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Na-ion and K-ion batteries are promising alternatives for large-scale energy storage due to their abundance and low cost. Intercalation of these large ions could cause irreversible structural deformation and partial to complete amorphization in the crystalline electrodes. A lack of understanding of the dynamic changes in the amorphous nanostructure during battery operation is the bottleneck for further developments. Here, we report the utilization of in- operando digital image correlation and XRD techniques to probe dynamic changes in the amorphous phase of iron phosphate during potassium ion intercalation. In- operando XRD demonstrates amorphization in the electrode's nanostructure during the first charge and discharge cycle. Additionally, ex situ HR-TEM further confirms the amorphization after potassium-ion intercalation. An in situ strain analysis detects reversible deformations associated with redox reactions in the amorphous phases. Our approach offers new insights into the mechanism of ion intercalation in the amorphous nanostructure which are highly potent for the development of next-generation batteries.

A polyethyleneimine (PEI)-iron phosphate (FePO4) nanocomposite is prepared by immobilization of PEI onto the surface of FePO4 nanoparticles via electrostatic interaction. The obtained PEI-FePO4 nanocomposites are spherical with a size centered in ca. 100 nm. They provide a novel adsorbent for the solid-phase extraction of DNA from complex sample matrices. At pH 4, 50 μg mL(-1) of DNA (salmon sperm DNA sodium salt) in 1.0 mL aqueous solution are quantitatively adsorbed (100%) by 2mg of the PEI-FePO4 nanocomposites, and meanwhile the coexisting albumin at a same concentration level is not retained, demonstrating the favorable selectivity of the nanocomposites to DNA against proteins. The adsorption behaviors of DNA onto the PEI-FePO4 nanocomposites fit Langmuir model, corresponding to an adsorption capacity of 61.88 mg g(-1). The adsorbed DNA could be readily recovered by using a 0.04 mol L(-1) Britton-Robinson (BR) buffer at pH 10, resulting in a recovery of 85%. The nanocomposites have been further used for the isolation of DNA from a series of real sample matrices, including synthetic λ-DNA sample, human whole blood and Escherichia coli cell lysate. The extraction efficiency and the purity of the recovered DNA are at least comparable to those achieved by using the reported sorbent materials or commercial kits. In addition, the DNAs isolated from human whole blood and E. coli cell lysate are of high quality, which have been further demonstrated by using them as templates for successful PCR amplifications., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In view of the current situation wherein acid resources and valuable components in titanium dioxide waste acid cannot be effectively extracted and are prone to secondary pollution, our research team proposed a new technique consisting of step extraction and the comprehensive utilization of titanium dioxide waste acid. In this paper, the thermodynamics of selective precipitation and the preparation of doped iron phosphate from waste acid were studied. The thermodynamics results show that the content of Al3+, Mn2+, Mg2+, and Ca2+ in the reaction system can be tuned by adjusting the pH during the pre-precipitation process. In the first step, these impurity ions should be settled as much as possible; then, Fe2+ should be oxidized to Fe3+ so as to obtain iron phosphate with higher purity in the next step of the precipitation process. The effects of the reaction temperature, seed crystals, pH value, and P/M on the precipitation process were investigated in detail. The experimental results show that in the reduced state, the optimal precipitation conditions are a temperature of 75 °C, an initial pH value of 4.5, and an optimal P/M molar ratio of 1.1. In the oxidized state, the optimal precipitation conditions are a temperature of 60 °C, a solution pH = 2.5, and a reaction time of 25 min. After calcination, the precipitate mainly consists of iron phosphate, which basically meets the requirements of an iron phosphate precursor. [ABSTRACT FROM AUTHOR]

The purilication and reuse ol titanium dioxide by-product lerrous sullate are ol great signilicance lor improving the added value ol the iron-containing products and the comprehensive utilization of resources. The removal ol manganese and the reuse of iron in titanium dioxide by-product lerrous sullate were studied. The leasibility ol oxidizing Fe2+ to Fe'十 by hydrogen peroxide and oxidizing Mn2+ to Mn02 by potassium permanganate was theoretically analyzed. The effects ol oxidant dosage, pH value ol the solution and reaction time on the removal rate ol manganese were investigated. The experimental results show that the manganese removal rate could reach 99. 9% under the conditions ol KMnO4 dosage 1. 0 times ol the theoretical value, pH value ol 1. 20 and oxide reaction time lor 30 min. The manganese content in the purified ferric sullate solution was reduced to 0. 28 mg/L alter manganese removal treatment The purified solution was used as the iron source to synthesize iron phosphate by liquid-phase precipitation method, and the nanoscale high-purity amorphous iron phosphate dihydrate precursor was obtained, which can be transformed into a-quartz-type iron phosphate alter calcination. [ABSTRACT FROM AUTHOR]

[Display omitted] The high binding affinity of iron(oxyhydr)oxides for phosphate has recently been used in medicine to treat hyperphosphatemia, an abnormally elevated phosphate concentration in the blood. For iron(oxyhydr)oxide nanoparticles, the composition of the organic shell has a more significant influence on their interaction with phosphate than is often assumed. This study shows different mechanisms in phosphate binding, using the example of two similar new phosphate-binding agents. We characterized the phosphate-binding behavior of two iron(oxyhydr)oxide-based nanomaterials with similar composition and particle properties and investigated their binding mechanisms by spectroscopic methods. For the often prescribed Velphoro, we demonstrated a phosphate binding capacity of>210 mg/g. A similar active ingredient named C–PAM binds over 573 mg/g. Spectroscopic measurements highlighted differences in the binding mechanism. While Velphoro binds phosphate via surface complexation independent of pH and adsorbent concentration, C–PAM shows a strong concentration dependence. At low concentrations, phosphate is bound via complexation reactions. The iron(oxyhydr)oxide structure was dissolved at higher phosphate concentrations and formed various iron phosphate species. The substances behave differently upon interaction with phosphate, although being very similar in composition and crystal structure. Thus, we demonstrated a crucial influence of the ligands in the shell on the binding mechanism. [ABSTRACT FROM AUTHOR]

