration: dehydrated, x(H,D)2O with a vanishing scattering contribution of hydrogen, xD2O, and xH2O. Structural calculations using diffraction profile analysis reveal two structurally distinguishable kinds of water molecules. Six molecules of water are coordinated to Fe(III) at empty nitrogen sites; approximately eight additional water molecules are present either as isolated molecules at the center of the unit cell octants or as water molecules connected by hydrogen bonds to the coordinated ones. The corresponding O-D-O distance amounts to 2.87 A?. The disordered overall structure is described as a superposition of various ordered substructures. Magnetic contributions to the neutron intensities below the Curie temperature of 5.6 K reveal ferromagnetism. The magnetic part of the intensities corresponds to S = 5/2 of high-spin Fe(III).
- Herren,Fischer,Ludi,H?lg
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- High conversion of CO2 into cyclic carbonates under solvent free and ambient pressure conditions by a Fe-cyanide complex
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Methods of converting carbon dioxide into valuable chemicals are of great demand but their development is still challenging. Herein, we developed an efficient, green and facile synthetic method for the preparation of a Fe-cyanide complex. The target catalyst showed high catalytic activity for the cyclic reaction of carbon dioxide and epoxide under solvent free conditions and ambient pressure. Meanwhile, the effects of morphology of different catalysts on their catalytic activities were also investigated by the kinetic and thermodynamic studies. In addition, the catalyst could be recycled and reused for at least five successive cycles without significant decrease in the catalytic activity. This target catalyst thus represents one of the efficient and recyclable systems reported for the cyclic reaction in industry.
- Jiang, Pengbo,Ma, Lei,Wang, Kaizhi,Lan, Kai,Zhan, Zhenzhen,Iqbal, Anam,Niu, Fang,Li, Rong
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p. 17211 - 17219
(2019/11/20)
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- Fabrication of double-shelled Fe2O3/CeO2 boxes from CeO2-modified Prussian blue and their enhanced performances for CO removal and water treatment
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Multiple components and well-defined complex nanostructures may synergistically enhance the performance and application of composite materials. Herein, hierarchical double-shelled Fe2O3/CeO2 microboxes, with the robust Fe2O3 hollow microcubes inside and CeO2 shell outside, were fabricated by a facile wet chemical process, which involved the decoration of Fe4[Fe(CN)6]3 microcubes with CeO2 nanoparticles, followed by the thermal decomposition of this precursor in air. The non-equilibrium heat treatment induced heterogeneous contraction process during the calcination of the Fe4[Fe(CN)6]3/CeO2 precursor in air, which is responsible for the formation of the unique hollow structures. The pre-deposited CeO2 nanoparticles acted as stabilizer for the exterior surface of Fe4[Fe(CN)6]3 cubes, and consequently played a crucial role in the formation of the unique hollow structures. The CeO2 molar concentration of the resultant products could be tailored by simply varying the feeding amount of Ce(NO3)3. As a CO oxidation catalyst, the as-prepared Fe2O3/CeO2 microboxes displayed higher catalytic activity in comparison with both CeO2 particles and Fe2O3 cubes owing to the high specific surface area and the synergetic interaction between Fe2O3 and CeO2. More importantly, the catalytic performance is closely associated with the component ratio between Fe2O3 and CeO2. In addition, the Fe2O3/CeO2 microboxes also exhibited significant adsorption capacity of Congo red, implying their potential application in water treatment.
