8 results about "Pure crystal" patented technology

The invention discloses a method for realizing high-efficiency continuous synthesis of a pure-phase doped ternary precursor, and relates to the technical field of material preparation, and the method comprises the following steps: constructing a flow reaction chain for continuous wet synthesis of the ternary precursor, carrying out time development treatment on a migration process of metal ions from a feeding end to a nucleation interface in the flow reaction chain, and carrying out solid-liquid separation on the metal ions; and a potential evolution baseline is formed at the end of time expansion. By constructing a potential evolution baseline, a charge fluctuation early warning interval and a charge slow release channel, energy dynamic balance and early release of charge density waves in the metal ion migration process are achieved, crystal face orientation is stabilized, and a pure crystal phase is obtained. Meanwhile, the temperature and the pH value of the ion migration buffer zone and the rhythm of the complexing agent are cooperatively regulated and controlled, so that particles are uniformly distributed, doping is stable, and the consistency and the electrochemical performance of the product are remarkably improved.

The invention relates to the technical field of composite catalysts, in particular to a defect-state porous TiO2 catalyst as well as a preparation method and application thereof. The technical key points are as follows: the defect-state porous TiO2 catalyst is of a hexagonal hollow structure, the diameter is 150-250 nm, the hollow diameter is 40-60 nm, and the defect-state porous TiO2 catalyst is in an anatase crystal form and is used for catalyzing synthesis of polyethylene furandicarboxylate. According to the preparation method disclosed by the invention, a three-step core process of nano-scale silicalite-1 molecular sieve hard template synthesis, precise alkali etching and hydrogen atmosphere calcination is adopted, the anatase phase defect state porous TiO2 catalyst with a regular hexagonal hollow structure and a pure crystal form is successfully prepared, and deep synergy of structural design and catalytic performance is realized.

The application relates to the technical field of semiconductor photocatalysis and functional nanomaterials, and discloses a two-step hydrothermal method for synthesizing high-purity orthorhombic WO3 crystals, which comprises the following steps: preparation of a precursor solution, addition of a complexing agent, protonation reaction, hydrothermal treatment, product collection and washing, drying treatment and calcination treatment; the two-step hydrothermal method uses concentrated sulfuric acid as a protonation reaction medium, avoids the introduction of an organic carbon additive, realizes accurate control of crystal nucleation and growth kinetics in the hydrothermal reaction process, promotes the formation of an orthorhombic structure, and obtains WO3 crystals with a cubic morphology, pure crystal form and inhibited surface defects; meanwhile, the addition of citric acid as a complexing agent can stabilize tungsten species and ensure uniform distribution of the precursor, and improves the integrity and uniformity of the crystal structure.

This invention belongs to the field of crystal material preparation technology and discloses a method for growing large-size, high-purity PMN single crystals using a top-seeded crystal growth method. It employs a gradient molten salt single crystal furnace equipped with a hollow oxygen-bearing seed crystal rod and a bidirectional rotation mechanism. The seed crystal rod and crucible rotate in opposite directions. By optimizing the composite flux ratio and identifying the drawbacks of excessively high / low ratios, adopting an extremely low cooling rate adapted to the temperature sensitivity of PMN, and designing a staged speed control strategy that precisely correlates crystal outline size with rotation speed, combined with temperature field optimization due to the opposite rotation of the seed crystal and crucible, and nucleation control through oxygen-bearing at the seed crystal to create a cold end, the crystal outline size is observed at high temperature, and process parameters are adjusted in real time to achieve high-purity growth of large-size PMN single crystals. The final obtained PMN single crystals are verified by XRD, scanning electron microscopy, EDS energy dispersive spectroscopy, and dielectric temperature spectroscopy to be free of impurities and have a pure crystal form. The single crystal size breaks through the large-size level and has good formability, meeting the application requirements of devices in the fields of electronics, piezoelectrics, and optics.

