Oxyphosphide Research Articles

Unusual Activity of Rationally Designed Cobalt Phosphide/Oxide Heterostructure Composite for Hydrogen Production in Alkaline Medium.

Design and development of an efficient, nonprecious catalyst with structural features and functionality necessary for driving the hydrogen evolution reaction (HER) in an alkaline medium remain a formidable challenge. At the root of the functional limitation is the inability to tune the active catalytic sites while overcoming the poor reaction kinetics observed under basic conditions. Herein, we report a facile approach to enable the selective design of an electrochemically efficient cobalt phosphide oxide composite catalyst on carbon cloth (CoP-CoxOy/CC), with good activity and durability toward HER in alkaline medium (η10 = −43 mV). Theoretical studies revealed that the redistribution of electrons at laterally dispersed Co phosphide/oxide interfaces gives rise to a synergistic effect in the heterostructured composite, by which various Co oxide phases initiate the dissociation of the alkaline water molecule. Meanwhile, the highly active CoP further facilitates the adsorption–desorption process of water electrolysis, leading to extremely high HER activity.

Ditopic Phosphide Oxide Group: A Rigidifying Lewis Base to Switch Luminescence and Reactivity of a Disilver Complex.

Heterodentate phosphines containing anionic organophosphorus groups remain virtually unexplored ligands in the coordination chemistry of coinage metals. A hybrid phosphine-phosphine oxide (o-Ph2PC6H4)2P(O)H (HP3O) readily forms the disilver complex [Ag2(P3O)2] (1) upon deprotonation of the (O)P-H fragment. Due to the electron-rich nature, the anionic phosphide oxide unit in 1 takes part in efficient intermolecular hydrogen bonding, which has an unusual and remarkably strong impact on the photoluminescence of 1, changing the emission from red (644 nm) to green-yellow (539 nm) in the solid. The basicity of the R2(O)P- group and its affinity for both inter- and intramolecular donor-acceptor interactions allow converting 1 into hydrohalogenated (2, 3) and boronated (4) derivatives, which reveal a gradual hypsochromic shift of luminescence, reaching the wavelength of 489 nm. Systematic variable-temperature analysis of the excited state properties suggests that thermally activated delayed fluorescence is involved in the emission process. The long-lived excited states for 1-4, the energy of which is largely regulated by means of the phosphide oxide unit, are potentially suitable for triplet energy transfer photocatalysis. With the highest T1 energy among 1-4, complex 4 demonstrates excellent photocatalytic activity in a [2+2] cycloaddition reaction, which has been realized for the first time for silver(I) compounds.

Synthesis of Al doped CoP2/rGO composite and its high electrocatalytic activity for hydrogen evolution reaction

A series of Al-doped CoP2/rGO composites have been fabricated by in-situ precipitation and phosphorization protocol. The well-ordered arrangement and widely adjustable mole ratio of cations within Co–Al layered double hydroxide (CoAl-LDH) make it suitable as a precursor for phosphiding and generating evenly dispersed Al element within CoP2 structure. The effect of Al doping content on the catalytic activities for hydrogen evolution reaction thus could be discussed in detail. Electrocatalytic performance indicates that the doping of Al element within CoP2 structure could efficiently prevent the oxidation of phosphide on the surface, and thus resulting in the high electrocatalytic activity for hydrogen evolution reaction (HER). Among all the Al-doped CoP2/rGO materials, the composite with the Co/Al mole ratio of 2/1 presents the highest HER activity and stability whatever under acidic or basic reaction conditions, which could be comparable to the most reported HER electrocatalysts and even the commercial 20% Pt/C. At the current density of −10 ​mA ​cm−2 in 0.5 ​M ​H2SO4, the overpotential is only 59 ​mV with a Tafel slope of 73.2 ​mV dec−1. Interestingly, the Al content could be dissolved under basic media and resulting in a porous structured electrode. Only the overpotential of 60 ​mV is needed to get the current density of −10 ​mA ​cm−2 in 1 ​M KOH.

