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Doping heterogeneous atoms can modulate electronic structure, which matters for creating efficient bifunctional electrocatalysts in realizing conversion of hydrogen and electricity. This study demonstrates that Fe-doped Ni 5 P 4 nanosheet arrays on nickel foam (Fe–Ni 5 P 4 /NF) using Prussian blue analogues as precursors are successfully synthesized by straightforward hydrothermal reactions and phosphating. Fe–Ni 5 P 4 /NF exhibits great efficiency in creating hydrogen from water under alkaline conditions. The Fe–Ni 5 P 4 /NF dual electrode just need a minimal cell voltage of 1.54 V at 10 mA cm−2 and maintain operational stability for a minimum of 50 h, demonstrating outstanding bifunctional properties. The introduction of Fe modifies the electronic configuration for Ni 5 P 4 , substantially boosting the activity of the electrocatalyst. This study offers a framework for designing splendid bifunctional electrocatalysts through synergistic doping strategies in electrochemical applications. Fe-doped Ni 5 P 4 nanosheet arrays on NF (Fe–Ni 5 P 4 /NF) were prepared using NiFe PBA/Ni(OH) 2 /NF as the precursor, demonstrating remarkable efficiency in both OER and HER. Unexpectedly, the Fe–Ni 5 P 4 /NF || Fe–Ni 5 P 4 /NF couple simply requires 1.54 V to reach 10 mA cm−2 in an alkaline environment. [Display omitted] • Fe-doped Ni 5 P 4 nanosheet arrays using Prussian blue analogues as precursors are successfully synthesized. • Fe–Ni 5 P 4 /NF dual electrode demonstrates outstanding bifunctional electrochemical properties. • Fe-doping modulates the electronic structure of Ni 5 P 4 and enhances the intrinsic activity of the material. • Phosphating enhances the accessibility of catalytic sites and preserves the morphology. [ABSTRACT FROM AUTHOR]

Highly efficient novel electrocatalysts for hydrogen/oxygen production are urgently required, for noble metal‐based catalysts substitution. Cobalt phosphides have shown great potential for serving as bifunctional catalysts, owing to the cost effectiveness and high conductivity. However, the water splitting ability of them is still not comparative with commercial noble counterparts. In this work, we reported a Br‐induced strategy, to obtain an ultra‐hydrophilic isostructural Br0.036─Co1.085P@NF catalyst by a gas‐solid reaction method. As a typical halogen element, the introduction of Br can greatly enhance the surficial hydrophilicity and thus further impart ideal adsorption ability for water molecules. Meanwhile, the electronic structure could be regulated to further induce the generation of isostructural cobalt phosphides (CoP/Co2P). As a result, the contact angle of Br0.036─Co1.085P@NF catalysts nearly cannot be caught owing to the ultra‐hydrophilicity. It is also confirmed that, the d‐band center of Co shows apparent negative shift after Br introduction, which reduces the adsorption energy of oxygen‐containing intermediates thereby facilitating the desorption process. Besides, the introduction of Br can also reduce the barrier of O2 formation, show more favorable dynamic behaviors. This work proved the accessibility for an effective design strategy on halogen‐induced isostructural transition metal phosphides catalysts for high‐performance overall water splitting. [ABSTRACT FROM AUTHOR]

Designing integrated overall water‐splitting catalysts that maintain high efficiency and stability under various conditions is an important trend for future development, yet it remains a significant challenge. Herein, novel nanoflower‐like tri‐metallic Ni–Ru–Mo phosphide catalyst ((Ni–Ru–Mo)P@F‐CDs), integrated with F‐doped carbon dots (F‐CDs), were synthesized via a straightforward hydrothermal process and subsequent phosphatization. Attributable to precise interface engineering and electronic structure optimization, (Ni–Ru–Mo)P@F‐CDs exhibit exceptional bi‐functional catalytic activity in alkaline conditions, achieving remarkably low overpotentials of 231 and 123 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, at a current density of 100 mA cm−2. Industrially, only 1.426 V is needed for the same efficacy. Additionally, the catalyst requires merely 1.508 and 1.564 V for overall water splitting in 1 M KOH and simulated seawater, respectively, at 100 mA cm−2. The catalyst also shows excellent stability, with minimal performance decline over 100 h within 100–200 mA cm−2. Density functional theory calculations indicate that the interface structure synergistically optimizes Gibbs free energy for H* and O* intermediates during HER and OER, respectively, accelerating electrochemical water‐splitting kinetics. [ABSTRACT FROM AUTHOR]

The first widespread occurrence of rare Na-, Ca-, and Mg,Mn,Fe-bearing phosphate chladniite was observed in meteorite Graves Nunataks (GRA) 12510, which is a primitive achondrite that sits within the winonaite class. Numerous 1–500 μm chladniite grains were found, often on the margins between silicate clasts and the kamacite portions of the large metal veins that permeated through the sample. The largest chladniite grains are associated with merrillite, kamacite, taenite, troilite, albite, forsterite, diopside, and enstatite, with a few tiny chladniite grains and an apatite grain enclosed within merrillite. GRA 12510s average chladniite composition is Na2.7Ca1.25(Mg10.02Mn0.69Fe0.20)Σ10.91(PO4)9. Electron backscattered diffraction (EBSD) patterns indicate varying degrees of nucleation and growth of chladniite grains. Additionally, the first pure Raman spectrum of chladniite is described here, revealing primary ν1 bands at 954, 974, and especially 984 cm–1. The co-occurrence and close association of merrillite, apatite, chladniite, and P-bearing metallic phases within GRA 12510 suggests that the fO2 of IW-2 to IW-4 is an intrinsic property of the precursor chondritic material, and the phosphatephosphide reaction may have buffered the final winonaite and IAB iron meteorite phase assemblages. Altogether, chladniite appears to form alongside other phosphates, with their chemistries reflecting the diverse environment of their formation. Meteoritic chladniite likely formed through subsolidus oxidation of schreibersite, scavenging Na from albite, Ca from diopside, Mg from enstatite/forsterite, Fe from kamacite/taenite, and Mn from alabandite/chromite when available. A P0-P5+ redox-buffered environment also has implications for thermometry and fast cooling rates, although more experiments are needed to extrapolate powder reaction rates to those of larger crystals. Furthermore, phosphidephosphate buffered experiments may aid in investigating equilibrium chemistry at fO2 values between IW-2 and IW-4, which have been challenging to explore experimentally due to the limited availability of solid metal-metal oxide buffers between IW (Fe-FeO) and IW-5 (Cr-Cr2O3) at temperatures and pressures relevant to planetary interiors. Future investigations of phosphide-phosphate redox-buffered genesis at fO2 values between IW-2 and IW-4 have important implications for primitive meteorite constituents (e.g., CAI values), partially differentiated planetesimals and planets, including Mercury and core formation on Earth. [ABSTRACT FROM AUTHOR]

Metal phosphide， as an emerging material for supercapacitors， has attracted more and more attention. In this paper， nickel-cobalt sulfide was obtained by hydrothermal method with carbon cloth （CC） as the substrate and nickel chloride and cobalt nitrate as the raw materials. Then nickel-cobalt phosphide （Ni1/2Co1/2P/CC） was finally obtained by low-temperature phosphating method with sodium hypophosphate as raw materials. Electrochemical tests were performed， and the results show that the specific capacitance of Ni1/2Co1/2P/CC is up to 0.87 F/cm2 at the current density of 2 mA/cm2. After 2000 cycles of charge and discharge at 30 A/cm2， the capacitance retention is 80.22%. In addition， with the Ni1/2Co1/2P/CC as positive electrode and the activated carbon （AC） as negative electrode，the asymmetric supercapacitor （Ni1/2Co1/2P/CC∥AC/NF） exhibits a high energy density of 0.25 mWh/cm3 at the power density of 104.99 mW/cm3.