Concurrent stabilization of oxyanions such as antimony (Sb), arsenic (As), and heavy metals including lead (Pb) and manganese (Mn) in contaminated soils is difficult because of their diverse chemical properties. Antimony and As are stabilized by sorption with iron oxides while heavy metals are stabilized by phosphate. Hence, iron phosphate can be used to simultaneously stabilize Sb and Pb. Therefore, this study aimed to evaluate the possibility of simultaneous stabilization of Sb and Pb using iron phosphate. A single and a mixed solution of Sb and Pb were reacted with synthesized iron phosphate. Contaminated soil by Sb, As, Mo, Cr, and Mn was treated with iron phosphate, and bioavailable metal concentrations were evaluated by extracting the soil with 0.05 M ammonium sulfate. In a single solution, Sb(III) and Sb(V) sorption rate ranged up to 97% and 65%, respectively. In a mixed metal solution, Sb sorption increased compared to the single solution and Pb removal reached more than 95% in all cases. The sorption of Sb increased as the pH decreased, but the Sb(III) sorption was less affected by the pH than Sb(V). In various pH ranges, Sb(III) and Sb(V) sorption rates increased by 26 ~ 32% and 38 ~ 68%, respectively, compared to the single solution. Especially, Sb(V) sorption significantly increased in the presence of Pb at lower pH because of the lower solubility of iron phosphate. In soil, iron phosphate slightly decreased bioavailable As, Cr, Mo, Sb, and Mn concentrations. Therefore, metalloids and metals can be simultaneously stabilized by iron phosphate both in solution and soil. [ABSTRACT FROM AUTHOR]

A novel process for the high-value-use of iron from bauxite residue was proposed in this work. The process was trying to use the iron-containing stripping solution generated during resource recycling of bauxite residue to produce battery-grade FePO4·2H2O product. Thermodynamics calculation indicates that Fe and P in the stripping solution mainly existed in the form of FeHPO4+, and the theoretical pH for the conversion reaction from FePO4·2H2O to Fe(OH)3 was 1.72. The optimal condition for the synthesis of FePO4·2H2O using the stripping solution was determined as: reaction pH of 0.8, reaction temperature of 90°C, Fe/P ratio of 1, and reaction time of 24 h. XRD result showed that the synthesized FePO4·2H2O was well-crystallized and perfectly matched with the characteristic peaks of FePO4·2H2O. Moreover, all the parameters of the synthesized iron phosphate meet the quality requirements of battery precursor. [ABSTRACT FROM AUTHOR]

Iron phosphate, Fe2 (HPO4)3*4H2O, is synthesized at ambient temperature, using the inorganic sol–gel method coupled to the microwave route. The experimental conditions for the gelling of Fe (III)-H3PO4 system are previously defined. Potentiometric Time Titration (PTT) and Potentiometric Mass Titration (PMT) investigate the acid–base surface chemistry of obtained phosphate. Variations of surface charge with the contact time, Q a function of T, are examined for time contact varying in the range 0–72 h. The mass suspensions used for this purpose are 0.75, 1.25 and 2.5 g L−1. The point of zero charge (PZC) and isoelectric point (IEP) are defined using the derivative method examining the variations dpH d t = f pH , at lower contact time. A shift is observed for PZC and IEP towards low values that are found to be 2.2 ± 0.2 and 1.8 ± 0.1, respectively. In acidic conditions, the surface charge behavior of synthesized phosphate is dominated by > POH ¯ group which pKa = 2.45 ± 0.15. Q against T titration method is performed for synthesized Fe2 (HPO4)3*4H2O in NaCl electrolytes. The maximal surface charge (Q) is achieved at the low solid suspension. Hence, for m = 0.75 g L−1, Q value of 50 coulombs is carried at μ = 0.1 and pH around 12, while charge value around 22 coulombs is reached in the pH range: 3–10. The effect of activation time, Q and pH on sodium insertion in iron phosphate, were fully evaluated. To determine the optimal conditions of the studied process, mathematical models are used develop response surfaces in order to characterize the most significant sodium interactions according to the variation of the pH, Q, the contact time and the contents of the synthesized material. [ABSTRACT FROM AUTHOR]

Municipal biosolids contain organic and inorganic phosphorus (P) that could be recovered for reuse as P fertilizer. Inorganic P compounds include iron phosphates that precipitate and/or adsorbed phosphate ions as a consequence of soluble iron addition in order not to exceed total phosphorus (TP) emission limits. The inorganic orthophosphate (o-Pi) minerals within biosolids can have low solubilities. One P recovery strategy is to maximize the dissolution of o-Pi from biosolids for reuse. Dissolving iron phosphates in biosolids by adding sodium sulfide was assessed as an o-Pi dissolution strategy. 10 % w/w biosolids slurries with a total phosphorus (TP) of 0.97 ± 0.03 mmol P/dry g were mixed with sulfide/TP (S2−/TP) molar ratios from 0 to 4 for up to 96 h. The maximum o-Pi concentration (48 ± 7 mM, or 42 ± 6 % of TP) was obtained for 4 S2−/TP after 24 h at room temperature (RT). Iron concentrations measured by colorimetry (ferrozine) reduced from 0.6 ± 0.1 mM to less than 0.01 mM (S2−/TP > 1). X-ray diffraction and FTIR suggest that sulfide treatment preferentially dissolved amorphous o-Pi-containing solids, vivianite, and minerals with iron, aluminum, phosphate, sulfate, and other subsitutions. Poorly crystalline erdite (NaFeS 2 ·2H 2 O) was detected in products after S2−/TP treatment ratios ≥ 2. Incubation at RT or 37 °C did not affect the o-Pi concentrations for 0 or 4 S2−/TP over 47 h. Sulfide addition could also increase the risk of construction material corrosion, and reduce the efficiency of P recovery by precipitation. There are disadvantages to using sulfide to dissolve o-Pi from biosolids as a potential P recovery process. [Display omitted] • Sulfide dissolved vivianite, amorphous, and substituted iron phosphates in biosolids. • Increasing sulfide concentration increased orthophosphate dissolution from biosolids. • Erdite (NaFeS 2.2H 2 O) was identified if the sulphide to total P molar ratios were >1. • The maximum phosphate concentration was 48 ± 7 mM for 10% biosolids, 4 S2−/TP, 24 h. • Sodium sulfide addition may not be an effective P-recovery strategy for biosolids. [ABSTRACT FROM AUTHOR]