- Liu, Ling,Shi, Jingjing,Wang, Ruiyu,Cao, Hongxia,Liu, Ziwu
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p. 544 - 556
(2017/07/27)
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- Effect of dopant Fe3+ ions on the structure of zinc potassium hexacyanoferrate(II) and the mobility of H2O molecules and K + Ions in its structural channels
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We studied how Fe3+ ion doping affects the structure formation and the state and mobility of H2O molecules and K+ ions in the structure of hexacyanoferrate (Zn-K-HCF) of composition K 2Zn3[Fe(CN)6]2 · xH 2O. We found that Fe3+ ion doping levels up to 7-10 at. % decrease the hexagonal (rhombohedral) unit cell parameters. The doping entails the following effects: isomorphous substitutions of Fe3+ ions for Zn2+ ions at lattice sites, an equivalent decrease in the K + ion concentration, an increase in the H2O concentration, and the strengthening of water bonding with its nearest neighbors in the channels of the structure. The combination of the above factors decreases the electrical K+ ion conductivity of the Zn-K-HCF samples from 1.3 × 10-2 to 2.8 × 10-4 S/m for the doping levels from 0 to 8.7 at. % Fe3+. The Fe3+ ion doping deteriorates the K+ ion mobility and entails a growth in the Cs + ion distribution coefficient in the ion-exchange equilibrium K?+ + Cs+ ? Cs?+ + K +. Copyright
- Khodyashev,Vol'khin
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p. 1455 - 1458
(2008/10/09)
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- Sol-gel processed cerium oxide and mixed cerium-titanium oxide films as passive counter electrodes for transmissive electrochromic devices
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Thin films of CeO2 and mixed oxide CeO2-TiO 2 with a Ce/Ti mole ratio of one have been obtained by an alcohol based sol-gel process. The precursor materials for the latter comprises a Ce(III) salt, CeCl3.7H2O and titanium propoxide in ethanol. The mixed oxide film is characterized by the prevalence of amorphicity, though morphological studies have indicated the presence of CeO2 nanograins. Pure cerium oxide film exhibits crystalline nature with the average grain size in the nanorange. In agreement with the higher levels of Li + ion intercalation in an amorphous film in comparison to crystalline film, a superior inserted/extracted charge in the mixed oxide film is revealed from the electrochemical investigations. The films prepared from an aged sol are observed to exhibit a much higher ion insertion capacity and transparency as compared to the films deposited using as-prepared sol. The ion insertion capacity obtained for an 800 nm thick film of mixed oxide is of the order of 18.36 mC cm-2 at a frequency of 0.0011 Hz. The presence of well-defined grains of about 89 nm dimension in the CeO2-TiO 2 film has been determined by the AFM studies. The measurements on the films for electrochromic applications such as smart windows reveal fast coloration-bleaching kinetics for WO3 in conjunction with the mixed CeO2-TiO2 film and affirm its suitability as passive counter electrode in electrochromic devices.
- Verma, Amita,Samanta,Bakhshi,Agnihotry
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p. 1756 - 1765
(2007/10/03)
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- Direct incorporation of a ferric ion in the porphyrinogen core: Tetrakis(cyclohexyl)iron porphyrinogen anion with different conformers and its reaction with iodine
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Et4N[L″TeIII]·3DCM (1) is directly synthesized by adding ferric chloride into a solution of a lithium salt of tetrakis(cyclohexyl)porphyrinogen (L″). [L″]4- is a good chelating ligand for both Fe(III) and Fe(II) ions. It is an avid proton scavenger but not a reducing agent. 1 showed a magnetic moment (μeff) of 4.3 μB in the solid, which changed to 6.0 μB in solution. This change in spin state is common for all iron porphrinogens. 1 showed polymorphism, and with pyridine in the lattice, it changed to Et4N[L″TeIII]·DCM 0.5Py1.5 (2), possessing two different conformers. Calculation of these conformers at the density functional theory level showed the relative energies of all d orbital changes in three conformers, highlighting the influence of the disposition of a peripheral ligand. Iodine oxidation of 1 yielded [L″γγFeIII][I 3·I2+·I3-] (3) with the introduction of two Cα-Cα bonds with concomitant reduction of Fe(III) to Fe(II). Its μeff (5.4 μB) in the solid changed to 4.8 μB in solution, suggesting a high spin state (S = 2) for Fe(II).
- Bhattacharya, Dibyendu,Dey, Soumen,Maji, Suman,Pal, Kuntal,Sarkar, Sabyasachi
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p. 7699 - 7701
(2008/10/09)
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- Iron Hexacyanoferrate Films : Spectroelectrochemical Distinction and Electrodeposition Sequence of 'Soluble' (K+-containing) and 'Insoluble' (K+-free) Prussian Blue, and Composition Changes in Polyelectrochromic Switching
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Films of Prussian Blue (PB) deposited by electroreduction in the absence of K+ have absorbance maxima at 730 nm which narrow and shift on voltammetric cycling in KCl solution to 690 nm, these absorptions being deemed diagnostic of 'insoluble' and 'soluble' PB respectively.Spectroelectrochemistry shows that the initial deposit even in K+ solution is invariably the insoluble form, being then converted into the soluble, irrespective of electrochemical conditions or solution composition ; this resolves several problems in the current literature.Electrochemical oxidation of PB gives continuous mixed-valence compositions up to complete oxidation; by contrast, reduction to Prussian White involves clean conversion of one into the other at a critical potential.
- Mortimer, Roger J.,Rosseinsky, David R.
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p. 2059 - 2062
(2007/10/02)
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