Efficient and durable electrocatalysts toward alkaline hydrogen evolution reaction (HER) are of great significance for the widespread application of anion‐exchange membrane water electrolyzer (AEMWE). Numerous single‐phase catalysts, such as Ru2P, have been explored as efficient HER catalysts; however, many have failed to overcome the inherent sluggish kinetics of the two separate steps involved in the alkaline HER: water dissociation and hydrogen production. In this study, density functional theory calculations are conducted to identify promising combinations of Ir2P and Ru2P materials that promote fast cascade water dissociation and H2 production via kinetically favorable hydrogen spillover from the Ru2P surface to the adjacent Ir2P. An unprecedented construction of Ir2P cluster‐decorated Ru2P hollow nanotubes (c‐RP/IP HNTs), which feature a cooperative heterostructural synergy are developed. This configuration shows greater performance than commercial Pt/C, achieving an overpotential of 23.2 mV at 10 mA cm−2 and maintaining long‐term stability for 55 h in half‐cell tests. Furthermore, the practical AEMWE test, incorporating c‐RP/IP HNTs, demonstrated a remarkable single‐cell performance of 12.23 A cm−2 at 2.0 V and operated stably under 1.0 A cm−2 for over 250 h. This surpasses that of the state‐of‐the‐art proton‐exchange membrane WE. [ABSTRACT FROM AUTHOR]

[Display omitted] Transition metal phosphides have been demonstrated to be promising non-noble catalysts for water splitting, yet their electrocatalytic performance is impeded by unfavorable free energies of adsorbed intermediates. The achievement of nanoscale modulation in morphology and electronic states is imperative for enhancing their intrinsic electrocatalytic activity. Herein, we propose a strategy to expedite the water splitting process over NiCoP/FeNiCoP hollow ellipsoids by modulating the electronic structure and d-band center. These unique phosphorus (P) vacancies-rich ellipsoids are synthesized through an ion-exchange reaction between uniform NiCo-nanoprisms and K 3 [Fe(CN) 6 ], followed by NaH 2 PO 2 -assisted phosphorization under N 2 atmosphere. Various characterizations reveals that the titled catalyst possesses high specific surface area, abundant porosity, and accessible inner surfaces, all of which are beneficial for efficient mass transfer and gas diffusion. Moreover, density functional theory (DFT) calculations further confirms that the NiCoP/FeNiCoP heterojunction associated with P vacancies regulate the electronic structures of d-electrons and p-electrons of Co and P atoms, respectively, resulting in a higher desorption efficiency of adsorbed H* intermediates with a lower energy barrier for water splitting. Due to the aforementioned advantages, the resultant NiCoP/FeNiCoP hollow ellipsoids exhibit remarkably low overpotentials of 45 and 266 mV for hydrogen and oxygen evolution reaction to achieve the current densities of 10 and 50 mA cm−2, respectively. This work not only reports the synthesis of a hollow double-shell structure of NiCoP/FeNiCoP but also introduces a novel strategy for constructing a multifunctional electrocatalyst for water splitting. [ABSTRACT FROM AUTHOR]

Background: Phosphide metal poisoning results in tens of thousands of fatalities per year worldwide. The mortality in critically ill patients often exceeds 50%. The available treatment is supportive and there is no antidote. Dialysis is recommended to treat advanced complications but has not been prescribed early in the process. In this study we report our experience in using dialysis in the early hours of presentation of the patients and suggest it can favorably improve the prognosis. We also draw attention to the risk of suicide under conditions of chronic conflict such as those in northwestern Syria, and to the lack of necessary mental health support for patients after suicide attempts. Methods: Retrospective review of records of patients poisoned with aluminum phosphide and admitted to critical care facilities in northwestern Syria between July 2022 and June 2023. Results: During the observation period 16 cases were encountered. Suicide was the reason of the poisoning in 15 patients, the median patient age was 18 years and over two thirds of the patients were female. Early dialysis was used in 11 patients who were critically ill and their mortality rate was 18%. Conclusions: Phosphide metal poisoning is common in the disasters stricken area of northwestern Syria. Most cases are suicidal and impact young females. Early dialytic interventions may favorably impact the outcomes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phosphorus, a group V non-metallic element, exhibits a unique electronic structure along with excellent optical, electrical and mechanical properties, and has a wide range of application prospects. Recent studies have demonstrated that phosphorus and phosphides are easily affected and regulated by external fields and have rich physical and chemical properties under high pressure. In addition, the unique structure and electronic properties of phosphorus and phosphides give them many physical properties that differ from those of traditional materials. Therefore, the use of high pressure to induce structural transformation and superconducting transformation in phosphorus and phosphides has become the focus of high-pressure research. In this paper, the structural, electrical, and optical responses of black phosphorus, germanium phosphide, and arsenic phosphide under high-pressure conditions are reviewed and discussed. Furthermore, we also explore the structure-activity relationships between the structures and physical properties and forecast the future research directions of phosphides under high pressure. [ABSTRACT FROM AUTHOR]

Mineral assemblages formed at low oxygen fugacity are commonly confined to the lithologies of extraterrestrial or deep Earth origin. The occurrences of reduced mineral phases in upper crustal rocks [formed under oxygen fugacity conditions below the iron-wüstite (IW) buffer] are rare. However, they are important for understanding the chemical drivers of natural redox processes. Here, we present detailed studies of reduced mineral assemblages, which were found in situ in superficial combustion metamorphic (CM) rocks of west-central Jordan and compare them to reduced mineral assemblages found in situ in the CM rocks of south-central Israel. The studied assemblages contain a suite of exotic phases more typical of meteorites: native iron, phosphides (schreibersite, Fe3P; allabogdanite, Fe2P; transjordanite, Ni2P; murashkoite, FeP; halamishite, Ni5P4; zuktamrurite, FeP2; polekhovskyite, MoNiP2), and sulphides (daubréelite, FeCr2S4; oldhamite, CaS; troilite, FeS), part of which (native iron, allabogdanite, halamishite, polekhovskyite, daubréelite) have not previously been discovered in the CM rocks of west-central Jordan. The mineralogical diversity of terrestrial phosphides and the occurrence of Ni- / Mo-rich phases can be explained by (1) high P, Ni, and Mo content in the sedimentary protolith, (2) transformations of primary Fe3P / Fe2P, (3) extreme disequilibrium of the processes, and (4) crystal-chemical control of Ni- / Mo- speciation. [ABSTRACT FROM AUTHOR]

Abstract Designing integrated overall water‐splitting catalysts that maintain high efficiency and stability under various conditions is an important trend for future development, yet it remains a significant challenge. Herein, novel nanoflower‐like tri‐metallic Ni–Ru–Mo phosphide catalyst ((Ni–Ru–Mo)P@F‐CDs), integrated with F‐doped carbon dots (F‐CDs), were synthesized via a straightforward hydrothermal process and subsequent phosphatization. Attributable to precise interface engineering and electronic structure optimization, (Ni–Ru–Mo)P@F‐CDs exhibit exceptional bi‐functional catalytic activity in alkaline conditions, achieving remarkably low overpotentials of 231 and 123 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively, at a current density of 100 mA cm−2. Industrially, only 1.426 V is needed for the same efficacy. Additionally, the catalyst requires merely 1.508 and 1.564 V for overall water splitting in 1 M KOH and simulated seawater, respectively, at 100 mA cm−2. The catalyst also shows excellent stability, with minimal performance decline over 100 h within 100–200 mA cm−2. Density functional theory calculations indicate that the interface structure synergistically optimizes Gibbs free energy for H* and O* intermediates during HER and OER, respectively, accelerating electrochemical water‐splitting kinetics.

