146 results about "Double perovskite" patented technology

The present invention provides a material suitable for use in a solid oxide fuel cell, wherein the material is of an, optionally doped, double perovskite oxide material having the general formula (I): (Ln_aX_b)_e(Z¹_cZ²_d)_fO_g (I) wherein Ln is selected from Y, La and a Lanthanide series element, or a combination of these and X also represents an element occupying the A site of a perovskite oxide and is selected from Sr, Ca and Ba, and Z¹ and Z² represent different elements occupying the B site of a perovskite oxide and are selected from Cr, Mn, Mg and Fe, and wherein a has a value from 0 to 1, preferably 0.7 to 1.0, b has a value of from 1 to 0, preferably 0.3 to 0, and each of c and d has a value of from 0.25 to 0.75, provided that a+b has a value of 1, and c+d, has a value of 1, and wherein e has a value of from 0.8 to 1, wherein f has a value of from 0.8 to 1, and g has a value of from 2.5 to 3.2. Also provided are SOFCs having an electrode or functional layer of a material or containing a material of the invention, as well as mixed ionic/electronic conducting membranes suitable for use in a syngas reactor or oxygen separator, comprising a layer of a double perovskite material of the invention, and a method of oxidising a fuel in an SOFC having an anode of a double perovskite material of the invention.

The invention discloses double-perovskite structured red fluorescent powder as well as a preparation method and application thereof, belonging to the field of fluorescent materials. The chemical formula of the fluorescent powder can be shown as Ln2-xAMO6:xEu and meets the following conditions: Ln is one, two or three of La, Gd and Y; A is one, two or three of Li, Na and K; M is one, two or three of Sb, Nb and Ta; and Eu is a luminescent center and is doped in the Ln position and the doping value x is 0.01-1.0. The fluorescent powder disclosed by the invention can emit fluorescence of 570-640 nm under the excitation of a green light chip (528-533 nm), a blue light chip (460-470 nm) or a near-ultraviolet light chip (390-399 nm), and red fluorescence is of 600-620 nm. The fluorescent powder can be used for white LED (light-emitting diode) and related display and lighting devices, has a simple preparation process, stable chemical properties and excellent luminescent performance, and is ideal fluorescent powder used for white LED.

The present invention relates to a preparation method of titanium-containing double perovskite type methane combustion catalyst. The process is characterized in that a certain amount of butyl titanate is added into ethanol to produce white sediment; concentrated nitric acid is added until the sediment is totally dissolved and transparent solution is obtained; lanthanum nitrate and magnesium nitrate are weighed and dissolved in the deionized water and a certain amount of dextrose is added, thus completely forming composition solution; then gel is formed by constant-temperature stirring and evaporation; the gel obtained is dried and sintered at the temperature of 500 DEG C, 800 DEG C and 1,100 DEG C in the air for three hours to obtain the catalyst La2MgTiO6. The present invention is characterized in that the Sol-Gel Preparation Method with the dextrose as the complexing agent is adopted and the single-phase double layer perovskite type composite oxide catalyst is prepared at lower temperature. The preparation method is simple and low in cost. The catalyst used in methane catalytic combustion reaction has the characteristics of low initiation temperature and low whole transformation temperature.

The invention relates to double perovskite type inorganic nano fiber and a preparation method thereof and belongs to the field of inorganic nano fiber materials. The preparation method comprises the following steps: mixing polyvinylpyrrolidone with a solvent to obtain a spinning precursor solution, and performing electrostatic spinning, preoxidation and carbonization to the spinning precursor solution to obtain the double perovskite type inorganic nano fiber; the spinning precursor solution comprises the following components in mass percent: 10% to 20% of inorganic salt, 10% to 30% of polyvinylpyrrolidone and the balance of solvent, wherein the inorganic salt is the mixture of lanthanum salt, cobalt salt and metal salt III, the molar ratio of the lanthanum salt, the cobalt salt and the metal salt III is 2:1:1, and the metal salt III is nickel salt, ferric salt or manganese salt. The invention has the advantages that the preparation method is simple and easy to implement, the raw material consumption is low, the product purity is high, and the obtained double perovskite type inorganic nano fiber has a stable one-dimensional structure, is relatively high in draw ratio and uniform in diameter.