The utility model relates to the technical field of composite sleeves, in particular to an environment-friendly pure crystal composite sleeve with a pre-positioning structure, which comprises a sleeve and an inner pipe, and further comprises a lantern ring, a positioning locking component and a sliding pre-positioning component, positioning and locking assemblies which are symmetrically distributed up and down are fixedly connected in the sleeve ring, each positioning and locking assembly comprises an arc-shaped positioning seat, an insertion hole is formed in each arc-shaped positioning seat, a positioning and locking insertion rod is inserted in each insertion hole, and a pulling plate is fixedly connected to the end, away from the sleeve, of each positioning and locking insertion rod; the outer side of the inner pipe is slidably connected with a sliding pre-positioning assembly corresponding to the positioning locking assembly, and the sliding pre-positioning assembly comprises a pre-positioning connecting block and a sliding block; by arranging the pre-positioning device, convenient sleeving and positioning of the composite sleeve and the pipe are achieved, the problem that positioning is difficult due to the fact that the positions of the sliding blocks on the two sides are inconsistent is solved, and the pre-positioning structure is prevented from loosening due to the fact that the pre-positioning device is further provided with the locking mechanism.

The invention belongs to the technical field of electrochemical separation materials, and particularly discloses a zeta-V2O5 material with a tunnel structure as well as a preparation method and application of the zeta-V2O5 material. According to the invention, alpha-V2O5 and silver salt are used as precursors, and zeta-V2O5 with a one-dimensional tunnel structure is successfully constructed through a two-step hydrothermal method. The preparation method is simple, the raw materials are easy to obtain, the reaction conditions are mild, the crystal structure of the product is stable, the purity is high, and the problem that pure-phase zeta-V2O5 is difficult to obtain through a traditional method is solved. The prepared zeta-V2O5 has specific interstitial sites and shows excellent selective insertion capacity for lithium ions, the problems that a traditional lithium isotope separation process is high in energy consumption, large in pollution and the like are solved through a method for efficiently separating Li isotopes through a mixed capacitive deionization technology, and a new way is provided for obtaining nuclear fusion fuel 6Li in a green and low-carbon mode.

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of a D-pi-A type organic second-order nonlinear optical compound. The preparation method comprises the following steps: mixing a ketone compound and an oxide, and heating and refluxing for a period of time under a stirring condition; after the reaction is finished, cooling reaction liquid to room temperature, and adding a good solvent to dissolve a solid substance obtained by the reaction; and slowly volatilizing the obtained clear solution at room temperature for a period of time to obtain a pure crystal of a target product. The preparation method provided by the invention has the advantages of simple reaction device, mild reaction conditions, easily available raw materials, low cost and easy separation of target products. Meanwhile, the D-pi-A type organic compound prepared by the preparation method disclosed by the invention has a nonlinear optical property, and shows a second harmonic phenomenon under near-infrared light, and the highest intensity is about 2.7 times of that of KDP (potassium dihydrogen phosphate). The method is of great significance to the structure-activity relationship and the practical application research of the second-order organic nonlinear optical crystal material.

The invention relates to the technical field of molecular sieves, and discloses a short-cylinder-like ERI structure molecular sieve, a preparation method and application thereof, and a method for catalytic reduction of nitric oxide by ammonia gas, the microstructure of the molecular sieve is a short-cylinder-like shape formed by ordered aggregation of short-rod small crystal grains, and the ratio of the diameter to the thickness of the short-cylinder-like shape is not less than 3; the size of the short-rod small crystal grains in at least one dimension is less than 0.4 [mu] m. The molecular sieve is small in grain size, pure in crystal phase, good in diffusion performance and high in low-temperature activity, and is particularly suitable for being used as a gas adsorption separating agent or a catalyst component to be applied to carbon dioxide adsorption separation, synthesis gas, olefin preparation through methanol conversion, ammonia gas catalytic reduction of nitric oxide and other reactions; the catalyst is especially suitable for being used as a catalyst to be applied to ammonia gas catalytic reduction of nitric oxide, and the conversion rate of NO after reaction is high under the low-temperature condition.