Copyright of Journal of Petrochemical Universities / Shiyou Huagong Gaodeng Xuexiao Xuebao is the property of Journal Editorial Department Of Liaoning Shihua University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recently, several ternary phosphidotrielates and ‐tetrelates have been investigated with respect to their very good ionic conductivity, while less focus was pointed towards their electronic structures. Here, we report on a novel series of compounds, in which several members possess direct band gaps. We investigated the known compounds Li3AlP2, Li3GaP2, Li3InP2, and Na3InP2 and describe the synthesis and the crystal structure of novel Na3In2P3. For all mentioned phosphidotrielates reflectance UV‐Vis measurements reveal direct band gaps in the visible light region with decreasing band gaps in the series: Li3AlP2 (2.45 eV), Li3GaP2 (2.18 eV), Li3InP2 (1.99 eV), Na3InP2 (1.37 eV), and Na3In2P3 (1.27 eV). All direct band gaps are confirmed by quantum chemical calculations. The unexpected property occurs despite different structure types. As a common feature all compounds contain EP4 tetrahedra, which share exclusively vertices for E=In and vertices as well as edges for E=Al and Ga. The structure of the novel Na3In2P3 is built up by a polyanionic framework of six‐membered rings of corner‐sharing InP4 tetrahedra. As a result, the newly designed semiconductors with direct band gaps are suitable for optoelectronic applications, and they can provide significant guidance for the design of new functional semiconductors. [ABSTRACT FROM AUTHOR]

Nanostructured ionic compounds have driven major technological advancements in displays, photovoltaics, and catalysis. Current research focuses on refining the chemical composition of such compounds. In this study, a strategy for creating stoichiometrically well‐defined nanoscale multiple‐cation systems, where the atomically precise structure maximizes the synergistic cooperation between cations at the atomic scale is reported. The unprecedented construction of Heusler‐type PtRuP2 double‐walled nanotubes through sequential anion/cation exchange reactions is demonstrated. The PtRuP2 catalyst exhibits record‐high catalytic performance and durability for the hydrogen evolution reaction (HER) in alkaline electrolytes and anion‐exchange membrane water electrolyzers. The investigations highlight the crucial role of Pt/Ru dual centers, providing multiple active sites that accelerate the HER kinetics within a single phosphide material, in the sequential operation of H2O activation/dissociation at Ru and H2 production at adjacent Pt sites. These findings open new avenues for optimizing ionic compound‐based HER electrocatalysts, offering platinum‐metal alternatives in acidic and alkaline media. [ABSTRACT FROM AUTHOR]

Effort to find efficient catalysts for the hydrogen evolution reaction (HER) continue due to the high cost and scarcity of Pt catalyst. This study centers on electrodeposited CoMoP, a transition metal-based catalyst, with a focus on augmenting its active sites. The Cu nanowires serve as a template, not only expanding the surface area of CoMoP but also aiding in electron acceptance due to their excellent electrical conductivity. Consequently, the surface area experiences an approximate 2.1-fold increase compared to the case without nanowires. Furthermore, the CoMoP on Cu nanowires exhibits a heterostructure with crystalline and amorphous phases, enhancing electrical conductivity and exposing active sites. This distinctive configuration facilitates the transfer of protons and electrons, thereby improving the electrocatalytic activity. As a result of this enhanced activity, the catalyst demonstrates fairly low overpotentials for HER in both alkaline and acidic conditions. At current densities of 10 and 100 mA cm−2 in alkaline environment, it only needs 32 and 117 mV, respectively. Similarly, in acidic environment, the overpotentials are 55 and 112 mV at 10 and 100 mA cm−2, respectively. The catalyst also shows good stability under both conditions. [Display omitted] • To increase surface area, Cu foam with Cu nanowires served as the substrate. • Heterostructure CoMoP catalyst was electrodeposited on the substrate. • The CoMoP catalyst underwent HER testing in acidic and alkaline conditions. • The CoMoP catalyst showed high HER activity and stability in both conditions. [ABSTRACT FROM AUTHOR]

Two novel cyclic Al3 clusters, Li2[Al3(PR2)6] ⋅ 2(Et2O) [R=Ph (1), Cy (2)] were synthesized through salt metathesis of metastable AlCl ⋅ (Et2O)n solutions with LiPR2. Both complexes were characterized by single crystal X‐Ray diffraction and their solid state and electronic structures are compared to previously reported cyclic Al3 clusters. Compounds 1 and 2 were further characterized using density functional theory (DFT) methods to understand the nature of the free electron and the three‐center two‐electron Al−Al bonds. Calculations revealed that both clusters are influenced by pseudo Jahn‐Teller distortion and are likely in equilibrium between two low energy bonding states. The solid‐state structures of 1 and 2 are unique among Al3 clusters, while the electronic structure is similar to the previously reported [Sit4Al3]. In aluminum chemistry, 1 and 2 are rare examples of clusters containing isoelectronic cores in different ligand environments. The effects of the phosphide ligand sphere and strongly coordinated lithium atoms are discussed in detail. [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-supported amorphous CoFe-P/NF electrode was fabricated by electrodeposition. • HER and PET plastic oxidation properties were promoted by CoFe-P/NF. • H 2 and formate were coproduced by energy saving electrolysis of PET hydrolyte. • The amorphous CoFe-P and surface oxide layer lead to bifunctional catalytic features. The electrocatalytic hydrogen evolution reaction (HER) coupled with oxidative transformation of plastics into commodity chemical is a promising tactic to relieve the energy shortage and white pollution problems via sustainable and profitable manner, which necessitates highly active bifunctional catalytic electrode and meticulous construction of electrolysis system. Herein, a self-supported amorphous cobalt iron phosphide onto nickel foam (NF) substrate, labeled as CoFe-P/NF, was prepared by electrodeposition, which served as bifunctional catalytic electrode for alkali hydrogen evolution reaction (HER) and selective electrooxidation of polyethylene terephthalate (PET) plastic hydrolysate toward formate. Benefiting from the abundant catalytic sites within amorphous structure, the interelement synergy and sufficient exposure of catalyst to electrolyte, the self-supported CoFe-P/NF electrode displayed low overpotential (η 100 of 168 mV at current density of J = 100 mA cm−2), decent stability for HER and fine tolerance to PET monomers. The CoFe-P/NF electrode could also catalyze selective electrooxidation of ethylene glycol (EG) component in PET hydrolysate to formate with high productivity (0.1 mmol cm-2h−1) and faradaic efficiency (FE, 90 %) at 1.5 V. The PET hydrolysate electrolysis system based on CoFe-P/NF enabled coproduction of H 2 and value added formate at lower voltage (1.52 V at J = 20 mA cm−2) and energy consumption (84 % at J = 200 mA cm−2) relative to water electrolysis. This work showcases the coproduction of H 2 fuel and formate by electrolysis of PET hydrolysate via rational design of bifunctional catalytic electrode. We believe such type of versatile catalytic electrodes can find application scenarios in electrosynthesis of more commodity chemicals and energy devices beyond the case herein. [ABSTRACT FROM AUTHOR]

[Display omitted] Beyond round nanofibers, electrospinning method is able to fabricate thin fibers with various cross-sectional shapes. In this work, using phosphomolybdic acid to trigger the polymerization reaction of pyrrole with addition of tin salt for the filler of carbon fibers, we prepared quasi-two-dimensional thick belt-like fibers through single spinneret electrospinning. The side-by-side welding nanofiber bundles with dog-bone-shaped cross-section improved the connection between fibers, endowing the fiber films with some flexibility and enabling it to be used as freestanding electrode. Employed as anode for sodium/potassium ion storage, the carbon fiber encapsulated MoP/SnO 2 material exhibited promising electrochemical performance. Controlling the collection process of electrospinning, the electrode mass loading can be increased to 10 mg cm−2. Combined with surface selenizing modification, the performance of as-prepared MoP/SnO 2 /MoSe 2 was further improved, which exhibited areal capacity about 1.5 mAh cm−2 as anode for sodium/potassium ion storage with mass loading of 8–9 mg cm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-supported p-n junction catalytic electrode was prepared by electrodeposition. • Efficient charge redistribution occurred within the p-n junction. • Decent OER, HER and 4-NP hydrogenation performances were ensured. • H 2 production and hydrogenation valorization of 4-NP were fulfilled by catalysis. Charge redistribution across heterointerfaces is an important tactic to enhance the catalytic activities and bifunctionality of hybrid catalysts, especially for green hydrogen production from water electrolysis and harmless electrocatalytic valorization of organics. Herein, a self-supported p-n junction catalytic electrode was constructed by tandem electrodeposition of nickel cobalt phosphide (NiCoP) and nickel iron layered double hydroxide (NiFe LDH) onto Ni foam (NF) substrate, denoted as NiCoP@NiFe LDH/NF, to enhance the electrocatalytic capabilities for water electrolysis and hydrogenation of an organic, para -nitrophenol (4-NP). Benefitting from the charge redistribution across the p-n junction, high electrocatalytic efficiencies for oxygen evolution reaction (OER, overpotential of 388 mV at 100 mA cm−2) and hydrogen evolution reaction (HER, overpotential of 132 mV at 10 mA cm−2) could be achieved concurrently by the NiCoP@NiFe LDH/NF electrode, and both overpotentials were located within the mainstream levels in this domain. The bifunctional catalytic features enabled a full water electrolysis response of 10 mA cm−2 at 1.61 V. In addition, the p-n junction electrode catalyzed the hydrogenation of 4-NP at a conversion of 100%, para -aminophenol (4-AP) selectivity of 90% and faradaic efficiency (FE) of 88% at −0.18 V. The current work offers a feasible strategy for fulfilling electrochemical H 2 production and hydrogenation valorization of 4-NP pollutant by constructing a self-supported p-n junction catalytic electrode. [ABSTRACT FROM AUTHOR]