The invention belongs to the technical field of the semiconductor photoelectric detection, and specifically relates to a deep-ultraviolet detector based on a lead-free double-perovskite film, and a preparation. The structure is composed of a double-side polished Al2O3 substrate, n-type bandwidth gap electronic transmission layer, a Cs2AgBiBr6 light absorption layer and a contact electrode. On theone hand, the instability and the lead positioning and like adverse factors of the traditional perovskite structure are overcome; on the other hand, the fast separation and transmission of the photo-generated carrier can be realized by means of the energy band matching between the bandwidth gap electronic transmission layer and the Cs2AgBiBr6 light absorption layer, and the light detection range of the device can be extended to the deep ultraviolet region from the visible light. The preparation method of the device disclosed by the invention is simple and practical, and environment-friendly; the prepared photoelectric detector has high detection rate and response speed, and has very important application value.

The provided preparation method for a Sr2MWO6 (M = Fe or Mn) material comprises: using the Sr(NO3)2, Fe(NO3)3, Mn(NO3)4 and ammonium paratungstate as material, citric acid as complexant, and ethylene glycol as dispersant; reacting for 20-40h at 950-1150Deg to obtain the biperovskite-structure product. This invention uses sol-gel technique with low temperature and short time, removes the SrWO4 in solid phase reaction, and fit to large-scale production.

The invention provides a two-dimensional double perovskite material. The composition formula of the two-dimensional double perovskite material is AnMIIIMIX8, wherein A is organic amine; MIII is a trivalent metal element; MI is a monovalent metal element; and X is halogen. The two-dimensional double perovskite material has certain advantages of methylamine lead-iodine perovskite and lead-free double perovskite. The material is lead-free and environmentally friendly, has very good light stability and good chemical stability, and is unlikely to deteriorate in air. The material has a suitable andadjustable light absorption band gap, and more importantly can be used for preparing a film at a low temperature by a solution method. The advantages provide basis for the application of the materialin the photovoltaic fields such as solar cells, optical detectors and light-emitting diodes.

A superconducting article includes a substrate having a biaxially textured surface. A biaxially textured buffer layer, which can be a cap layer, is supported by the substrate. The buffer layer includes a double perovskite of the formula A₂B′B″O₆, where A is rare earth or alkaline earth metal and B′ and B″ are different transition metal cations. A biaxially textured superconductor layer is deposited so as to be supported by the buffer layer. A method of making a superconducting article is also disclosed.

The invention discloses a double-perovskite composite metal oxide catalyst and a preparation method and application thereof and belongs to the technical field of atmospheric pollution treatment. The condensed structural formula of the double-perovskite composite metal oxide catalyst is A2B2O6, wherein A is La, Sr or Ce, and B is Mn, Fe, Co, Cu or Ni. The double-perovskite composite metal oxide catalyst has the advantages that the catalyst is excellent in high temperature resistance, water resistance and chlorine resistance and applicable to effective degradation of CVOCs under an industrial high-temperature environment; the catalyst can achieve complete oxidization of industrial typical CVOCs (1,2-dichloroethane) under reaction temperature of 500-550 DEG C, reaction air speed of 20000-30000h<-1> and oxygen concentration of 10-20%; meanwhile, by regulating the loading capacity of transition metal oxide, the oxidizing efficiency of the catalyst can be increased effectively, and the selectivity of the reaction product CO2 can be increased greatly. The preparation method of the catalyst is simple, cheap in raw material and promising in industrial application prospect.

The present invention relates to a semiconductor device comprising a semiconducting material, wherein the semiconducting material comprises a compound comprising: (i) one or more first monocations [A]; (ii) one or more second monocations [B^I]; (iii) one or more trications [B^III]; and (iv) one or more halide anions [X]. The invention also relates to a process for producing a semiconductor device comprising said semiconducting material. Also described is a compound comprising: (i) one or more first monocations [A]; (ii) one or more second monocations [B^I] selected from Cu⁺, Ag⁺ and Au⁺; (iii) one or more trications [B^III]; and (iv) one or more halide anions [X].

