Chinese Academy of Sciences

Changchun Institute of Applied Chemistry

Changchun Institute of Applied Chemistry Chines Academy of Sciences

Qiang Wang

Lijia An

Daocheng Pan

Xiangling Ji

Shichun Jiang

Nana Zhao

The present invention belongs to a method for preparing organic ligand-capped titanium dioxide nanocrystals, wherein the method comprises steps of using methyl titanate, ethyl titanate, n-propyl titanate, iso-propyl titanate, butyl titanate or titanium tetrachloride as a titanium source, and with capping by oleic acid or an organic capping agent, reacting the titanium source in an organic non-polar solvent with an aqueous alkaline substance solution in the interface at a temperature of 25 to 280&#xb0; C. for 0.5 to 240 hrs, thus a transparent sol containing titanium dioxide nanocrystals is obtained, said the titanium dioxide nanocrystals have particle diameters of 1-20 nm. The preparing process has the features of mild reaction conditions and is a simpler and easier method with a shorter preparation period, thereby facilitating the industrialization.

Method for preparing organic ligand-capped titanium dioxide nanocrystals

A two-phase thermal method for the preparation of cadmium sulfide quantum dots where a cadmium source, a sulfur source and a capping agent are heated in water and water-insoluble organic solvents forming a two-phase system. By means of varying reaction time, cadmium sulfide quantum dots of different sizes can be prepared. Quantum dots already obtained can be used as crystal seeds in the reaction of newly added reaction precursor to give larger sized quantum dots with a size distribution similar to that of the initial crystal seeds so as to realize the control of quantum dot size. The quantum dots obtained in the present invention have relatively narrow size distribution, and emit royal purple or blue light under ultraviolet lamp, with a photoluminescence quantum efficiency of from 3 to 60%.

Two-phase thermal method for preparation of cadmium sulfide quantum dots

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Changchun, China

Qiang Wang