[Display omitted] • NiFeRu/C and Ru, Fe-Ni 5 P 4 /C nanofibers as complementary electrocatalyst toward water splitting were synthesized. • The electrolytic cell based NiFeRu/C||Ru, Fe-Ni 5 P 4 /C presents outstanding water splitting activity owing to their complementary activity. • NiFeRu/C||Ru, Fe-Ni 5 P 4 /C requires voltage of 1.569, 1.744 and 1.872 V to achieve 100, 500 and 1000 mA cm−2, respectively. • NiFeRu/C||Ru, Fe-Ni 5 P 4 /C can work stability at 500 mA cm−2 for 100 h. Designing and fabricating highly competent and inexpensive electrocatalysts are highly desirable for application in electrocatalytic water splitting. In this study, we synthesized NiFeRu/C nanofibers and Ru, Fe dual-doped Ni 5 P 4 (Ru, Fe-Ni 5 P 4)/C nanofibers as complementary electrocatalysts for overall water splitting through electrospinning, carbonization, and phosphorization treatment, respectively. The NiFeRu/C nanofibers and Ru, Fe-Ni 5 P 4 /C nanofibers showed high hydrogen evolution reaction and oxygen evolution reaction activity, respectively, due to the presence of numerous exposed active sites and optimized adsorption capacity for the reaction intermediates contributed by the synergistic interaction among different metal components in the electrocatalysts. Hence, the assembled asymmetrical electrolytic cell effectively promoted overall water splitting, requiring a voltage of 1.569, 1.744, and 1.872 V to achieve a current density of 100, 500, and 1,000 mA cm−2, respectively, and it was better than Pt/C||IrO 2. Additionally, the electrolytic cell could work at 500 mA cm−2 for 100 h without any noticeable deterioration in activity, which indicated that it was durable at high current density. In this study, we described a novel method for designing highly efficient electrocatalysts for overall water splitting. [ABSTRACT FROM AUTHOR]

This paper reports thermodynamic properties and phase equilibria in the iron-phosphoruscarbon system for developing a technology for smelting ferrophosphorus as well as for utilizing them in the processes of phosphorus-alloying of metals. According to the results of thermodynamic calculations, we plotted a ternary Fe--P--C phase equilibrium diagram (liquidus surface) in the form of graphical dependences, which indicate the concentration fields of phase coexistence. The results of simulation allowed finding out five nonvariant points, three of which are new: E1 eutectic (teutectic=1217°), U1 peritectic (tperitectic=1095°), and E3 eutectic (teutectic=338°). The experimental studies of the phase composition of ferrophosphorus showed that the phosphorus microstructure is represented by Fe3P phosphide, Fe3C carbide, and carbophosphide eutectic. We carried out the thermodynamic calculation of the temperature-concentration ranges of phase stability in the Fe--P--C system that are at equilibrium with the smelts of both the carbon solid solutions and phosphorus ones in α- and γ-iron, FeP, Fe2P, Fe3P phosphides, and graphite. In this study, three previously unknown nonvariant equilibria have been determined: a eutectic equilibrium at 1216.58°C; a peritectic one with a transformation point at 1095.19°C; and a eutectic one at a temperature of 337.51°C. In experiments, we obtained an equilibrium concentration of carbon which decreases in the Fe--P--C system when the content of phosphorus increases. The research findings largely reveal special features of preparation of ferrophosphorus by carbon reduction of phosphorites. [ABSTRACT FROM AUTHOR]

Yakubovichite, CaNi2Fe3+(PO4)3, a new mineral containing up to 20 wt% NiO, represents a novel type of terrestrial phosphate mineralization featuring an extreme enrichment in Ni. The mineral was discovered in the Hatrurim Formation (Mottled Zone)—pyrometamorphic complex whose outcrops are exposed in Israel and Jordan in the area coincident with the Dead Sea Transform fault system. Nickel-rich minerals in these assemblages also include Ni phosphides: halamishite Ni5P4, negevite NiP2, transjordanite and orishchinite—two polymorphs of Ni2P, nazarovite Ni12P5, polekhovskyite MoNiP2; Ni-spinel trevorite NiFe2O4, bunsenite NiO, and nickeliferous members of the hematite-eskolaite series, Fe2O3-Cr2O3 containing up to 2 wt% NiO. Yakubovichite forms polycrystalline segregations up to 0.2 mm in size composed of equant crystal grains, in association with crocobelonite, hematite, other phosphates, and phosphides. It has a deep yellow to lemon-yellow color, is transparent to translucent with vitreous luster, and has no cleavage. Mohs hardness = 4. Yakubovichite is orthorhombic, Imma, unit-cell parameters of the holotype material: a = 10.3878(10), b = 13.0884(10), c = 6.4794(6) Å, V = 880.94(2) Å3, Z = 4. Chemical composition of holotype material (electron microprobe, wt%): Na2O 1.82, K2O 1.76, CaO 6.37, SrO 0.49, BaO 1.37, MgO 2.13, NiO 21.39, CuO 0.16, Fe2O3 18.80, Al2O3 1.06, V2O3 0.44, Cr2O3 0.15, P2O5 44.15, total 100.09. The empirical formula calculated on the basis of 12 O atoms per formula unit is (Ca0.55Na0.29K0.18Ba0.04Sr0.02)1.08(Ni1.39Mg0.26Fe30.24+ V30.03+ Cu0.01Cr0.01)Σ1.94 (Fe30.90+ Al0.10)Σ1P3.02O12. Dcalc = 3.657 g cm–3. The strongest lines of powder XRD pattern [d(Å)(I)(hkl)]: 5.82(44)(011), 5.51(73)(101), 5.21(32)(200), 4.214(34)(121), 2.772(97)(240), 2.748(100)(202), 2.599(38)(400). Yakubovichite is the first mineral that crystallizes in the α-CrPO4 structure type. It has a direct synthetic analog, CaNi2Fe3+(PO4)3. Since yakubovichite is the first natural Ni-phosphate of non-meteoritic origin, the possible sources of Ni in the reported mineral assemblages are discussed. Pyrometamorphic rocks of the Hatrurim Formation were formed at the expense of the sediments belonging to a Cretaceous-Paleogene (Cretaceous-Tertiary) boundary (~66 Ma age). This geological frame marks the event of mass extinction of biological species on Earth that was likely caused by the Chicxulub impact event. The anomalous enrichment of pyrometamorphic assemblages in Ni may be related to metamorphic assimilation of Ni-rich minerals accumulated in the Cretaceous-Paleogene layer, which was formed due to a Chicxulub collision. [ABSTRACT FROM AUTHOR]