The preparation and structural characterization of three new iron phosphates with general formula Rb3M3Fe5(PO4)8 (M = Mn, Co, Ni) labeled: I, II and III respectively, are reported. Single crystals X-ray diffraction reveals that these compounds crystallize in an original structure, which adopts the monoclinic system with space group C2/c. The unit cell parameters are: a = 19.945(1) Å; b = 14.935(7); c = 9.995(1) Å; β = 119.10(3)° for I, a = 19.826(1) Å; b = 14.948(1); c = 9.927(1) Å; β = 117.14(1) ° for II and for III a = 19.792(2) Å; b = 14.833(2); c = 9.908(2) Å; β = 119.28(2)°. The structures consist of MO6 and (M,Fe)O6 octahedra, linked through common edges to form [M2(M,Fe)2O16]∞ crossing chains running along the [1 1 2] and [1 − 1 2] directions. These chains are interconnected by the FeO6 octahedra and PO4 tetrahedra, generating a 3D framework with intersecting tunnels where the Rb+ cations are located. This paper report the synthesis and the structural study of three new alkali iron phosphates Rb3M3Fe5(PO4)8 (M = Mn, Co, Ni). A projection of the Rb3M3Fe5(PO4)8 (M = Mn, Co, Ni) structure along the [112] direction. [ABSTRACT FROM AUTHOR]

A comparative study of the activation of n-hexane over 12-molybdophopshoric acid (H3PMo12O40 or HPA), Fe3+ doped HPA (Fe0.69H0.93PMo12O40) and an iron phosphate catalyst (P/Fe = 1.22) was carried out. The Fe doped HPA catalyst is thermally more stable and less acidic than the unmodified HPA catalyst. The HPA and the Fe doped HPA catalysts both catalytically produced 2,5-dimethyltetrahydrofuran and 2,5-hexadione (oxygenates), with the Fe doped HPA catalyst selectively producing more oxygenates than the HPA catalyst. The iron phosphate catalyst produced cis-2-hexene and 1-hexene but no oxygenates, which implies that the iron phosphate catalyst promotes dehydrogenation, but not oxygen insertion. At 360 °C, the HPA catalyst initiated benzene formation reactions. At isoconversion of ca. 8% under isothermal conditions, the iron phosphate catalyst gave the highest selectivity (72%) towards benzene, which may have formed through both catalytic and non-catalytic reactions. In contrast, the Fe doped HPA catalyst showed a lower benzene selectivity than the HPA catalyst with a corresponding increase in cyclic oxygenates. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The development of efficient and earth-abundant electrocatalysts for overall water splitting is important but still challenging. Herein, iron phosphate (FeP i) electrode is synthesized using a successive ionic layer deposition and reaction (SILAR) method on a nickel foam substrate at room temperature and is used as a bifunctional electrocatalyst for water splitting. The prepared FeP i electrodes show excellent electrocatalytic activity and stability for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The FeP i electrode exhibits low overpotential of 230 mV and 157 mV towards the OER and HER, respectively, with superior long-term stability. As a result, an electrolyzer that exploits FeP i as both the anode and the cathode is constructed, which requires a cell potential of 1.67 V to deliver a 10 mA cm−2 current density in 1 M KOH solution. The exceptional features of the catalyst lie in its structure and active metal sites, increasing surface area, accelerated electron transport and promoted reaction kinetics. This study may provide a facile and scalable approach to design a high-efficiency, earth-abundant electrocatalyst for water splitting. [ABSTRACT FROM AUTHOR]

The phosphoric acid addition effect on phosphate insulation coating microstructure was investigated in this study. The relationships between the phosphate insulation coating microstructure and temperature resistance, corrosion resistance and magnetic properties of iron-based soft magnetic composites (SMCs) were studied by using SEM, TEM/EDS and FTIR. It was observed that an iron phosphate/carbonyl iron core/shell structure is formed with carbonyl iron powder after phosphatizing treatment. The iron phosphate phase was identified as amorphous and its thickness increased from 30 nm to 60 nm as the phosphoric acid concentration was increased from 1 wt% to 2 wt%. When the phosphoric acid concentration was further increased to 5 wt%, the excess iron phosphate precipitates between the soft magnetic composite particles. The temperature and corrosion resistance and resistivity of the iron-based SMCs can be effectively improved using carbonyl iron powders after phosphatizing. The initial permeability of the iron-based SMCs decreased with increasing phosphoric acid concentration due to thicker insulation layer formation. However, the imaginary permeability below the domain wall displacement resonance frequency decreased with increasing phosphoric acid concentration. The DC-bias superposition characteristic can also be improved by increasing the phosphoric acid concentration. Iron-based SMCs with superior temperature and corrosion resistance, initial permeability, magnetic loss and DC-bias superposition characteristics can be obtained by controlling the phosphoric acid concentration during phosphatizing to adjust the iron phosphate precipitate thickness on the iron powder surface. [ABSTRACT FROM AUTHOR]

Crystallization behaviour in 10 and 20 mass% BaO-loaded iron phosphate glasses was studied using differential thermal analysis technique under non-isothermal conditions. Activation energy of crystallization was estimated from the experimental data by applying isoconversional method of kinetic analysis. Activation energy of crystallization was found to increase in 10 mass% BaO-loaded iron phosphate glass, whereas the activation energy showed a decreasing trend as a function of fraction of crystallization ( α) in 20 mass% BaO-loaded iron phosphate glass. Fe(PO) was found to be the major product of crystallization in both the BaO-loaded iron phosphate glasses, and other products of crystallization varied depending on the composition of the glass. The concentration of Fe was estimated based on the contribution of various identified products of crystallization and composition of the parent glass. The estimated concentration of Fe ions was 19 and 22% after the heat treatment of 10 and 20 mass% BaO-loaded iron phosphate glasses, respectively. The crystallization behaviour of BaO-loaded iron phosphate glass is compared with iron phosphate glass and iron phosphate glass containing equivalent concentration of CsO. The activation energy of crystallization of BaO-loaded glasses was relatively higher than that of CsO-loaded iron phosphate glass. The results and comparison on crystallization of these glasses are presented in this paper. [ABSTRACT FROM AUTHOR]