Activation of film growth on indium phosphide by pulsed photon treatment

Photon activation of various physicochemical processes by the radiation of powerful pulsed xenon lamps (radiation range of 0.2-1.2 µm) is one of the promising areas of material science. The aim of this study was to determine the effect of preoxidative pulsed photon treatment on the process of thermal oxidation of indium phosphide with a nanosized layer of V2O5 on the surface, as well as its effect on the composition and morphology of the formed films. We determined the optimal mode of pre-oxidative pulsed photon treatment of magnetron-formed V2O5/InP heterostructures with a radiation density of 15 J/cm2. By laser and spectral ellipsometry methods, photon activation of V2O5/InP before thermal oxidation was found to increase the thickness of the formed films practically twofold. X-ray diffraction analysis confirms the intensification of the phosphate formation process. The morphological characteristics of the films were determined by atomic force microscopy.Pre-oxidative pulsed photon treatment with an optimal radiation density of 15 J/cm2 activates the thermal oxidation of V2O5/InP heterostructures. It is associated with the formation of new active centres and accelerated rearrangement of chemical bonds in the intermediate complexes of the V2O5 catalyst with semiconductor components

Воздействие некоторых сложных хемостимуляторов и модификаторов на термооксидирование InP

Воздействие некоторых сложных хемостимуляторов и модификаторов на термооксидирование InP

Spontaneous Generation of H2O2 and Hydroxyl Radical through O2 Reduction on Copper Phosphide under Ambient Aqueous Condition.

Copper phosphide (Cu xP) was synthesized and tested for its reactivity for generating H2O2 through spontaneous reduction of dioxygen under ambient aqueous condition. The in situ generated H2O2 was subsequently decomposed to generate OH radicals, which enabled the degradation of organic compounds in water. The oxygen reduction reaction proceeded along with the concurrent oxidation of phosphide to phosphate, then copper ions and phosphate ions were dissolved out during the reaction. The reactivity of Cu xP was gradually reduced during 10 cycles with consuming 8.7 mg of Cu xP for the successive removal of 17 μmol 4-chlorophenol. CoP which was compared as a control sample under the same experimental condition also produced H2O2 through activating dioxygen but did not degrade organic compounds at all. The electrochemical analysis for the electron transfers on Cu xP and CoP showed that the number of electrons transferred to O2 is 3 and 2, respectively, which explains why OH radical is generated on Cu xP, not on CoP. The Cu+ species generated on the Cu xP surface can participate in Fenton-like reaction with in situ generated H2O2. Cu xP is proposed as a solid reagent that can activate dioxygen to generate reactive oxygen species in ambient aqueous condition, which is more facile to handle and store than liquid/gas reagents (e.g., H2O2, Cl2, O3).

Designing Hybrid NiP2/NiO Nanorod Arrays for Efficient Alkaline Hydrogen Evolution.

Transition-metal phosphides (TMPs) have lately drawn intensive attention because of their noble metal-free properties and high catalytic activities for the hydrogen evolution reaction (HER). The current research mainly focuses on the development of TMPs toward the HER in acidic solutions; however, less efforts have been directed to specifically design TMPs for alkaline HER. Here, we design a new bi-functional metal phosphide-oxide catalyst to facilitate the overall multistep HER process in alkaline environments. In this new catalytic system, oxygen-vacancy-rich NiO provides abundant active sites for dissociation of water, and the negatively charged P species in NiP2 facilitate adsorption of hydrogen intermediates. The resulting hybrid NiP2/NiO NRs show excellent alkaline HER catalytic activity and stability. Our work demonstrates that it is highly promising to engineer multiple components in hybrid catalytic systems to enhance the overall reaction kinetics and thus achieve improvements in catalytic performance.

Spectroscopic properties of MZnPO (M=Gd, Y) polycrystals doped with Nd3+ ions

MZnPO:Nd3+ (M=Gd, Y) phosphide oxides were synthesized by using the solid state reaction method. Crystal structures have been confirmed with the X-ray powder diffraction. The MZnPO crystals possess trigonal structure with a R3m space group. In these compounds, the phosphate ions (P3-) create ligands, like the oxygen ions. The M-O and Zn-P bonds are covalent.The absorption, FTIR and emission spectra, as well as the luminescence decay curves measurements were performed. Stark energy levels of the Nd3+ ions were obtained from the absorption and emission spectra. The spectroscopic quality parameter and the luminescence branching ratio of the neodymium(III) ions were estimated. The investigated crystals might find applications as the down-shifting materials, to enhance the yield of silicon solar cells.

On the thermal oxidation of V x O y –InP heterostructures formed by the centrifugation of vanadium(V) oxide gel

The optimal mode for the application of a nanoscale layer of vanadium-pentoxide gel on the surface of indium phosphide by centrifugation is determined via spectroscopic ellipsometry and atomic-force microscopy. By oxidizing the formed VxOy—InP heterostructures, films are obtained with a grain structure, with the height of the relief not exceeding 70 nm. The presence of incompletely oxidized chemostimulator components (VO2, V2O3) in the films and the presence of InVO4, which binds the V2O5 chemostimulator and thereby blocks the regeneration cycle of V+5 ↔ V+4, suggest implementation of the transit mechanism of the chemostimulated oxidation of indium phosphide. The data of spectroscopic ellipsometry indicate incomplete kinetic blocking of the diffusion of indium into the films upon oxidation.