Crocobelonite, CaFe23+(PO4)2O, is a new natural oxyphosphate discovered in the pyrometamorphic complexes of the Hatrurim Formation in Israel and Jordan. Crocobelonite-bearing assemblages contain a series of anhydrous Fe-Ni phosphates, hematite, diopside, anorthite, and phosphides—barringerite Fe2P, transjordanite Ni2P, murashkoite FeP, halamishite Ni5P4, and negevite NiP2. Crocobelonite forms submillimeter-sized aggregates of prismatic to acicular crystals of saffron-red to pinkish-red color. There are two polymorphic modifications of the mineral whose structures are interrelated by the unit-cell twinning. Crocobelonite-2O is orthorhombic, Pnma, a = 14.2757(1), b = 6.3832(1), c = 7.3169(1) Å, V 666.76(1) Å3, Z = 4. This polymorphic modification is isotypic with synthetic oxy-phosphates A V 2 3 + P O 4 2 O where A = Ca, Sr, Cd. The crystal structure has been refined to RB = 0.71% based on powder XRD data, using the Rietveld method and the input structural model obtained from the single-crystal study. Chemical composition (electron microprobe, wt%) is: CaO 16.03, MgO 0.56, Fe2O3 43.37, Al2O3 0.33, SiO2 0.32, P2O5 39.45, Total 100.06. The empirical formula based on O = 9 apfu is C a 1.02 F e 1.94 3 + M g 0.05 A l 0.02 2.01 P 1.98 S i 0.02 2.00 O 9.00 The strongest lines of powder XRD pattern [d(Å)(I)(hkl)] are: 6.54(16)(200), 5.12(26)(201), 3.549(100)(102), 3.200(50) (401), 2.912(19)(220), 2.869(40)(411), 2.662(21)(501). Crocobelonite- 1M is monoclinic, P21/m, a = 7.2447(2), b = 6.3832(1), c = 7.3993(2) Å, β = 106.401(2)°, V = 328.252(14) Å3, Z = 2. This polymorphic modification does not have direct structural analogs. Its crystal structure has been solved and refined based on the single-crystal data to R1 = 1.81%. Chemical composition is: CaO 15.56, MgO 0.16, NiO 0.78, Fe2O3 41.28, Al2O3 0.45, V2O3 0.42, Cr2O3 0.23, TiO2 0.79, P2O5 39.94, Total 99.61, corresponding to the empirical formula (O = 9 a p f u) C a 0.99 F e 1.85 3 + N i 0.04 T i 0.04 A l 0.03 V 0.02 3 + C r 0.01 M g 0.01 2.00 P 2.01 O 9.00 with Dcalc = 3.604 g/cm3. The strongest lines of powder XRD pattern [d(Å)(I)(hkl)] are 6.98(17)(100), 4.40(22)(101), 3.547(100)(201), 3.485(21)(200), 3.195(50)(020), 2.855(38)(102), 2.389(33)(122). Crocobelonite represents a novel type of phosphate mineral formed by oxidation of phosphide minerals at temperatures higher than 1000 °C and near-atmospheric pressure (pyrolytic oxidation). [ABSTRACT FROM AUTHOR]

Materials with cobalt and nickel phosphides of the general formula Me2P and iron phosphide deposited on highly porous silica (Ssp 811 m2/g) were obtained by the sol-gel method. The advantage of these methods for obtaining materials considered in the work is the absence of the need to use structure-forming substances, such as surfactants. The properties of materials obtained by different methods were compared. The fraction of deposited metals is 4.5–4.7 wt % for all the materials. [ABSTRACT FROM AUTHOR]

At present, Ru dopants mainly enhance electrocatalytic performance by inducing strain, vacancy, local electron difference, and synergy. Surprisingly, this work innovatively proposes that trace Ru atoms induce dual-reconstruction of phosphide by regulating the electronic configuration and proportion of Co-P/Co-O species, and ultimately activate superb electrocatalytic performance. Specifically, Ru-CoFeP@C/nickel foam (NF) is reconstructed to generate hydrophilic Co(OH)2 nanosheets during the hydrogen evolution reaction (HER) process, further accelerating the alkaline HER kinetics of phosphide. And the as-formed CoOOH during the oxygen evolution reaction (OER) process directly accelerates the oxygen overflow efficiency. As expected, the overpotential at 100 mA·cm−2 (η100) values of the reconstructed Ru-CoFeP@C/NF are 0.104 and 0.257 V for HER and OER, which are greatly lower than that of Pt/C-NF and RuO2-NF benchmarks, respectively. This work provides guidance for the construction of high-performance catalysts for HER and OER dual reconstruction. This work provides a new idea for the optimization of catalyst structure and electrocatalytic performance. [ABSTRACT FROM AUTHOR]

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[Display omitted] • NiFeP-rGO hybrid was prepared by phosphorization of NiFe PBA-GO precursor. • High activity, rapid kinetics and low activation energy for OER were demonstrated. • Efficient water electrolysis with high FEs for H 2 and O 2 were achieved. Efficient and bifunctional nonprecious catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are essential for the production of green hydrogen via water electrolysis. Transition metal (Ni, Co, Fe, etc.) phosphides are frequently documented HER catalysts, whereas their bimetallic oxides are efficient OER catalysts, thus enabling bifunctional catalysis for water electrolysis via proper operation. Herein, phosphide-reduced graphene oxide (rGO) hybrids were prepared from graphene oxide (GO)-incorporated bimetal Prussian blue analog (PBA) precursors. The hybrids could experience partial surface oxidation to create oxide layers with OER activities, and the hybrids also possessed considerable HER properties, therefore enabling bifunctional catalytic features for water electrolysis. The typical NiFeP-rGO hybrid demonstrated an overpotential of 250 mV at 10 mA cm−2 and good durability for OER, as well as moderate HER catalytic features (overpotential of 165 mV at −10 mA cm−2 and acceptable catalytic stability). Due to the bifunctional catalytic features, the NiFeP-rGO-based symmetric water electrolyzer demonstrated a moderate input voltage and high faradaic efficiency (FE) for O 2 and H 2 production. The current work provides a feasible way to prepare OER and HER bifunctional catalysts by facile phosphorization of PBA-associated precursors and spontaneous surface oxidation. Given the oxidation/reduction bifunctional catalytic behaviors, phosphide-rGO hybrid catalysts have great potential for widespread application in fields beyond water electrolysis, such as electrochemical pollution abatement, sensors, energy devices and organic syntheses. [ABSTRACT FROM AUTHOR]

[Display omitted] Designing two-dimensional (2D) heterostructures based on suitable energy materials is a promising strategy to achieve high-performance supercapacitors with hybridized transition metal and carbonaceous-based electrodes. The influence of each component and its content on the capacitor performance necessitates deeper insights. In this study, a 2D/2D heterostructure made of hierarchical pseudocapacitive cobalt phosphide/oxide and P-doped reduced graphene oxide (PrGO) nanosheets (CoP/CoO@PrGO) was fabricated using porous zeolitic-imidazolate framework precursor. The decoration of 2D leaf-like CoP/CoO hybrid onto PrGO could create a unique interface with a large number of active sites, CoO-driven creation of pseudocapacitive surface PO x species, and high P content (∼3 at.%) in PrGO, thus promoting the Faradaic reaction, electrical conductivity, and overall charge storage. This framework yields a high specific capacitance of 405 F g−1 at 5 A g−1 and excellent cycling stability (over 100 % after 10,000 cycles), superior to those of pristine CoP@PrGO (300 F g−1 at 5 A g−1). Furthermore, the fabricated asymmetric supercapacitor delivers reasonable energy density of 4.2 Wh kg−1 at a power density of 785 W kg−1 and cycling stability of ∼100 % after 10,000 cycles. Therefore, CoP/CoO@PrGO with its unique interfacial properties can promote the development of heterostructure electrode for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