Iron hydroxyl phosphate (Fe 3 (PO 4 ) 2 (OH) 2 ) microspheres with diameters of several micrometers have been successfully prepared using Fe(NO 3 ) 3 ·9H 2 O and NaH 2 PO 4 ·2H 2 O in a mixed solvent of deionized water and glycerin by a facile one-step solvothermal method. The crystal phase of the product changes from poorly crystallized FePO 4 ·2H 2 O nanoparticles into well-crystallized Fe 3 (PO 4 ) 2 (OH) 2 microspheres as the amount of glycerin increases. The as-prepared Fe 3 (PO 4 ) 2 (OH) 2 microspheres can transform into FePO 4 through thermal treatment at 800 °C in air. The cytotoxicity tests show that the as-prepared Fe 3 (PO 4 ) 2 (OH) 2 microspheres have good biocompatibility. We expect that the as-prepared Fe 3 (PO 4 ) 2 (OH) 2 microspheres are promising for the applications in various fields. [ABSTRACT FROM AUTHOR]

Iron(III)-precipitates formed by Fe(II) oxidation in aqueous solutions affect the cycling and impact of Fe and other co-precipitated elements in environmental systems. Fresh Fe(III)-precipitates are metastable and their transformation into more stable phases during aging may result in the release of initially co-precipitated ions. Phosphate, silicate, Mg and Ca play key roles in determining the structure and composition of fresh Fe(III)-precipitates. Here we examine how these ions affect the structure and phosphate retention of Fe(III)-precipitates formed by oxidation of 0.5 mM dissolved Fe(II) at pH 7.0 after aging for 30 days at 40 °C. Iron K-edge X-ray absorption spectroscopy (XAS) shows that aged precipitates consist of the same structural units as fresh precipitates: Amorphous Fe(III)- or Ca-Fe(III)-phosphate, ferrihydrite, and poorly crystalline lepidocrocite. Mg, Ca, and dissolved phosphate stabilize (Ca-)Fe(III)-phosphate against transformation into ferrihydrite. Silicate further attenuates (Ca-)Fe(III)-phosphate transformation. The crystallinity of lepidocrocite formed in phosphate- and silicate-free solutions slightly increases during aging. The transformation of Fe(III)- and Ca-Fe(III)-phosphate into ferrihydrite and ongoing ferrihydrite crystallization during aging result in the release of co-precipitated phosphate. Dissolved Ca on the other hand limits phosphate concentrations to values consistent with solubility control by octacalciumphosphate. Owing to the combined effects of Ca and silicate, phosphate is most effectively retained by Fe(III)-precipitates formed and aged in Ca- and silicate-containing solutions. The results from this study contribute to an improved understanding of the formation and transformation of Fe(III)-precipitates and emphasize that the complexity of Fe(III)-precipitate dynamics in the presence of multiple interfering solutes must be considered when addressing their impact on major and trace elements in environmental systems. [ABSTRACT FROM AUTHOR]

The presence of iron in pregnant leach solutions presents significant processing challenges. The removal of iron impurities from leach solutions by means of iron phosphate precipitation may be a feasible alternative to more conventional iron oxide/iron hydroxide precipitation processes. This study compares the performance of the iron phosphate precipitation process with that of the hematite process at different operating temperatures (40 °C–90 °C), pH conditions (pH 1–pH 3) and seeding measures for the removal of iron from a chloride leach solution. The extent of iron removal, co-precipitation of nickel and copper, and solid-liquid separation were used as performance criteria for the comparison. Seeded iron phosphate precipitation at pH 1 and 40 °C resulted in 98.8% iron removal with 0.5% nickel and 2.8% copper losses. 99.8% iron removal was achieved with the iron phosphate precipitation process at pH 1 and 80 °C, but the nickel and copper losses increased to 8.7% and 20.8%, respectively, with the increase in temperature. Seeded hematite precipitation at pH 1 and 80 °C yielded 99.6% iron removal with 3.5% nickel and 1.7% copper losses. For the hematite process, nickel and copper losses decreased with an increase in temperature. Increasing the pH yielded higher nickel and copper losses for both processes. All seeded precipitation experiments produced easily filterable precipitates. Unseeded iron phosphate precipitates produced at 40 °C and pH 1 were filterable, but increased nickel and copper losses were observed. Unseeded hematite precipitation resulted in high nickel and copper losses, with the precipitates practically impossible to filter. Iron phosphate precipitates exhibited more favourable settling characteristics than the precipitate produced with the hematite process. [ABSTRACT FROM AUTHOR]

A new iron phosphate, rubidium zinc iron(III) phosphate, RbZnFe(PO4)2, has been synthesized as single crystals by the flux method. This compound is isostructural to the previously reported KCoAl(PO4)2 [Chen et al. (1997). Acta Cry st. C53,1754-1756]. Its structure consists of a three-dimensional framework built up from corner-sharing PO4 and (Zn,Fe)O4 tetrahedra. This mode of linkage forms channels parallel to the [100], [010] and [001] directions in which the Rb+ ions are located. [ABSTRACT FROM AUTHOR]