La3Cu4P4O2 and La5Cu4P4O4Cl2: synthesis, structure and 31P solid state NMR spectroscopy

Abstract The phosphide oxides La3Cu4P4O2 and La5Cu4 P4O4Cl2 were synthesized from lanthanum, copper(I) oxide, red phosphorus, and lanthanum(III) chloride through a ceramic technique. Single crystals can be grown in a NaCl/KCl flux. Both structures were refined from single crystal X-ray diffractometer data: I4/mmm, a = 403.89(4), c = 2681.7(3) pm, wR2 = 0.0660, 269 F2 values, 19 variables for La3Cu4P4O2 and a = 407.52(5), c = 4056.8(7) pm, wR2 = 0.0905, 426 F2 values, 27 variables for La5Cu4P4O4Cl2. Refinement of the occupancy parameters revealed full occupancy for the oxygen sites in both compounds. The structures are composed of cationic (La2O2)2+ layers and covalently bonded (Cu4P4)5– polyanionic layers with metallic characteristics, and an additional La3+ between two adjacent (Cu4P4)5– layers. The structure of La5Cu4P4O4Cl2 comprises two additional LaOCl slabs per unit cell. Temperature-dependent magnetic susceptibility studies revealed Pauli paramagnetism. The phosphide substructure of La3Cu4P4O2 was studied by 31P solid state NMR spectroscopy. By using a suitable dipolar re-coupling approach the two distinct resonances belonging to the P2 4– and the P3– units could be identified.

Spectroscopic properties of LaZnPO polycrystals doped with Nd3+ ions

LaZnPO phosphide oxide was synthesized by a solid state reaction. The crystal structure has been confirmed using the X-Ray Powder Diffraction. LaZnPO possesses a tetragonal crystal structure with a space group P4/nmm. The absorption, FTIR, Raman and luminescence spectra have been measured and analyzed. For the neodymium(III) ions the spectroscopic quality parameter and the luminescence branching ratio were estimated from the emission spectra. The investigated crystals may find applications as a down-shifting material, to enhance the yield of solar cells.

Catalytic method of synthesis of phosphorus acids esters from zinc phosphide and alcohol

Ecologically safe effective catalytic method for preparing phosphorous and phosphoric acid esters by oxidation of zinc phosphide with oxygen in the solution of copper(II) halides in butanol at 50–70°C is developed. It is found that in the presence of Cu(II) chloride a mixture of dibutyl hydrogen phosphite and tributyl phosphate is formed, while at the catalysis with Cu(II) bromide tributyl phosphate is mainly obtained. Promoting action of hydrogen chloride on the reaction rate and yield of organophosphorus compounds is established. Optimal reaction conditions are found and redox mechanism of catalytic process is assumed.

Chelating Assistance of P–C and P–H Bond Activation at Palladium and Nickel: Straightforward Access to Diverse Pincer Complexes from a Diphosphine–Phosphine Oxide

The diphosphine–phosphine oxide (DPPO) {[o-i-Pr2P-(C6H4)]2P(O)Ph} (1) reacts with [Ni(cod)2] (cod = 1,4-cyclooctadiene) to give the diphosphine–phosphide oxide κP,P(O),P pincer complex 3. According to DFT calculations, the Ph–P(O) bond activation involves a three-center P,Cipso,Ni transition state. Reaction of the DPPO ligand 1 with [(nbd)Pd(ma)] (nbd = 2,5-norbornadiene and ma = maleic anhydride) affords the [(DPPO)Pd(ma)] complex 4. Upon heating, the ma coligand is displaced and the κP,P(O),P palladium pincer complex 2 is obtained. The dinuclear complex {(DPPO)[Pd(ma)]2} (6) has also been authenticated. X-ray diffraction analysis showed an original situation in which the oxygen atom of the central phosphine oxide moiety bridges the two palladium centers. Addition of trifluoromethanesulfonic acid to DPPO 1 affords the trifunctional phosphine–phosphine oxide–phosphonium derivative 7. Upon reaction with [Pd2(dba)3], the palladium hydride κP,O(P),P pincer complex 8 is cleanly formed as the result of P+–H bo...

