A kind of preparation method of high-purity lanthanum stannate nano powder

Abstract

The invention relates to preparation of nano powder, and aims to provide a preparation method of high-purity lanthanum stannate nano powder. The method comprises the following steps: respectively preparing an oxalic acid dihydrate water solution and a lanthanum nitrate-tin tetrachloride pentahydrate water solution; dropwisely adding the lanthanum nitrate-tin tetrachloride pentahydrate water solution into the oxalic acid dihydrate water solution to form a uniform transparent solution; adding polyvinyl alcohol and a citric acid gelatinizer, and magnetically stirring uniformly; regulating the pH value with aqua ammonia, stirring at room temperature to settle, and drying to obtain powder; and grinding the powder, screening, and sintering to obtain the milky lanthanum stannate nano powder. The method has the advantages of low reaction temperature, simple technique, low cost and high yield, and can implement industrial production. The method has better sintering process conditions for preparing the powder than the prior art. The prepared product has the advantages of small particles, high particle dispersion degree, favorable powder flowability and no obvious aggregation phenomenon.

Description

technical field [0001] The invention relates to the preparation of nanopowder, in particular to a pure-phase lanthanum stannate (La 2 sn 2 o 7 ) The preparation method of nanopowder. Background technique [0002] La 2 sn 2 o 7 Rare earth lanthanum stannate compound belonging to pyrochlore structure. It has excellent physical and chemical properties such as high-temperature thermal stability, chemical stability, and ion conductivity, and has good application prospects in ion / electronic conductors, lithium-ion batteries, and catalysis. It has been reported in the literature that the La synthesized by chemical co-precipitation method 2 o 3 doped SnO 2 A new phase La in electrode materials 2 sn 2 o 7 The emergence of (LSO) plays an important role in improving the electrical properties of electrodes. [0003] Lanthanum stannate (La 2 sn 2 o 7 ) The main processes are solid phase method, hydrothermal method and chemical co-precipitation method. However, the solid-...

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Problems solved by technology

However, the solid phase preparation of La 2 sn 2 o 7 For powder, the sintering temperature and sintering time are relatively strict, and the preparation cycle is very long

Studies by Chen et al. have shown that only when the sintering temperature is higher than 1520°C and the sintering time is about 34h, the single-phase La 2 sn 2 o 7 Powder can be synthesized; the preparation of La by hydrothermal method 2 sn 2 o 7 For powder, the sintering temperature is only about 180°C, the sintering time is 24h, and the synthesis yield is very low. To achieve large-scale synthesis, the requirements for high-pressure reactor equipment are relatively high, and the synthesis yield is difficult to be significantly improved; The chemical co-precipitation method has the advantages of high synthesis yield and short reaction cycle, but the disadvantage is that the purity is low and the sintering temperature is high, basically in the range of 1200-1400 °C, and the sintering time is about 10h

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