The metal-rich phosphide TaCrP forms from the elements by step-wise solid state reaction in an alumina crucible (maximum annealing temperature 1180 K). TaCrP is trimorphic. The structural data of the hexagonal ZrNiAl high-temperature phase (space group P 6 ‾ 2 m ) was deduced from a Rietveld refinement. At room temperature TaCrP crystallizes with the TiNiSi type (Pnma, a = 623.86(5), b = 349.12(3), c = 736.78(6) pm, wR = 0.0419, 401 F2 values, 20 variables) and shows a Peierls type transition below ca. 280 K to the monoclinic low-temperature modification (P121/c1, a = 630.09(3), b = 740.3(4), c = 928.94(4) pm, β = 132.589(5)°, wR = 0.0580, 1378 F2 values, 57 variables). The latter phase transition is driven by pairwise Cr–Cr bond formation out of an equidistant chain in o-TaCrP. The phase transition was monitored via different analytical tools: differential scanning calorimetry, powder synchrotron X-ray diffraction, magnetic susceptibility measurements and 31P solid state NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Abstract Although transition metal phosphide electrocatalysts display unique electronic structure that serves as functional centers for hydrogen evolution reaction, the synthesis of this class of materials for oxygen evolution remains a challenge due to the complex multielectron transfer pathways and sluggish reaction kinetics. This study details an in‐situ modification and transformation of cyanide‐bridged nickel‐iron (CN‐NiFe) organometallic hybrid into the preferential Fe2P phase with prevailing exposed 12¯0 faceted active centers by leveraging on the facile coordinate cleavage dynamics and compound reactivity of labile metal organic coordination frameworks. The resultant transition metal phosphide attains high electrochemical surface area, low Tafel slope, and low overpotential for the oxygen evolution reaction, while also demonstrating bifunctional electrocatalytic performance for overall water splitting. Comprehensive experimental studies and density functional theory calculations reveal that the exceptional catalytic activity originates from the transformation of framework metallic sites into preferential active sites allows an optimal adsorption of oxygen evolution reaction intermediates.

In this work, mixed Ni/Co and Ni/Fe metal phosphides with different metal ratios were synthesized through the phosphidization of high-surface-area hydroxides grown hydrothermally on carbon cloth. The materials were characterized by means of X-ray photoemission spectroscopy, X-ray diffraction, energy dispersive X-ray analysis, and electron microscopies. The electrocatalytic performance in the electrochemical water splitting was tested in alkaline media. With the aim of determining the chemical stability of the mixed phosphides and the possible changes undergone under catalytic conditions, the materials were characterized before and after the electrochemical tests. The best performances in the hydrogen evolution reaction were achieved when synergic interactions are established among the metal centers, as suggested by the outstanding performances (50 mV to achieve 10 mA/cm2) of materials containing the highest amount of ternary compounds, i.e., NiCoP and NiFeP. The best performances in the oxygen evolution reaction were reached by the Ni-Fe materials. Under these conditions, it was demonstrated that a strong oxidation of the surface and the dissolution of the phosphide/phosphate component takes place, with the consequent formation of the corresponding metal oxides and hydroxides. [ABSTRACT FROM AUTHOR]

Light-matter interactions in low-dimensional quantum-confined structures can dominate the optical properties of the materials and lead to optoelectronic applications. In anisotropic layered silicon diphosphide (SiP2) crystal, the embedded quasi-one-dimensional (1D) phosphorus-phosphorus (P—P) chains directly result in an unconventional quasi-1D excitonic state, and a special phonon mode vibrating along the P—P chains, establishing a unique 1D quantum-confined system. Alloying SiP2 with the homologous element serves as an effective way to study the properties of these excitons and phonons associated with the quasi-1D P—P chains, as well as the strong interaction between these quasiparticles. However, the experimental observation and the related optical spectral understanding of SiP2 with isoelectronic dopants remain elusive. Herein, with the photoluminescence and Raman spectroscopy measurements, we demonstrate the redshift of the confined excitonic peak and the stiffening of the phonon vibration mode B1g3 of a series of Si(P1−xAsx)2 alloys with increasing arsenic (As) compositions. This anomalous stiffening of is attributed to the selective substitution of As atoms for P atoms within the P—P chains, which is confirmed via our scanning transmission electron microscopy investigation. Such optical spectra evolutions with selective substitution pave a new way to understand the 1D quantum confinement in semiconductors, offering opportunities to explore quasi-1D characteristics in SiP2 and the resulting photonic device application. [ABSTRACT FROM AUTHOR]

The preparation of inexpensive and efficient electrocatalysts for oxygen evolution reaction (OER) is crucial in the widespread application of water electrolyzers. A simple one-step aqueous electrodeposition method is utilized to prepare amorphous nickel-iron sulfide (Ni–Fe–S) and phosphide (Ni–Fe–P) films on Ni foam. The deposited films are highly porous, and can convert to active electrocatalysts for OER. In 1 M KOH, the Ni–Fe–S shows the highest OER activity, and requires only 230 mV overpotential to reach 0.05 A cm−2 OER current densities. The Fe–Ni–S also sustains the 30 h 0.05 A cm−2 galvanostatic OER test. Ex-situ characterizations show that sulfur in the Fe–Ni–S is oxidized and leached into the solution during OER, and that (oxy)hydroxide layer is formed at the surface. The adsorption energy of the hydroxyl group, an OER intermediate, is tuned by the electron interaction between the Ni and Fe, and the Ni–Fe–S exhibits the optimum hydroxyl group adsorption energy and the most facile OER kinetics. Also, higher intrinsic OER activity is observed for the electrodeposited amorphous nickel phosphide-derived film than the amorphous nickel sulfide-derived film. [Display omitted] • One-step electrodeposition of Ni–Fe sulfide and phosphide films on Ni foam. • The Ni–Fe–S shows the highest OER activity, with 0.23 V overpotential at 0.05 A cm−2. • The electron interaction tunes the hydroxyl adsorption energy and accelerates OER. • Nickel phosphide exhibits higher intrinsic OER activities than nickel sulfide. [ABSTRACT FROM AUTHOR]

Polekhovskyite, MoNiP2, is the first terrestrial Mo phosphide, a phosphorus-rich homolog of meteoritic monipite, MoNiP. The mineral represents a novel phosphide type of terrestrial Mo speciation. It was discovered among phosphide assemblages in pyrometamorphic rocks of the Hatrurim Formation (the Mottled Zone) in Israel, the area confined to the Dead Sea Transform fault system. Polekhovskyite occurs in the altered diopside microbreccia, as micrometer-sized euhedral crystals intimately intergrown with murashkoite, FeP and transjordanite, Ni2P, in association with Si-rich fluorapatite, hematite, and magnetite. In reflected light, the mineral has a bluish-gray color with no observable bireflectance and anisotropy. Chemical composition (electron microprobe, wt%): Mo 44.10, Ni 22.73, Fe 4.60, P 29.02, total 100.45, which corresponds to the empirical formula Mo0.99(Ni0.83Fe0.18)1.01P2.01 and leads to the calculated density of 6.626 g/cm. Polekhovskyite is hexagonal, space group P63/mmc, a = 3.330(1), c = 11.227(4) Å, V = 107.82(8) Å3, and Z = 2. The crystal structure has been solved and refined to R1 = 0.0431 based on 50 unique observed reflections. The occurrence of Mo-bearing phosphides at the Dead Sea Transform area is a regional-scale phenomenon, with the localities tracked across both Israel and Jordan sides of the Dead Sea. The possible sources of Mo required for the formation of Mo-bearing phosphides are herein reviewed; they are likely related to the processes of formation of the Dead Sea Transform fault system. The problem of anthropogenic contamination of geological samples with Mo and Ni is also discussed in the paper in the context of the general aspects of discrimination between natural and technogenic ultra-reduced phases. [ABSTRACT FROM AUTHOR]

Abstract Because of features, such as adjustable structures, high porosity, and high crystallinity, metal–organic frameworks (MOFs) deservedly have received considerable attention. Nevertheless, there is still room for improvements in the electrical conductivity and chemical stability of some MOFs, because of which they cannot be utilized as electrode materials. Fortunately, MOF derivatives have received widespread attention in recent years, especially phosphide materials, which are widely used in practical applications because of their outstanding conductivity, excellent specific surface area, and standout charge mobility. In this review, the latest developments of MOF‐derived phosphides in electrocatalysis related to energy, including the excellent performance in terms of electrochemical energy storage and ingenious strategies, and diversified synthetic approaches have been emphasized and summarized. Additionally, the arduous task and feasible proposals of MOF‐derived phosphides are also discussed.

