Synthesis and use of bimetals and bimetal oxides in contaminants removal from water: a review

Water pollution aggravates water scarcity by contaminating large volumes of available water. There has been increasing interest in the use of bimetallic particles and bimetallic oxides for the removal of contaminants in water. This paper reviews the recent advances in the development of bimetals and bimetal oxides, and application in the treatment of environmental contaminants. 183 published studies (1999-2015) are reviewed in this paper. The synthesis methods of bimetals including chemical methods, physical methods, and biosynthesis methods and the synthesis of bimetal oxides including hydrothermal, impregnation, sol-gel, spray pyrolysis, and precipitation methods are summarized. Then the application of bimetals and bimetal oxides to remove different environmental contaminants in water including chlorinated organic compounds, heavy metal, arsenic and selenium, nitro compounds and azo dyes, anions and oxyanions are reviewed. The review focuses on experimental conditions, removal efficiency of contaminants, and reaction mechanism in the application of bimetals and bimetal oxides. Compared with monometals, bimetals have high catalytic or removal ability for contaminants. The synthesis and application of bimetals and bimetal oxides is remarked on.