Preparation method for chromium oxide nanometer materials

Abstract

The invention relates to a preparation method for chromium oxide (Cr2O3) nanometer materials, belonging to the technical field of inorganic material preparation. The preparation method comprises the steps: by taking chromic nitrate as raw materials, firstly carrying out hydrolysis to the chromic nitrate to generate hydrated chromium oxide nano particles through hydrothermal reaction under neutral or acidic conditions, and then the hydrated chromium oxide nano particles is performed with thermal calcination treatment so as to be crystallized into chromium oxide nanometer materials. According to the preparation method, the raw materials are non-toxic and harmless, no reducing agent, surface active agent or precipitating agent are needed, and the prepared nanometer chromium oxide has high purity, good specific surface area and excellent thermal stability. The particle size distribution is even, the chromium oxide nano particles with different particle sizes ranging from 20nm to 200nm can be obtained through simply regulating the acidity or calcination temperature of experiments. The method has low cost, is simple in production technique and easy for industrial large-scale production, and has no generation of chromium-containing wastes in the whole technique, thereby being an environment-friendly and clean method for preparing chromium oxide.

Description

technical field [0001] The invention belongs to the technical field of preparation of inorganic materials, in particular to a chromium oxide (Cr 2 o 3 ) Preparation methods of nanomaterials. Background technique [0002] Nano-chromium oxide is an important inorganic powder, widely used in catalysis, hydrogen absorption and storage, high-density chromium oxide materials, optical materials, battery cathode materials, ceramics, advanced transparent pigments, functional coatings, organic synthesis and other fields. At present, the preparation method of nano-chromium oxide is mainly the liquid phase preparation method, and the liquid phase preparation method mainly includes the following three methods: sol-gel method, sodium chromate acid reduction method and chromic anhydride (CrO 3 ) reduction method. The sol-gel method requires strong mechanical stirring and the addition of relatively expensive surfactants. The disadvantage of this method is that the concentration of reacta...

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Problems solved by technology

The sol-gel method requires strong mechanical stirring and the addition of relatively expensive surfactants. The disadvantage of this method is that the concentration of reactants is generally relatively low. Strong mechanical stirring leads to high energy consumption and high cost of surfactants.

The sodium chromate reduction method is to obtain Cr by reducing it under acidic conditions. 3+ , then add surfactant and alkaline precipitant to get Cr(OH) 3 , and finally calcined to obtain nano-chromium oxide. This method is complex in process and needs to add surfactants, adjust acidity, etc. There are many parameters that need to be controlled, the process is complex, and the cost is high.

Chromic anhydride (CrO 3 ) reduction method is to use alcohols, aldehydes or other substances for hydrothermal reduction reaction, but the raw materials are highly toxic, and it is easy to introduce impurity elements and residual CrO 3 , it is difficult to obtain high-quality products. In addition, there are non-liquid phase methods, such as vapor deposition method, microwave plasma method, laser-induced pyrolysis method, etc., but the output is small, the preparation equipment is expensive, and it is not suitable for large-scale production

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