Mid-infrared nonlinear optical (MIR-NLO) crystals are a key component in the field of high-precision measurements. Among these, phosphide (Pn; Pn = P, As) materials are renowned for their formidable polarization capabilities and hold substantial research potential. In this work, four non-cubic Pn materials (NaGe 3 P 3 , Cd 3 Cu 2 P 10 , Sr 14 Sn 3 As 12 , and Ba 13 Si 6 Sn 8 As 22) were systematically investigated using Density Functional Theory (DFT). Notably, the four materials are all composed of tri-coordinated groups and tetra-coordinated groups ("3 + 4"). The electronic and optical properties of these materials were systematically analyzed. The strong Second Harmonic Generation (SHG) properties of Cd 3 Cu 2 P 10 , Sr 14 Sn 3 As 12 , and Ba 13 Si 6 Sn 8 As 22 were predicted for the first time. Additionally, the contributions of different groups to polarizability and nonlinear polarizability were analyzed. In these "3 + 4" Pn materials, phase-matching was found to primarily arise from tri-coordinated groups, while the contributions to SHG predominantly stemmed from the groups with higher Pn content. The present study provides frontier theoretical guidance for high-performance MIR-NLO crystals in future research. [Display omitted] [ABSTRACT FROM AUTHOR]

Water electrolysis, a pivotal process for the production of green hydrogen, is a crucial step toward realizing the hydrogen economy. To advance its industrialization, it is essential to develop a highly efficient and economical catalyst along with a low-resistance electrolyzers. In pursuit of this goal, we synthesize a cost-effective iron-doped nickel phosphide electrocatalyst through a hydrothermal synthesis followed by post-phosphorization process. This catalyst exhibits exceptional performance, with an overpotential at 10 mA cm-2 (η 10) of 216 mV for oxygen evolution reaction, the rate-determining step for water electrolysis. It overperforms the that of pristine nickel phosphide (NiPx, η 10 = 284 mV). Operando X-ray absorption spectroscopy reveals the robust nature of the iron-doped nickel phosphide catalyst during water electrolysis, in stark contrast to the pristine nickel phosphide, which undergoes oxidation, thereby impacting overall catalytic activity. When integrated into a membrane-electrode assembly (MEA) system, our iron-doped nickel phosphide displays voltages of 1.51 V at 10 mA cm-2 (EE = 81.5%) and 1.66 V at 100 mA cm-2 (EE = 76.4%) without iR-correction. Moreover, it achieves a current density of 345 mA cm-2 at an applied voltage of 2 V without iR-correction, meeting industrial criteria. These findings underscore the superior catalytic activity of the robust phosphide phase for water electrolysis. [ABSTRACT FROM AUTHOR]

• The one-step phosphide synthesis method simplifies the preparation process, helps maintain high purity and consistency of the material, and reduces impurities and defects. • CoFeP heterogeneous metal phosphide electrocatalyst, formed from CoFe alloy via a one-step phosphide reaction converting Fe 2 P, CoP 2 and Co 2 P. • At 10 mA cm−2, Co-0.0032-FeP showed lower overpotentials of 127 and 266 mV for HER and OER, respectively. Many researchers have made efforts on designing and synthesizing catalytic active site as well as deciphering how exactly they catalyze the reaction to obtain electrocatalysts with superior water splitting activity. However, the development of high-performance dual-functional non-precious metal electrocatalysts for Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) remains challenging. In this study, CoFe undergoes in a one-step phosphorylation reaction converted to Fe 2 P, CoP 2 and Co 2 P, abbreviated as heterojunction metal phosphide (CoFeP). The Co/Fe ratio can be flexibly adjusted by controlling the content of Co in the synthesis process, which results in CoFeP with different morphologies. Benefiting from the porous structure and higher catalytic active sites, the Co-0.0032-FeP presents a lower overpotential of 127 mV and 266 mV for HER and OER of 10 mA cm−2 in a KOH solution, respectively. In addition, the low Tafel Slope and stable current density of Co-0.0032-FeP indicate fast kinetics and high stability in the HER. [ABSTRACT FROM AUTHOR]

The crystal structure of the ternary phosphide Ce 2 Ni 12 P 5 (La 2 Ni 12 P 5 -type structure) has been determined from X-ray powder diffraction data: full profile refinement, monoclinic symmetry, space group P 2 1 / m , a = 10.7809(2) Å, b = 3.6869(1) Å, c = 13.1490(3) Å, β = 107.776(4)º, R I = 0.068, R P = 0.044, R wP = 0.060. Ce 2 Ni 12 P 5 is a ferromagnet with a Curie temperature of 5.8(5) K. A significant deviation from the linearity of the temperature dependence of the electrical resistance for Ce 2 Ni 12 P 5 has been found. The low-temperature part of the electrical resistance indicates the presence of magnetic interactions in Ce 2 Ni 12 P 5. The influence of a magnetic field on the electrical resistance of Ce 2 Ni 12 P 5 has been studied. The X-ray absorption spectrum at the Ce L III edge and X-ray emission spectra of Ni and P at the K and L III edges have been studied experimentally and theoretically using DFT+ U calculations. The calculations show good agreement with the experimental measurements. The effective valence of Ce in Ce 2 Ni 12 P 5 determined based on the Ce L III absorption spectrum is ϑ eff ∼ 3.05. • Ce 2 Ni 12 P 5 has been prepared from the elements by arc-melting technique and subsequent annealing at 1070 K for 1500 h. • X-ray powder diffraction reveals Ce 2 Ni 12 P 5 to crystallize in a monoclinic La 2 Ni 12 P 5 structure type. • The studied compound belongs to the systems with strong electron-electron correlations. • External magnetic field enhances the decrease of the electrical resistance of Ce 2 Ni 12 P 5 with decreasing temperature. • The effective valence of the Ce atoms in Ce 2 Ni 12 P 5 was determined from the Ce L III absorption spectrum to be ϑ eff ∼ 3.05. [ABSTRACT FROM AUTHOR]

[Display omitted] • Phosphorus speciation in the native-iron bearing volcanics of Disko Island. • Reducing conditions and nonequilibrium leads to P compounds diversity. • Reactive phosphorus may have formed in crustal rocks of early Earth. Phosphorus is one of the key elements, which determined the emergence of primordial life on our planet. The source of prebiotic phosphorus was most likely to be easily soluble compounds containing phosphorus in the negative form of oxidation (e.g., phosphides). The present paper is the first thorough investigation of phosphide-bearing mineral assemblages confined to telluric (terrestrial) native iron from volcanic rocks of Disko Island, Greenland. Phosphorus speciation in given assemblages varies from the solid solution in native iron (up to 0.3 wt.% P), different phosphides – schreibersite Fe 3 P, nickelphosphide Ni 3 P, barringerite Fe 2 P, and phosphates, including fluorapatite, anhydrous Fe-Na phosphates, phosphoran olivine and pyroxene (up to 1 wt.% P). The diversity of observed phosphorus speciation can be explained by the steep changes of redox conditions during subsurface crystallization of iron-phosphide-bearing lavas. Based on the available data on likely redox conditions on the early Earth, we hypothesize that reactive prebiotic phosphorus may have originated from shallow crustal rocks. [ABSTRACT FROM AUTHOR]

The design of a highly efficient electrocatalyst for oxygen evolution reaction (OER) is of great significance to the clean energy conversion system. Herein, novel Mo-doped NiFe phosphide (Mo-NiFe-P) nanoflowers are developed as robust high-activity catalysts for OER via the phosphidation of MoO42− intercalated NiFe-layered double hydroxide (NiFe-LDH). The introduction of high valence Mo can significantly promote the catalytic activity of OER because of the strong electronic interactions with Ni and Fe. By tailoring the amount of molybdate intercalated into NiFe-LDH, the optimal phosphide shows outstanding overpotentials of 261 and 272 mV to drive current densities of 50 and 100 mA cm−2 in 1 mol L−1 KOH. This work demonstrates that the amount of molybdate influences the structure of phosphide prepared by the intercalated LDHs and also affects the electrocatalytic behavior. In addition, density functional theory (DFT) calculations show that introducing Mo could alter the intrinsic electronic structure of NiFe-P, which, in turn, could accelerate the reaction kinetics. This approach could be extended to the preparation of other cost-efficient phosphides for OER.

