Method for preparing Nano Fe2O3

Abstract

This invention discloses a method for preparing uniform nanoscale Fe3O4. The method comprises: adjusting the pH value of ferrous salt solution to 9-11 with NaOH, adding trace amount of complexone, and oxidizing in air under the induction of visible light to obtain spherical Fe3O4 nanopowder. The particle sizes of the Fe3O4 nanopowder are 10-50 nm, and can be artificially controlled. The Fe3O4 nanopowder has such advantages as uniform particle size distribution, good dispersibility, high purity and high yield. The method is simple and economic.

Description

technical field [0001] The present invention relates to a kind of nano Fe 3 o 4 preparation method, especially a liquid phase preparation of ultra-fine uniform nano-Fe 3 o 4 Methods. Background technique [0002] Nano Fe 3 o 4 It has excellent performance in magnetism, catalysis, biology, etc. It not only shows new application value in traditional fields, but also becomes an important part of new materials such as magnetic liquid, magnetic microbeads, and magnetic drugs. Due to the size effect of nanoparticles, different sizes of Fe 3 o 4 Magnetic nanoparticles often exhibit different magnetic properties. But Fe 3 o 4 It is very easy to agglomerate during the generation process, which affects its application, so the preparation of nano-Fe with controllable monodisperse particle size 3 o 4 Powder has become the research focus of various countries. S.H.Sun et al. through thermal decomposition [Fe(acac) 3 ] In the presence of acetylacetone, oleylamine, etc., high-...

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Problems solved by technology

For example: D.K.Kim. used the co-precipitation method to obtain nano-Fe with a particle size of 13-60nm and different magnetic properties after surface treatment with sodium oleate 3 o 4 (J.Magnetism Magnetic Mater.2001, 225, 30-36); An Lijuan et al. used co-precipitation method, and used oleic acid and sodium dodecylbenzenesulfonate as double-layer surfactants to modify the surface, and prepared granules Stable water-dispersible nano-Fe with a diameter of 10 nm 3 o 4 (Acta Chemical Journal of Chinese Universities, 2005, 26 (2), 366-369); Wang Hanbin etc. also adopt co-precipitation method, add citrate to control nano-Fe 3 o 4 The growth of Fe, with a particle size of less than 5nm 3 o 4 particles, but the crystallization of the sample is not ideal (Journal of Inorganic Chemistry, 2004, 20(11), 1279-1283); but with Fe 2+ As a raw material, add alkali to control the pH value, and use air to oxidize the obtained Fe 3 o 4 The particle size is generally large, and there is no report of a particle size smaller than 20nm, and the uniformity is not good

In recent years, although in Fe 3 o 4 Significant progress has been made in nano-preparation and modification, but there are still two typical problems: (1) the raw materials for preparation are more expensive, the cost is higher, and the relative preparation process is more complicated; (2) for nano-Fe 3 o 4 Modification of the surface of the sample can reduce the grain size of the sample and improve the dispersion of the sample, but it will lead to nano-Fe 3 o 4 decline in magnetic properties