An iron phosphate catalyst prepared using the ammonia gel method was supported on silica (CAT 1) and a commercial iron phosphate catalyst was supported on silica using the wet impregnation method (CAT 2). The XRD patterns of both the catalysts showed the presence of quartz-like iron phosphate and a tridymite like phase. In situ XRD under a reducing environment and TPR showed the formation of iron pyrophosphate for both the catalysts at 500 °C. The Mössbauer spectra of the catalysts were similar and showed the presence of the ferric ion only. NH-TPD revealed the presence of Lewis and Brønsted acidic sites on both the catalysts. Oxidative dehydrogenation reactions of methyl iso-burate (MIB) were carried out using a continuous flow fixed bed reactor at contact times of 0.4 and 0.8 s. The conversion of MIB was marginally higher at a contact time of 0.8 s. CAT 2 gave an 11 % yield of methyl methacryalate (MMA) compared to 21 % over CAT 1 at a contact time of 0.8 s. The conversion of MIB increased with co-feeding water. A maximum conversion of MIB (82 %) was obtained at 400 °C, giving a yield of 20 % MMA at a contact time of 0.8 s over CAT 1. However, co-feeding water increased the hydrolysis reaction also, which increased the yield towards iso-butyric acid and methacrylic acid. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Arion vulgaris is one of the most important slug pests of crop plants, and is extremely hard to control. We assessed the effectiveness of a slug pellets containing iron phosphate, compared with methiocarb- and metaldehyde-based molluscicides, and of the parasitic nematode P. hermaphrodita contained in the commercial bioproduct Nemaslug. The effect of various doses of these substances and the nematode in reducing slug damage to Chinese cabbage plants was evaluated in laboratory experiments. A reduction in slug numbers and plant damage was obtained following application of the molluscicides, and a reduction in plant damage following application of P. hermaphrodita (immersion of plant roots in the nematode-containing liquid). The results are of great practical significance, because they show that it is possible to reduce the recommended dose of iron phosphate (5 g/m2) by one half. Another important finding is that application of the nematode in the form of root immersion is more effective than spraying. The study demonstrates the usefulness of the nematode and of the iron phosphate molluscicide in protecting plants from A. vulgaris; this is of particular importance for crops on which the application of traditional molluscicides is not possible. [ABSTRACT FROM AUTHOR]

Three kinds of bulk iron phosphates were prepared via different methods and employed as model catalysts in the oxy-bromination of methane (OBM). NaFe(PO) was obtained via a fluoride route for the first time that showed even superior catalytic performance than FePO. Phase evolution from NaFe(PO) to NaFe(PO) after the OBM was confirmed both by X-ray diffraction and Fe Mössbauer spectroscopy. Temperature-programmed reduction of hydrogen and desorption of CHBr revealed that the redox capacity of iron phosphates were responsible for the generation of bromine radicals on catalyst surfaces while CHBr-involved reactions likely belonged to gas-phase reactions. Graphical Abstract: Model iron phosphate catalysts were synthesized by three different methods. It was found that the NaFe(PO) catalyst prepared by a fluoride route showed superior OBM performance than the other two catalysts both with the phase of FePO, especially for producing higher CHBr selectivity.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: A significant gap in our knowledge of phosphate crystal chemistry is the lack of understanding of what controls the depolymerization of [PO4] tetrahedra. A new route using phosphoric acid without any added water at 240°C has been developed to synthesize two new compounds Ba2Fe2[H(PO3OH)2][H(P2O7)2] and Ba2Fe[H(P2O7)2], as well as a new polymorph β-BaFe2(P2O7)2 from annealing the former at ≥500°C. Structural characterizations show that Ba2Fe2[H(PO3OH)2][H(P2O7)2] features a novel 2D 2 ∞{[Fe2[H(PO3OH)2][H(P2O7)2]]4−} layer structure containing both hydrogen-diphosphate [H(P2O7)2] and hydrogen-monophosphate [H(PO3OH)2] groups, whereas Ba2Fe[H(P2O7)2] and β-BaFe2(P2O7)2 possess an 1D chain structure and a 3D framework structure, respectively. These structures support a control of hydrogen on the depolymerization of [PO4] groups and our work opens a new way for the synthesis of other novel phosphates using controlled water activities. [Copyright &y& Elsevier]

Highlights: [•] Mesoporous iron phosphate is prepared by a cationic surfactant-assisted procedure. [•] Up to 30% of phosphonate units can enter the oxo-phosphate network in hybrid solids. [•] Pure and functionalized materials exhibit relatively high surface areas. [ABSTRACT FROM AUTHOR]

Chemical lithiation of amorphous FePO with LiI in acetonitrile is performed to form amorphous LiFePO. The amorphous FePO·2HO precursor is synthesized by co-precipitation method from equimolar aqueous solutions of FeSO·7HO and NHHPO, using HO (hydrogen peroxide) as the oxidizing agent. The nanocrystalline LiFePO/C is obtained by annealing the amorphous LiFePO and in situ carbon coating with sucrose in a reducing atmosphere. The particle size of FePO·2HO precursor decreases with increasing reaction temperature. The final LiFePO/C products completely maintain the shape and size of the precursor even after annealing at 700 °C for 2 h. The excellent electrochemical properties of these nanocrystalline LiFePO/C composites suggest that to decrease the particle size of LiFePO is very effective in enhancing the rate capability and cycle performance. The specific discharge capacities of LiFePO/C obtained from the FePO·2HO precursor synthesized at 75 °C are 151.8 and 133.5 mAh g at 0.1 and 1 C rates, with a low capacity fading of about 0.075 % per cycle over 50 cycles at 0.5 C rate. [ABSTRACT FROM AUTHOR]

Abstract: FePO4-SBA-15 (OP) was directly synthesized via a one-pot hydrothermal technique, using Fe(NO3)3 and H3PO4 as the precursors. FePO4/SBA-15 (IMP) was also prepared as a reference, using an impregnation method and commercially available SBA-15 as the support. The yielding samples were employed to catalyze the harsh oxy-bromination of methane (OBM) reaction, showing similar initial catalytic performances. The fresh and spent samples after catalytic reaction were thoroughly characterized by N2-physisoption, inductively coupled plasma, wide- and small-angle X-ray diffraction, transmission electron microscopy, diffuse reflectance UV–vis spectroscopy, temperature-programmed oxidation, and room temperature 57Fe Mössbauer spectroscopy. It was found that the FePO4 was in good crystalline in the OP sample while it was in amorphous for the IMP catalyst. Despite this difference, both FePO4 phases in the fresh samples were transformed into Fe7(PO4)6 and Fe2P2O7 in the spent ones. Furthermore, the OP catalyst showed excellent stability in a period of 1000h time-on-stream performance without apparent deposition of cokes. The losses of P and Fe after the catalytic evaluation were only 9.5% and 15.5%, respectively, while the ratio of P/Fe remained close to 1.0. N2-adsorption and TEM observations confirmed that the mesoporous pores were extremely stable under the harsh reaction ambience, which might play a crucial role in the stability test. [Copyright &y& Elsevier]

