The Preparation And Application Of Selenium Materials

Selenium (Se) has become the frontier and hot issue in chemistry, biology and medicine because it exhibits several useful properties such as excellent electrochemical performances and good biology activity. Especially, during the last few years, there has been growing interest in selenium nanoparticle owing to its special potential applications. In this paper, we prepared selenium nanoparticles, dextran/selenium nanoparticles, and selenium fertilizer. The paper is separated into four parts that are shown as follows:1. Tyrosine was selected as the reducing agent to deoxidize selenious acid and selenium nanoparticles with different morphologies was prepared under acidic environment by hydrothermal method. The results showed that the reaction become more complete with the increase of the time using appropriate amount of selenious acid, and reduction property was exhibited in amido group. Hydroxyl of hydroxybenzene was also oxidated using excessive amount of selenious acid. The morphology of nano-selenium was affected by reaction conditions, inclusive of reaction time, reaction temperature and pH value of solution. Se nanorod was obtained in the lower temperature, and there was a transformation of nanorod into sphere Se particle with the increase of reaction time or reaction temperature. In addition, rhombus-shaped nanoparticles were obtained under the lower pH value. Moreover, reactant concentration has played an important role in the crystallizability of the selenium nanoparticles. The transformation of amorphous Se (a-Se) into t-Se has happened in the higher reactant concentration. The mechanism of reaction about the reduction of selenious acid with tyrosine in acidic condition by hydrothermal method was discussed.2. Aspartic acid (Asp) was used as in situ template for the first time to synthesize t-Se particles by hydrothermal method, sonication-assisted and surfactant-assisted hydrothermal methods. The effects of hydrothermal reaction time, fore-sonication time of hydrothermal method, the type and concentration of surfactant and solvent,...