Phosphide Oxides RE2AuP2O (RE = La, Ce, Pr, Nd): Synthesis, Structure, Chemical Bonding, Magnetism, and 31P and 139La Solid State NMR

Polycrystalline samples of the phosphide oxides RE(2)AuP(2)O (RE = La, Ce, Pr, Nd) were obtained from mixtures of the rare earth elements, binary rare earth oxides, gold powder, and red phosphorus in sealed silica tubes. Small single crystals were grown in NaCl/KCl fluxes. The samples were studied by powder X-ray diffraction, and the structures were refined from single crystal diffractometer data: La(2)AuP(2)O type, space group C2/m, a = 1515.2(4), b = 424.63(8), c = 999.2(2) pm, β = 130.90(2)°, wR2 = 0.0410, 1050 F(2) values for Ce(2)AuP(2)O, and a = 1503.6(4), b = 422.77(8), c = 993.0(2) pm, β = 130.88(2)°, wR2 = 0.0401, 1037 F(2) values for Pr(2)AuP(2)O, and a = 1501.87(5), b = 420.85(5), c = 990.3(3) pm, β = 131.12(1)°, wR2 = 0.0944, 1143 F(2) values for Nd(2)AuP(2)O with 38 variables per refinement. The structures are composed of [RE(2)O](4+) polycationic chains of cis-edge-sharing ORE(4/2) tetrahedra and polyanionic strands [AuP(2)](4-), which contain gold in almost trigonal-planar phosphorus coordination by P(3-) and P(2)(4-) entities. The isolated phosphorus atoms and the P(2) pairs in La(2)AuP(2)O could clearly be distinguished by (31)P solid state NMR spectroscopy and assigned on the basis of a double quantum NMR technique. Also, the two crystallographically inequivalent La sites could be distinguished by static (139)La NMR in conjunction with theoretical electric field gradient calculations. Temperature-dependent magnetic susceptibility measurements show diamagnetic behavior for La(2)AuP(2)O. Ce(2)AuP(2)O and Pr(2)AuP(2)O are Curie-Weiss paramagnets with experimental magnetic moments of 2.35 and 3.48 μ(B) per rare earth atom, respectively. Their solid state (31)P MAS NMR spectra are strongly influenced by paramagnetic interactions. Ce(2)AuP(2)O orders antiferromagnetically at 13.1(5) K and shows a metamagnetic transition at 11.5 kOe. Pr(2)AuP(2)O orders ferromagnetically at 7.0 K.

A Further Extension of Pnictide Oxide Chemistry – Synthesis and Structure of La2AuP2O

AbstractThe phosphide oxide La2AuP2O was synthesized from lanthanum filings, dried La2O3, gold pieces, and ground red phosphorus in the ideal 1.33:0.33:1:2 ratio in an evacuated silica tube at 1473 K. Small single crystals were obtained by recrystallization in a NaCl/KCl flux. The structure was determined on the basis of single‐crystal X‐ray diffractometer data: new type, C2/m, a = 1537.3(3), b = 427.39(8), c = 1009.2(2) pm, β = 131.02(1) °, wR2 = 0.046, 1102 F2 values, 38 variables. La2AuP2O contains two striking structural motifs: The oxygen atoms are located in La4 tetrahedra. The latter are cis‐edge‐shared forming polymeric cationic [La2O]4+ chains. These cationic units are separated and charge‐balanced by [AuP2]4– polyanions which have monovalent gold in distorted trigonal planar phosphorus coordination. Two crystallographically independent phosphorus sites occur in the polyanion, i.e. isolated P3– besides dumb‐bells P24– (P2–P2 223 pm). La2AuP2O, which crystallizes in the form of ruby red transparent crystals, is an electron precise phosphide oxide (4La3+)(2Au+)(2P3–)(P24–)(2O2–).

Synthesis and catalytic performance of V2O5 nanoislands produced on the surface of InP crystals by electroexplosion

We report the deposition of chemostimulator nanoislands on the surface of indium phosphide by an electroexplosion process and the effect of experimental conditions (ambient composition, pressure, and source-substrate distance) on their size distribution and surface density. Vanadium oxide and vanadium islands are shown to have a catalytic effect on the surface oxidation of indium phosphide, ensuring one of the most effective interactions between a chemostimulator and a III–V semiconductor in an oxidizing atmosphere.

Avaliação de agente de ligação aziridínico por meio de técnicas de análises química e instrumental

A new method using wet chemistry and instrumental analysis has been developed for evaluating the ring-opening of aziridine tris [1-(2 methyl) aziridinyl] phosphide oxide (MAPO) of the bonding agent used in composite propellant. A reduction was observed in the intensity absorption bands in 1400 and 1040 cmˉ ¹ , characteristic of aziridinic ring. It was also observed, in some cases, that when the number of open aziridinyl ring increases, the NH band in the range 3400-3300 cmˉ ¹ , that appears with ring-opening, is located in the region of lower wave numbers. The study of the synthesis of MAPO derivative indicated side reactions such as homopolymerization of rings and also, with secondary hydroxyl of the 12-hydroxy stearic acid and probable humidity existent in the original sample.