Abstract: By reaction between synthetic phosphosiderite FePO4·2H2O, urea (NH2)2CO, and acetone (CH3)2CO, we report a novel solvothermal synthesis of polycrystalline NH4FePO4·H2O. The preparation of other two individual phases, NH4Fe2(OH)(PO4)2·2H2O and NH4Fe2(PO4)2, is also described. The obtained product is a function of the reaction time and the N/P molar ratio in the reagent mixture, and the existence of structural memory in the dissolution–precipitation processes is discussed. Below 25K, NH4FePO4·H2O behaves magnetically in a complex way, because both ferromagnetic and antiferromagnetic signals are superimposed, suggesting the existence of a canting of iron(II) magnetic moments. [Copyright &y& Elsevier]

Abstract: Unique amorphous FePO4 with particle size ranging from 20 to 80nm has been successfully synthesized by a new cost-effective electrochemical method. This FePO4 possesses a mesoporous structure with specific surface area of 65.2m2 g−1 and dominant pore diameter of 23.6nm. The basic formation mechanism has been discussed. These amorphous mesoporous FePO4 nanoparticles can be used as precursors to prepare LiFePO4/C nanocrystals with porous structure. The obtained LiFePO4/C cathode materials exhibit excellent cycling performances. At a 0.5C rate, the discharge capability is above 140.0mAhg−1 and the capacity retention rate is higher than 98% after 50 cycles. The microstructural and electrochemical analyses reveal that these amorphous mesoporous FePO4 nanoparticles are the perfect precursors to prepare LiFePO4/C composite. Furthermore, this facile, cost-effective and green electrochemical strategy can be easily scaled up for commercialization, and also could open avenues towards synthesizing other mesoporous phosphate materials. [Copyright &y& Elsevier]

Abstract: Choline, as a marker of cholinergic activity in brain tissue, is very important in biological and clinical analysis, especially in the clinical detection of the neurodegenerative disorders disease. This work presents an electrochemical approach for the detection of choline based on prussian blue modified iron phosphate nanostructures (PB–FePO4). The obtained nanostructures showed a good catalysis toward the electroreduction of H2O2, and an amperometric choline biosensor was developed by immobilizing choline oxidase on the PB–FePO4 nanostructures. The biosensor exhibited a rapid response (ca. 2s), low detection limit (0.4±0.05μM), wide linear range (2μM to 3.2mM), high sensitivity (∼75.2μAmM−1 cm−2), as well as good stability and repeatability. In addition, the common interfering species, such as ascorbic acid, uric acid and 4-acetamidophenol did not cause obvious interference due to the low detection potential (−0.05V versus saturated calomel electrode). This nanostructure could be used as a promise platform for the construction of other oxidase-based biosensors. [Copyright &y& Elsevier]

The iron-manganese phosphate of composition (FeMn)(PO).2HO has been obtained as a single-phase product using hydrothermal methods and the structure has been determined by single crystal X-ray diffraction. The title compound is orthorhombic, Pbca, a = 8.720(1), b = 9.884(1), c = 10.114(2) Å, isostructural with strengite. The structure consists of a linkage of MO octahedra and PO tetrahedra. The octahedra are insular and are held together to form a three-dimensional structure by the tetrahedra. The crystal structure study revealed that (FeMn)(PO)⋅2HO exhibits a strong Jahn-Teller effect. The compound has been characterized by Raman and IR Spectroscopy, showing the bonds characteristic of the PO polyanions. Measurements by the electric permittivity revealed a peak at 350 K. Graphical Abstract: The iron-manganese phosphate of composition (FeMn)(PO)⋅2HO has been obtained as a single-phase product using hydrothermal methods and the structure has been determined by single crystal X-ray diffraction. The title compound is orthorhombic, Pbca, a = 8.720(1), b = 9.884(1), c = 10.114(2) Å, isostructural with strengite. The structure consists of a linkage of MO octahedra and PO tetrahedra. The octahedra are insular and are held together to form a three-dimensional structure by the tetrahedra. The crystal structure study revealed that (FeMn)(PO)⋅2HO exhibits a strong Jahn-Teller effect. The compound has been characterized by Raman and IR Spectroscopy, showing the bonds characteristic of the PO polyanions. Measurements by the electric permittivity revealed a peak at 350 K.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Phosphorus is absorbed by the plants as orthophosphate anions (HPO42- and H2PO4-). The concentration of soluble phosphate in soil is low and it must be supplemented from other sources. Some of the bacteria with phosphate solubilising capacity are able to transform the accumulated insoluble phosphates in the soil into soluble forms, making them available for plants. Our aim was to assay phosphorus mobilization from different inorganic phosphates (calcium and iron phosphate, hydroxyapatite) by bacteria isolated from rhizospheric soil proposed for biofertilizer production. [ABSTRACT FROM AUTHOR]

Single crystals of iron and manganese phosphate Fe 6.36Mn 0.64(PO 3(OH)) 4(PO 4) 2 was synthesized by hydrothermal method. The compound crystallizes in the Fe 7(PO 4) 6 structure type and is isotypic with the solid solution $$ {\text{M}}_{{7 - {\text{x}}}} {\text{M}}_{\text{x}}^{\prime} \left( {{\text{HPO}}_{4} } \right)_{4} \left( {{\text{PO}}_{4} } \right)_{2} $$ where M is Fe, Co, Mg, Mn. The compound is triclinic, P-1, a = 6.571(5), b = 7.993(3), c = 9.547(2) Ǻ, α = 103.97(1)°, β = 109.29(2)°, γ = 101.57(3)°. The structure is based on a three-dimensional framework of distorted edge-sharing MO 6 and MO 5 polyhedra, forming infinite chains, which are interlinked by corner-sharing with PO 4 tetrahedra. The formula unit is centrosymmetric, with all atoms in general positions except for one Fe atom, which has site symmetry −1. Graphical Abstract:: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: A new iron phosphate (NH4)4Fe3(OH)2F2[H3(PO4)4] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P21 /n (No. 14), a=6.2614(13)Å, b=9.844(2)Å, c=14.271(3)Å, β=92.11(1)°, V=879.0(3)Å3). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO4) groups to form ten-membered-ring channels along [100]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO4)3(OH)2F2], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic exchange below T N=17K, consistent with superexchange interactions expected for the linear trimer of ferric octahedra with the Fe–F–Fe angle of 132.5°. [ABSTRACT FROM AUTHOR]

