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The potential shortage of mineral phosphorus (P) sources and the shift towards a circular economy motivates the introduction of new forms of P fertilizers in agriculture. However, the solubility of P in new fertilizers as well as their availability to plants may be low. In this experiment, we incubated an agricultural soil poor in P (28 mg P2O5 kg-1) for 63 days in the presence of a range of organic and inorganic poorly soluble P forms commonly found in new fertilizers: hydroxyapatite (P-Ca), iron phosphate (P-Fe), phytic acid (P-Org) and a combination of P-Ca and P-Org (P-Mix). Cellulose and potassium nitrate (KNO3) were added to stimulate microbial activity at the beginning of the incubation. We included a positive control with triple superphosphate (TSP) and negative controls with no P application (with and without cellulose and KNO3). We assessed the fate of the different poorly soluble P forms in NaHCO3 extracts (Olsen P) over time as a proxy for plant-available P. Soil microbial biomass, fungal to bacterial ratio, soil respiration, enzymatic activities (ß-glucosidase, arylamidase and acid and alkaline phosphatase), N mineralization and soil pH were also monitored. At the beginning of the incubation, TSP showed the highest Olsen P across all treatments and P-Fe showed higher levels of Olsen P than the other poorly soluble P forms (p < .05). During the incubation, the levels of Olsen P decreased over time for TSP (positive control). Contrastingly, Olsen P increased significantly over time for all the poorly soluble P forms and the negative controls, indicating an increase in plant-available P. Particularly, levels of Olsen P for the P-Org treatment roughly doubled (shifting from 16.5 mg kg-1 to 32.9 mg kg-1) over the whole incubation period. The rate of increase in Olsen P was positively correlated with microbial biomass C:P ratio (p < .01) for all poorly soluble treatments. The higher levels of Olsen P for the P-Org treatment were also explained by a positive correlation with fungal biomass. Our results show that poorly soluble forms of P may be made available to plants under the influence of the microbial community, with a stronger effect on organic P forms. [ABSTRACT FROM AUTHOR]

A highly organized hexagonal mesoporous iron phosphate framework structure with the designation HMI‐41 was successfully synthesized for the first‐time in a reproducible way using imidazolium‐based ionic liquid as structure directing agent. The unique templating properties of ionic liquid generated a highly ordered well‐crystallized mesoporous matrix having high surface area (445 m2 g−1), thicker pore wall (2.1 nm) and narrow pore size distribution (3.1 nm). The presence of active sites within a tetrahedral framework structure made the novel HMI‐41 catalyst highly effective for phenol hydroxylation in an acidic medium with hydrogen peroxide as the oxidant. The catalyst exhibited outstanding performance, achieving an impressive 80% hydroquinone selectivity and 21% phenol conversion with a hydroquinone‐to‐catechol ratio of seven, which is the highest value ever reported. [ABSTRACT FROM AUTHOR]

Batteries made of charge carriers from Earth‐crust abundant materials (e.g., Na, K, and Mg) have received extensive attention as an alternative to Li‐ion batteries for grid storage. However, a lack of understanding of the behavior of these larger ions in the electrode materials hinders the development of electrode structures suitable for these large ions. In this study, we investigate the impact of alkali ions (Li, Na, and K) on the redox chemistry and mechanical deformations of iron phosphate composite cathodes by using electrochemical techniques and in situ digital image correlation. Na‐ion and Li‐ion intercalation demonstrate a nearly linear correlation between electrochemical strains and the state of charge and discharge. The strain development shows nonlinear dependance on the state of charge and discharge for K ions. Strain rate calculations show that K ion intercalation results in a progressive increase in the strain rate for all cycles. Li and Na intercalation induce nearly constant strain rates with the exception of the first discharge cycle of Na intercalation. When the same amount of ions are inserted into the electrode, the electrode shows the lowest strain generation upon Li intercalation compared to larger alkali ions. Na and K ions induce similar volumetric changes in the electrode when the state of charge and discharge is around 30%. Although the electrode experiences larger absolute strain generation at the end of the discharge cycles upon Na intercalation, strain rates were found to be greater for K ions. Potential‐dependent behaviors also demonstrate more sluggish redox reactions during K intercalation, compared to Li and Na. Our quantitative analysis suggests that the strain rate, rather than the absolute value of strain, is the critical factor in amorphization of the crystalline electrode. [ABSTRACT FROM AUTHOR]