ChemInform Abstract: ZrCuSiAs‐Type Phosphide Oxides: TbRuPO, DyRuPO, the Series LnOsPO (Ln: La, Ce, Pr, Nd, Sm), and ThAgPO.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ZrCuSiAs-type Phosphide Oxides: TbRuPO, DyRuPO, the Series LnOsPO (Ln = La, Ce, Pr, Nd, Sm), and ThAgPO

The title compounds were prepared by solid-state reactions and via tin and NaCl/KCl fluxes. They crystallize with the tetragonal ZrCuSiAs-type structure (P4/nmm, Z = 2), which was refined from single-crystal X-ray data of PrOsPO (a = 402.1(1), c = 824.0(1) pm, wR2 = 0.0490, 365 F2) and ThAgPO (a = 396.1(1), c = 877.8(1) pm, wR2 = 0.0307, 314 F2). They belong to a large family of isotypic compounds, of which several, mainly fluorine doped, iron containing compounds LnFeAsO1-xFx were discovered to be superconducting with relatively high transition temperatures only recently in other laboratories. Chemical bonding in these compounds is briefly discussed, and the importance of the weakly bonding Fe-Fe interactions for the phase transitions and the superconductivity is emphasized from the viewpoint of structural chemistry. A brief account of the history of the preparation of these compounds in our laboratory is given. Originally many of these compounds were obtained only in small amounts as byproducts in the course of the preparation of ternaries.

Magnetic, Optical, and Electronic Properties of the Phosphide Oxides REZnPO (RE = Y, La–Nd, Sm, Gd, Dy, Ho)

AbstractWell‐shaped yellow to red transparent single crystals of the phosphide oxides REZnPO (RE = Y, La–Nd, Sm, Gd, Dy, Ho) were synthesized from the elements and ZnO in NaCl/KCl fluxes in sealed silica ampoules. Four structures (NdZnPO type, R3m) were refined from single crystal X‐ray diffractometer data: a = 388.5(2), c = 3032(1) pm, wR2 = 0.0380, 360 F2 values for YZnPO, a = 394.6(2), c = 3071(1) pm, wR2 = 0.0587, 226 F2 values for SmZnPO, a = 392.2(2), c = 3056(1) pm, wR2 = 0.0262, 462 F2 values for GdZnPO, and a = 389.33(6), c = 3030.5(4) pm, wR2 = 0.0453, 217 F2 values for DyZnPO each with 14 variables per refinement. The structures are composed of alternate stacks of (RE3+O2−) and (Zn2+P3−) layers with covalent RE–O and ZñP bonding within and weak ionic bonding between the layers. The zinc and oxygen atoms have slightly distorted tetrahedral coordination by atoms of phosphorus and the rare earth element, respectively. According to the electron precise formulation RE3+Zn2+P3−O2−, these pnictide oxides are transparent in visible light. Susceptibility measurements on β‐CeZnPO, β‐PrZnPO, and GdZnPO reveal Curie‐Weiss paramagnetism with experimental magnetic moments of 2.31, 3.60, and 7.72 μB/RE atoms, respectively. β‐CeZnPO and β‐PrZnPO show antiferromagnetic order with Néel temperatures of 7.4 (Ce) and 2.2 (Pr) K. GdZnPO shows no magnetic ordering down to 2 K. Single crystal absorption spectra measured for REZnPO (RE = Y, La, Pr, Nd, Sm, Dy) in the NIR‐Vis region reveal unexpected variations for the optical band gap of these phosphide oxides. For RE = Pr, Nd, Sm, Dy, Ho f‐f electronic transitions with nicely resolved ligand‐field splittings are observed in the range 6000–20000 cm−1. DFT band structure calculations show similarity between the valence bands of tetragonal and rhombohedral REZnPO as they possess mainly P‐3p character. In both cases, the conduction bands have mainly Zn‐4s character, but a significant contribution of RE‐5d occurs in rhombohedral REZnPO, which is responsible for a smaller optical band gap for the latter compounds. Variations of the energy gaps of tetragonal REZnPO can be explained by hybridization of Zn‐4s + RE‐5d + RE‐4f orbitals for the conduction band. DFT volume optimizations of α‐ and β‐PrZnPO show β‐PrZnPO to be more stable by 10.7 kJ mol−1.