Single crystals of iron and manganese phosphate Fe 6.36Mn 0.64(PO 3(OH)) 4(PO 4) 2 was synthesized by hydrothermal method. The compound crystallizes in the Fe 7(PO 4) 6 structure type and is isotypic with the solid solution $$ {\text{M}}_{{7 - {\text{x}}}} {\text{M}}_{\text{x}}^{\prime} \left( {{\text{HPO}}_{4} } \right)_{4} \left( {{\text{PO}}_{4} } \right)_{2} $$ where M is Fe, Co, Mg, Mn. The compound is triclinic, P-1, a = 6.571(5), b = 7.993(3), c = 9.547(2) Ǻ, α = 103.97(1)°, β = 109.29(2)°, γ = 101.57(3)°. The structure is based on a three-dimensional framework of distorted edge-sharing MO 6 and MO 5 polyhedra, forming infinite chains, which are interlinked by corner-sharing with PO 4 tetrahedra. The formula unit is centrosymmetric, with all atoms in general positions except for one Fe atom, which has site symmetry −1. Graphical Abstract:: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: The hydrothermal synthesis and structure for a new iron phosphate based open-framework solid, (NH4)[Fe2(OH)(H2O)(PO4)2]·1.5H2O, is presented. The three-dimensional (3-D) framework is built from butterfly-shaped tetranuclear iron-oxygen clusters, which are coordinated by eight PO4 tetrahedra to create 8-membered windows along the a-, b- and c-axes; the lattice water molecules as well as the counter NH4 + cations reside in the cross channels. The new open-framework solid is a pseudo-polymorph with the known structure of the mineral sphenicidite, and exhibits spontaneous magnetization in the low temperature regime with T N ≈ 25 K, which is a result of canted spin antiferromagnetism. [ABSTRACT FROM AUTHOR]

Abstract: Synthesis, single crystal X-ray diffraction, Mössbauer and magnetic studies of a new iron phosphate Rb9Fe7(PO4)10 are described. This compound crystallizes in the monoclinic system with the space group P21/a and the following parameters: a =9.886(4)Å, b =16.493(2)Å, c =13.437(2)Å, β =110.49(3)° and Z =2. Its structure is closely related to that of the Cs9−x K x Fe7(PO4)10 phosphates. The 3D framework consists of FeO6 and FeO5 polyhedra and Fe2O10 units of corner-sharing FeO6 and FeO5 polyhedra. These units are linked to each other by the phosphate tetrahedra in such a way that the resulting framework forms large intersecting tunnels extending along the a and c directions, where the Rb+ cations are located. A high temperature X-ray powder diffraction study showed a partial decomposition of the product above 773K. The magnetic susceptibility results are consistent with Fe(III) showing an antiferromagnetic ordering below T N ≈19K and a paramagnetic behavior in the range of 50–300K. The application of the Curie–Weiss law yields an effective moment of 5.99μB in a good agreement with the ideal spin only value of 5.92μB for d5-iron(III). The distribution of iron and its local environments were confirmed by a Mössbauer study undertaken at 293 and 4.2K. [Copyright &y& Elsevier]

Abstract: FePO4/SiO2 was employed for the oxidative bromination of methane (OMB) for the first time. A methane conversion of 50% and total selectivity of 96% for CH3Br plus CO (CH3Br:CO≈1) were obtained at 570°C. Comparison experiments were designed to investigate the roles of O2, HBr and the catalysts. Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and 57Fe Mössbauer spectroscopic studies were conducted on the catalysts. It was confirmed that the FePO4 components of the fresh catalyst transformed quickly to stable active species during the induction period, and the active components of the stable catalyst have been found to consist of near-equimolar α-Fe3(P2O7)2 and Fe2P2O7. The reaction over the FePO4/SiO2 catalyst was proposed to follow a redox route based on the results of comparison experiments and associated characterization. [Copyright &y& Elsevier]

Abstract: A new iron phosphate, KMgFe(PO4)2 has been synthesized and investigated by X-ray diffraction, Mössbauer spectroscopy and ionic conductivity. This compound crystallizes in the monoclinic space group C2/c with the parameters a =18.529(7)Å, b =5.402(3)Å, c =9.374(9)Å, β =120.64(5)° and Z =4. Its original structure can be described as the stacking along the [101] direction of [MgFe(PO4)− 2]∞ layers of corner-sharing MO4 (M=0.5 Fe+0.5Mg) and PO4 tetrahedra. The K+ ions are occupying the inter-layer space. The Mössbauer spectroscopy confirms the occurrence of only tetrahedral Fe3+ ions and gives a definitive proof of the disordered character of their distribution. Ionic conductivity results obtained by the impedance spectroscopy technique show that this material is a two-dimensional ionic conductor, with low activation energy, 0.51eV, that is interpreted on the basis of two-dimensional pathways. [Copyright &y& Elsevier]

Abstract: In situ FTIR spectroscopy coupled with downstream mass spectrometry has been used to clarify the pathways for room temperature (rt) CO oxidation over iron phosphate-supported Au catalyst. The charge state of Au on Au/FePO4 after calcination, reduction, or under reaction conditions was assessed by both FTIR spectroscopy (CO probing) and X-ray absorption near edge spectroscopy (XANES). Results from both approaches show that cationic gold species dominate the surface after pretreatment in O2 at 200°C. A portion of the cationic gold on Au/FePO4 can be reduced by the initial CO adsorption at rt, and subsequently repeated CO exposures do not reduce the remaining cationic Au. FTIR and Raman results from cycled CO reduction and O2 reoxidation of Au/FePO4 indicate that there are active structural oxygen species on the surface of Au/FePO4that can be consumed by CO and then replenished by gaseous O2 at rt. Au activates both CO and O2 so that the FePO4 support can undergo reduction (by CO) and reoxidation (by O2) cycles. The results of CO oxidation with labeled 18O2 suggest the operation of two parallel reaction pathways at rt: (1) a redox pathway in which FePO4 supplies active oxygen and (2) a direct pathway on metallic Au, via either Langmuir–Hinshelwood or Eley–Rideal mechanism, in which gas phase O2 provides the active oxygen. [Copyright &y& Elsevier]