The invention discloses a double perovskite single crystal photodetector and a preparation method thereof. The double perovskite single crystal photodetector comprises a substrate, wherein the substrate is provided with a double perovskite single crystal, electrodes and a silver glue in sequence, the two electrodes are respectively connected to a conductive gold wire, the double perovskite singlecrystal is in a double perovskite structure formed by adding different cations in a solution of the perovskite growth single crystal, and each of the added cations is one of methylamine ion (MA+), formamidine ion (FA+), phenethylamine ion (PEA+), NH4+, butylamine ion (Ba+), K+, Rb+ and Tl+. By doping different cations in the double perovskite single crystal photodetector, the carrier concentrationof the device is increased under illumination conditions, which leads to an increase in photocurrent and enhances the detection performance of the photodetector.

The invention relates to a double-perovskite structure catalyst material for a cathode of a lithium air battery and a preparation method of the catalyst material. The molecular formula of the catalyst material is AxA'(2-x)CryMo(2-y)O6, wherein A is one of Sr, Ca or Ba; A' is one of Sr, Ca, Ba, La, Ce, Pr, Nd, Sm, Eu or Gd; x is greater than 1 and less than 2; y is greater than 0 and less than 2. The preparation method comprises the following steps: obtaining xerogel by a sol-gel method; performing one-step or multi-step presintering on the obtained xerogel in an air atmosphere to obtain solid powder; and tableting the obtained solid powder, and roasting in a reducing atmosphere to obtain the double-perovskite structure material. Compared with the prior art, the catalyst disclosed by the invention is a single pure phase with stable physicochemical property; the preparation method is simple with good repeatability. The catalyst for a cathode of the lithium air battery has the advantages that the specific capacity of the battery is increased and the energy conversion efficiency of the battery is effectively improved. Moreover, the lithium air battery assembled by use of the material has a good cycle life.

The invention relates to a double-doped double perovskite red phosphor and a preparation method of the double-doped double perovskite red phosphor. The structure formula is shown as (AGd(1-x-y)EuxLny)MgMO6, wherein A is one of Na or K; Ln is one of Bi or Sm; M is at least one of W or Mo; x is greater than or equal to 0.05 and less than or equal to 0.5; and y is greater than or equal to 0.05 and less than or equal to 0.3. The double-doped double perovskite red phosphor is prepared through a sol-gel method; according to the invention, elements comprising Eu and Ln are doubly doped in matrixes of molybdate and tungstate of a double perovskite structure; the absorption width of Eu<3+> ion in a wave band of 0-400nm through the wideband absorption of Bi<3+> or Sm<3+> ion in a nearly ultraviolet region; and both the color purity and the luminous strength of the Eu<3+> ion are improved through an existing energy transfer process. A single-phase double perovskite oxide powder can be acquired by the preparation method under the conditions of low temperature and short insulation time; the mixture at an iron or atom level can be realized by activating ions by using rare earth; and the test period is short and the stability is good.

The invention relates to double-perovskite tungsten molybdate red fluorescent powder for a white light LED and a preparation method of the double-perovskite tungsten molybdate red fluorescent powder. The chemical expression of the red fluorescent powder is AA<II>1-xLi<+>B<II>O6:xEu<3+>, wherein Eu<3+> is an active ion doped to an A<II> site, and the doping amount x is more than or equal to 0.01 and less than or equal to 0.6; A is any one of or a combination of more of divalent alkaline earth metal ions Ca<2+>, Sr<2+> and Ba<2+>; A<II> is any one of or a combination of more of trivalent rare-earth ions La<3+>, Gd<3+>, Y<3+> and Sc<3+>; B<II> is any one of or a combination of W<6+> and Mo<6+>; and the red fluorescent powder is prepared by adopting a low-temperature combustion method. The double-perovskite tungsten molybdate red fluorescent powder disclosed by the invention can be efficiently excited by near ultraviolet and blue light chips, the luminous efficiency is improved, the preparation process is simple, and the synthesis temperature is low, so that the double-perovskite tungsten molybdate red fluorescent powder is ideal red fluorescent powder suitable for the white light LED.