Technology for templet-free low-temperature preparation of porous boron nitride in one-step method

Abstract

The invention discloses a technology for the templet-free low-temperature preparation of porous boron nitride in a one-step method. In the technology, sodium borohydride or potassium borohydride is used as a boron source, urea or thiourea or aminothiourea is used as a nitrogen source, the boron source and the nitrogen source are proportionally weighed, are heated to 500 to 600 DEG C in a reaction kettle after being mixed evenly, and react, the mixture is naturally cooled to room temperature after heat preservation for 5 to 10 hours, and finally, the porous boron nitride is prepared by impurity removal and drying. The preparation technology has low price of a reactant, low reaction temperature, short reaction time, energy saving, simple operation, good repeatability and no pollution and is beneficial to the mass production of the porous boron nitride, a templet is not used in the reaction process, a residual reactant and a reaction byproduct are easy to remove, and the porous boron nitride has high yield and higher thermal stability.

Description

technical field [0001] The invention relates to a one-step technology for preparing porous boron nitride at low temperature without a template, and belongs to the technical field of inorganic non-metallic materials. Background technique [0002] Porous materials are an important class of materials, which can be widely used in catalyst supports, chemical filtration purification, organic separation, gas adsorbents, optoelectronic devices and other fields. Commonly used porous oxide supports, such as alumina, silica and zeolite, have poor thermal conductivity and are easily affected by water vapor, while porous carbon supports have high porosity, large specific surface area, excellent adsorption performance and high The surface is reactive, but once the use temperature exceeds 250°C, oxidation or even combustion will occur, so it can only be used at low temperatures. [0003] Hexagonal boron nitride has a structure similar to that of graphite. It has high thermal and chemical ...

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Problems solved by technology

The existing porous boron nitride preparation technology mainly includes: (1) template method; (2) self-propagating high temperature synthesis method; (3) aerosol synthesis method; (4) organic vacuum cracking method; (5) activated carbon template substitution method (6) BBr3, NH4Cl and Al powder reaction method, wherein the template method is the most widely used method for preparing porous boron nitride. It needs to pre-process the template, and finally remove the template. Not only the process is complicated, but also the reaction temperature is high; BBr 3 , NH4Cl and Al powder reaction method to prepare porous boron nitride although the temperature is low (500 ℃), but BBr 3 High price, easy hydrolysis and strong corrosion; other porous boron nitride preparation methods need to be carried out at high temperature and take a long time

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