Morphological controlled synthesis and catalytic activities of gold nanocrystals

In this paper, we report a convenient and efficient procedure for controlling the morphologies of gold nanocrystals via varying the molecular structure of polyols. The gold nanostructures, from nanoplate to mixtures of rod, plate, and sphere, and nanosphere, can be synthesized quantitatively with 1,3-propylene glycol, 1,2-propylene glycol, and glycerol, respectively. On the basis of the results, we speculate that polyols with diverse position and number of OH group play an important role in determining the geometric structures and morphologies of the final products. It may be due to the specific interaction between OH groups and Au3+ ions, which affect selective growth of various planes of gold nanocrystals. In addition, the catalytic activity of the obtained different shaped gold nanocrystals for hydrogen production from formaldehyde solution at room temperature has also been investigated. The gold nanoplates exhibit higher catalytic activities than spherical gold nanoparticles and the mixtures of rod, plate, and sphere.