A bifunctional and high‐efficiency solid acid catalyst(S‐SBC) was prepared from papermaking sludge by calcining and sulfonation with concentrated sulfuric acid. The monoclinic FePO4 was added to assist S‐SBC to improve HMF yield. The structure characterization of S‐SBC and its catalytic performance for 5‐hydroxymethylfurfural(HMF) preparation from fructose, glucose and cellulose were investigated. Metal ions and −SO3H in the S‐SBC had synergistic effects on the HMF yield. The HMF yield from fructose, glucose and cellulose were respectively 90.3 %, 73.7 % and 28.8 % with S‐SBC alone. The combination of monoclinic FePO4 and S‐SBC could effectively improve the yield of HMF from glucose and cellulose. The highest yield of HMF from glucose and cellulose were respectively 89.5 % and 53.3 % with the binary catalysts. The mechanism of the synergistic action of the binary catalysts was proposed. Bronsted acid from metal ions hydrolysis and ‐SO3H, ‐COOH, ‐OH grafted on the surface of biochar promoted hydrolysis of cellulose to glucose, which was then coordinated with Lewis acids and isomerized to fructose. Finally, HMF was obtained by dehydrating from fructose. [ABSTRACT FROM AUTHOR]

Many physical and chemical properties of Na+ are very similar to those of Li+, and therefore, some electrode materials for lithium‐ion batteries can also work with sodium ions. As the Na+ ion is larger than Li+, the strains in the host lattice are larger, which can cause deviations in the electrochemical reactions. Herein, mechanical stresses are compared, which are measured by the in situ substrate curvature method during (de)lithiation/(de)sodiation of an FePO4 electrode. The (de)lithiation and (de)sodiation experiments are performed on the same electrode. According to the change of the lattice parameters, during electrode operation, NaxFePO4 particles experience a volume change that is 2.6 times larger than that of LixFePO4. In the measurements, the composite electrode exhibits a change of the stress amplitude between operation with Li and Na by roughly one order of magnitude for 0 < x < 1. Compared with Li+, the mechanical stress evolution during extraction and insertion of Na+ is highly asymmetric. The observed asymmetry in the electrochemical and the mechanical data may be explained by the different energies that are required to move an intermediary amorphous phase away from or toward the crystalline sodium‐rich regions during the (de)sodiation of NaFePO4. [ABSTRACT FROM AUTHOR]

The penultimate aim of all analytical techniques is to provide best quantitative information with high sensitivity and accuracy. Such techniques then can be ideal to estimate the concentration of different species in a sample or to measure the surface concentration and so on. The preliminary step involved in quantitative analysis is evaluation of the system response for a given amount of the analyte under investigation. Different methodologies are proposed and executed for the above mentioned purpose. In this work, we have demonstrated the performance of chemometric methods to study the atomic emissions from simulated nuclear waste glasses. Five samples of iron‐phosphate glasses were synthesized by doping Cr, Sr, and Ti at various concentrations. The spectra recorded using laser‐induced breakdown spectroscopy (LIBS) system were analyzed using principal component analysis (PCA), partial least square‐discriminant analysis (PLS‐DA), and support vector machines (SVM) for the classification. As compared with the PLS‐DA, SVM provided better results for classification with accuracy of 100% on both calibration and validation sets, respectively. The quantitative analysis of glass samples is carried out using partial least square regression (PLSR) and support vector regression (SVR). The root mean squared error of prediction (RMSEP) is found to be 0.16, 0.20, and 0.08 (wt%) for Cr, Sr, and Ti using PLSR. The detailed investigation elucidates the advantages of chemometrics in handling the complex LIBS spectrum of glass samples and their significance in process control of nuclear waste, nuclear forensics, and so on. The performance evaluation of chemometric methods to study the atomic emissions from simulated nuclear waste glasses. [ABSTRACT FROM AUTHOR]