Abstract: Slugs are suppressed by cereal flour-based baits or pellets containing metaldehyde, or containing iron phosphate plus chelating agents, which are also consumed by earthworms and other invertebrates. These studies compared the effects of metaldehyde and iron phosphate alone, with those of iron phosphate plus chelating agents EDDS and EDTA, and of the chelating agents alone on earthworms. OECD artificial soil test: Earthworms (Eisenia fetida) were exposed directly to the molluscicides in artificial soil. The test chemicals were: metaldehyde; iron phosphate; ethyldiaminetetraceticacid (EDTA), ethylenediaminesuccinicacid (EDDS) and mixtures of iron phosphate and these latter two chemicals. LD50 values were more than 10,000 mg kg−1 for metaldehyde and iron phosphate, 156.5 mg kg−1 for EDTA, 145.6 mg kg−1 for EDDS, 72.2 mg kg−1 for iron phosphate/EDTA, and 83.0 mg kg−1 for iron phosphate/EDDS. Microcosm test: Four mature Lumbricus terrestris were exposed in each microcosm (15 cm diam. × 30 cm deep) to pellets containing: no active ingredient; metaldehyde (4%); iron phosphate/EDTA (1%) (Sluggo®); iron phosphate (3%); EDTA (3%); EDDS (3%). Metaldehyde and iron phosphate did not affect earthworm feeding, growth or mortality. Sluggo® decreased earthworm feeding and caused loss of weight and mortality. Earthworms consumed fewer pellets containing EDDS or EDTA and lost weight. [Copyright &y& Elsevier]

Abstract: Iron phenyl phosphate (FePP) was synthesized from a mixture of FeCl3 and phenyl phosphate (C6H5PO4H2) in aqueous media. X-ray diffraction (XRD) pattern of the FePP exhibited a peak at 2θ =5.6° and a broad hump at 2θ =15–35°. The FePP was plate-like particles and gave rise to the lattice patterns having uniform alternating spacings of ca. 1.5nm and ca. 1.2nm. The chemical formula of FePP could be shown as Fe(OH)(C6H5PO4H)1.6(H2PO4)0.4·5.1H2O. These facts allow us to infer that the FePP was composed of a multilayer alternating bilayer of phenyl groups and amorphous iron phosphate phases. The synthetic FePP particle was aged at pH 6.0 and 85°C for different periods of 0–120h in aqueous media. Aging for 96h disappeared the FePP and formed monoclinic FePO4·2H2O. Further, the monoclinic FePO4·2H2O transformed in orthorhombic FePO4·2H2O by aging for 120h. The orthorhombic FePO4·2H2O was rod-shaped particles with the size of ca. 18nm in width and ca. 45nm in length and its specific surface area was 25m2 g−1. From these results, it can be presumed that the FePP is dissolved, hydrolyzed and reprecipitated to crystalline FePO4·2H2O. [Copyright &y& Elsevier]

[Display omitted] • A novel iron phosphate (Fe y P z -10) was synthesized by a two-step approach. • The synthesized method of Fe y P z -10 was simple and repeatable. • Fe y P z -10 exhibited the superior U(VI) adsorption capacity than Fe 3 O 4 and FePO 4 ٠2H 2 O. • The adsorption mechanism of Fe y P z -10 for U(VI) uptake was proposed. By combining phosphoric acid precursor synthesis and co-precipitation method, we developed a facile approach for synthesizing iron phosphate (Fe y P z) with repeatable technique and low economic cost. The procedure begins with synthesis of P-doped carbon dot (pCD), followed by introducing the pCD in the preparation condition of Fe 3 O 4. Interesting, the uranium(U(VI)) adsorption capacity of Fe y P z is significantly influenced by the synthesis conditions of Fe y P z and the optimized performance can be achieved by tuning the functional groups and structure of Fe y P z. Compared to the FePO 4 ٠2H 2 O and Fe 3 O 4 , the Fe y P z -10 showed 3561% and 684.5% enhanced performance in U(VI) uptake, respectively. The maximum adsorption capacity of Fe y P z -10 based on Langmuir model could reach up to 1.22 mmol g−1 at pH 4.5, which was comparable with the saturated adsorption capacity based on Thomas model with its value of 0.87 mmol g−1, that was higher than some of adsorbents reported previously. In addition, the adsorbent had a superior reusability and still kept up high adsorption capacity for U(VI) after 5th cycle. Moreover, an adsorption-reduction mechanism was proposed and XPS analysis confirmed the outstanding adsorption capacity for U(VI) on the adsorbent was mainly ascribed to the transformation of Fe2+ to Fe3+ on Fe y P z -10 that results in U(VI) reduction. [ABSTRACT FROM AUTHOR]

Abstract: Vanadium-doped iron phosphates (with 1, 3 and 5wt.% V) were prepared and characterized by XRD, FTIR, UV-DRS, TPR, TEM, Laser Raman, XPS, and potentiometric titration techniques. Both undoped and V-doped catalysts displayed predominant formation of quartz type iron phosphate. In addition, the V-doped catalysts indicated formation of two more phases: V2O5 and (VO)2P2O7. The nitrile yield of V-doped catalysts in the ammoxidation of methyl pyrazine to cyanopyrazine were found to be higher than the yield of bulk FePO4, V2O5 and (VO)2P2O7. The increase in the redox property of the catalyst, as obtained by benzyl alcohol oxidation to benzaldehyde, was found to be the reason for enhanced activity. The variation of V-content in FePO4 revealed that the catalyst reached its optimum activity at 3wt.% V. However, the acid strength of the V-doped catalysts decreased with V-content and this reflected in their cyanopyrazine selectivity. [Copyright &y& Elsevier]