Metal phosphides with multi-element components and amorphous structure represent a novel kind of electrocatalysts for promising activity and durability towards the oxygen evolution reaction (OER). In this work, a two-step strategy, including alloying and phosphating processes, is reported to synthesize trimetallic amorphous PdCuNiP phosphide nanoparticles for efficient OER under alkaline conditions. The synergistic effect between Pd, Cu, Ni, and P elements, as well as the amorphous structure of the obtained PdCuNiP phosphide nanoparticles, would boost the intrinsic catalytic activity of Pd nanoparticles towards a wide range of reactions. These obtained trimetallic amorphous PdCuNiP phosphide nanoparticles exhibit long-term stability, nearly a 20-fold increase in mass activity toward OER compared with the initial Pd nanoparticles, and 223 mV lower in overpotential at 10 mA cm−2. This work not only provides a reliable synthetic strategy for multi-metallic phosphide nanoparticles, but also expands the potential applications of this promising class of multi-metallic amorphous phosphides.

In this paper, firstly, nickel foam (NF) was etched in HF at different conditions. Then, Ni2P was synthesized on the etched NF (Ni2P/NF). The results indicate the concentration of HF, temperature, and etching time could affect the performance of NF, while the Ni2P synthesized on the best NF has better catalytic performance and can be used as a bifunctional catalyst for both hydrogen evolution reaction (HER) and urea oxidation reaction (UOR). For the anodic UOR, it can reach 1.42 V at 100 mA·cm−2. While for the cathodic HER, the overpotential is 299 mV at 100 mA·cm−2. Thus, that nickel phosphate on etched NF has good catalytic performance and can be used as a new catalyst for the electrolytic water-urea system. [ABSTRACT FROM AUTHOR]

Nickolayite, FeMoP, is a new terrestrial phosphide structurally related to allabogdanite (high-pressure modification of (Fe,Ni)2P), and the meteoritic phosphides florenskyite, FeTiP and andreyivanovite, FeCrP. From the point of view of chemical composition, nickolayite is an Fe-analogue of monipite, MoNiP. The mineral was discovered in the Daba-Siwaqa complex, Central Jordan, a part of the pyrometamorphic Hatrurim Formation (the Mottled Zone), whose outcrops encompass a 150 × 200 km area around the Dead Sea in the Middle East. Nickolayite appears as an accessory phase in the fused clinopyroxene–plagioclase rocks texturally resembling gabbro–dolerite. The irregularly shaped grains of the mineral, up to 80 μm in size are associated with baryte, tridymite, chromite, hematite, pyrrhotite, fluorapatite, titanite and powellite. Macroscopically, nickolayite grains possess light-grey to greyish-white colour and metallic lustre. The mineral is ductile. The mean VHN hardness (50 g load) is 538 kg mm–2. The calculated density based on the empirical formula and the unit-cell parameters is 7.819 g cm–1. In reflected light, nickolayite has a white colour, with no bireflectance or pleochroism. The COM approved reflectance values [Rmax/Rmin (%), λ(nm)] are: 48.5/46.5 (470), 50.5/48.5 (546), 51.8/49.9 (589) and 53.9/52.0 (650). The chemical composition of the holotype crystal is (electron microprobe, average of 4 analyses, wt.%): Fe 32.21, Mo 47.06, Ni 3.69, Co 0.13, P 17.45, total 100.54, that corresponds to the empirical formula Fe1.00(Mo0.87Ni0.11Fe0.02)Σ1.00P1.00 and an ideal formula of FeMoP. Nickolayite is orthorhombic, space group Pnma, unit-cell parameters of holotype material are: a = 5.9519(5), b = 3.7070(3), c = 6.8465(6) Å, V = 151.06(2) Å3 and Z = 4. The crystal structure of holotype material was solved and refined to R1 = 0.0174 based on 251 unique observed reflections. The origin of the mineral is probably connected to the processes of co-reduction of molybdenum- and phosphorus-bearing minerals during high-temperature pyrometamorphic processes. [ABSTRACT FROM AUTHOR]

Orishchinite is a new terrestrial phosphide discovered in pyrometamorphic rocks of the Daba-Siwaqa combustion complex in West Jordan. The mineral occurs as an accessory phase in the fused clinopyroxene-plagioclase rock (paralava) texturally resembling gabbro-dolerite. Orishchinite forms resorbed equant grains up to 0.2 mm outrimmed with 0.1–0.2 thick zones of substituting murashkoite, FeP. Chemical composition (electron microprobe, wt%): Ni 38.49, Fe 22.38, Co 0.47, Mo 18.80, P 19.46, Total 99.60, corresponding to the empirical formula (Ni1.04Fe0.64Mo0.31Co0.01)Σ2.00P on the basis of 3 apfu. The simplified formula is (Ni,Fe,Mo)2P and the ideal one is Ni2P. Macroscopically, orishchinite grains have yellowish-white colour with metallic lustre. The mineral is brittle. In reflected light, orishchinite is yellowish-white and non-pleochroic. It is very weakly anisotropic (ΔR589 = 1.3%). Reflectance values for the wavelengths recommended by the Commission on Ore Mineralogy of the International Mineralogical Association are [Rmax/Rmin (%), λ (nm)]: 48.1/47.5, 470; 50.6/49.4, 546; 52.1/50.8, 589; 54.4/52.9.1, 650. The crystal structure was solved and refined to R1 = 0.016 based on 224 unique observed [I ≥ 2σ(I)] reflections. Orishchinite is orthorhombic, space group Pnma, a 5.8020(7), b 3.5933(4), c 6.7558(8) Å, V 140.85(3) Å3, Z = 4, Dx = 7.695 g cm-3. The strongest lines of the powder X-ray diffraction pattern [(d, Å) (I, %) (hkl)] are: 2.265(100)(112), 2.201(16)(202), 2.142(55)(211), 2.100(35)(103), 1.909(21)(013), 1.811(19)(113), 1.796(31)(020). Orishchinite is dimorphous with transjordanite (hexagonal Ni2P) and can be considered the Ni-dominant analogue of allabogdanite. [ABSTRACT FROM AUTHOR]

It is important to develop economical and durable electrocatalysts for sustainable energy conversion technology. However, the current catalysts still suffer from insufficient hydrogen adsorption energy. Herein, we report a kind of novel bi-phosphide catalyst through constructing heterogeneous structures and cation doping. The obtained sample delivers an outstanding hydrogen evolution reaction (HER) performance at all pH range. As oxygen evolution reaction (OER) electrocatalyst, Fe-CoP@Ni2P samples show an overpotential of 237 mV at 50 mA·cm−2 in alkaline solution. For electrolysis of water, Fe-CoP@Ni2P catalysts deliver a cell voltage of 1.59 V at 50 mA·cm−2 and long durability. Furthermore, density functional theory (DFT) calculation further confirms that the doped heterostructure promotes Gibbs free energy for hydrogen adsorption. And the significant increase in the density of total states (DOS) also enhances the catalytic activity of HER. [ABSTRACT FROM AUTHOR]

At present, it is very necessary to select and prepare suitable positive and negative electrode materials to fabricate high-performance asymmetric supercapacitors. Metal-organic frameworks (MOFs) have garnered significant attention in the energy storage field due to their high conductivity. As a branch, the zirconium organic framework (UIO-66) is a promising porous material due to its large specific surface area and abundant Zr centers. Graphene oxide (GO) and MXene are very suitable as substrate materials for conducting an MOF due to their abundant active sites and adjustable interlayer distance. The GO/MXene@NiZrP prepared through an in situ composite of GO and Mxene with the hydrothermal method and calcining method showed excellent electrochemical performance. Compared with the precursor UIO-66, the specific capacitance of the final product GO/MXene@NiZrP increases more than ten times, mainly because of its special layered porous structure, and GO/MXene@NiZrP has a larger specific surface area, pore volume, and surface defects caused by unstable Zr 4+ than those of UIO-66. Using GO/MXene@NiZrP as the positive electrode and biochar (BC) as the negative electrode, an asymmetric supercapacitor, BC//GO/MXene@NiZrP, is assembled. After 10,000 cycles at a current density of 10 A g -1 , the capacitance retention remains at 83.3%, showing excellent cycle stability.