Large amounts of perfect crystals were excavated from ancient coffins dating 2510 (±50) bp, in Jing'an County, Jiangxi Province, China. The coffins were wrapped by multiple bamboo mats and sealed highly by waterproof soil layers. In this study, crystals, wooden coffins, surrounding water and clay materials of several buried wooden coffins were subject to various analyses, and the crystals were identified to be vivianite by single crystal X‐ray diffraction, X‐ray fluorescence (XRF) and infrared (IR) spectroscopy. Spatial distribution of the vivianite crystals, which was consistent with first Fick's diffusion principle, indicated that the phosphate (PO43−) of the vivianite was originated from human bone that was demineralized under an acidic clay condition. Spatial distributions of iron(III) oxide (Fe2O3) and iron(II) oxide (FeO) indicated that iron(II) cations (Fe2+) of the vivianite originated from clay outside the coffins. Perfect vivianite crystals were formed at an extremely slow rate within the highly sealed coffins, in which Fe2+ and PO43− concentrations were of such a low level that the rapid precipitation of imperfect vivianite crystals was prevented, as the clay colloid could infiltrate only along the limited passageways of jointed seams between two halved timbers of the coffins. [ABSTRACT FROM AUTHOR]

Abstract: High‐performance electric energy storage material has recently developed due to the attention for sustainable development. As ecofriendly energy storage device, lithium ion batteries and sodium ion batteries deserve more concern today. FePO4 and NaFePO4 share similar advantages such as easy preparation, abundant, and inexpensive, so they can be ideal materials for lithium/sodium ion batteries. This review is focused on recent progresses in nanostructured FePO4/NaFePO4‐based nanomaterial as cathode materials for lithium/sodium ion batteries. FePO4‐based materials contain crystalline and amorphous pure FePO4 nanomaterial, FePO4/C compounds, and other novel materials with unique morphologies. NaFePO4‐based materials contain olivine NaFePO4, Na4FeP2O7, and so on. They own unique properties, including preferable energy density, cycling performance, electrical conductivity, and charge/discharge stability. This review is designed to summarize the synthesis, morphology, and electrochemical property and application of FePO4‐based and NaFePO4‐based nanomaterials. There exist relations among the structure, property, and storage, which is also introduced. Furthermore, this review assesses the challenges and outlooks of FePO4/NaFePO4‐based nanomaterial for future development; it also sheds light on appropriate development direction of advanced rechargeable batteries with a focus on FePO4/NaFePO4‐based nanomaterial. [ABSTRACT FROM AUTHOR]

Abstract: LiFePO4@C/reduced graphene oxide (rGO) hierarchical microspheres with superior electrochemical activity and a high tap density were first synthesized by using a Fe3+‐based single inorganic precursor (LiFePO4OH@RF/GO; RF=resorcinol–formaldehyde, GO=graphene oxide) obtained from a template‐free self‐assembly synthesis followed by direct calcination. The synthetic process requires no physical mixing step. The phase transformation pathway from tavorite LiFePO4OH to olivine LiFePO4 upon calcination was determined by means of the in situ high‐temperature XRD technique. Benefitting from the unique structure of the material, these microspheres can be densely packed together, giving a high tap density of 1.3 g cm−3, and simultaneously, defectless LiFePO4 primary nanocrystals modified with a highly conductive surface carbon layer and ultrathin rGO provide good electronic and ionic kinetics for fast electron/Li+ ion transport. [ABSTRACT FROM AUTHOR]

3D microbatteries hold great promise as on-board energy supply systems for microelectronic devices. The construction of 3D microbatteries relies on the development of film deposition techniques that can enable coatings of uniform electrode and electrolyte materials in high-aspect-ratio substrates. Here, a 3D FePO4 on carbon nanotubes (CNTs@FePO4) structure is fabricated by coating FePO4 on CNTs/carbon paper substrate using atomic layer deposition. Compared to FePO4 on a planar substrate, the 3D CNTs@FePO4 electrode exhibits significantly increased areal capacity and excellent rate capability for lithium-ion and sodium-ion storage. The 3D CNTs@FePO4 maintains areal capacities of 64 and 33 μAh cm−2 after 180 cycles for lithium-ion batteries (LIBs) and sodium-ion batteries, which are 16 and 33 times higher than those of planar FePO4 electrode, respectively. Moreover, hybrid 3D CNTs@FePO4@Li3PO4 structure is fabricated by coating Li3PO4 solid-state electrolyte on 3D CNTs@FePO4. The CNTs@FePO4@Li3PO4 electrode shows stable cycling performance in LIBs. Hard X-ray photoemission spectroscopy analysis demonstrates that the Li3PO4 coating prevents the formation of undesirable LiF in the solid-electrolyte interphase layer, which is believed to be responsible for the performance degradation in CNTs@FePO4. This work paves the way to building reliable 3D nanostructured electrode and electrolyte architectures for high areal capacity microbatteries. [ABSTRACT FROM AUTHOR]