Synthesis of selenium particles with various morphologies.

Uniform selenium spherical particles were prepared by reducing selenous acid with hydroquinone in the presence of Daxad 11G. The red colored colloidal dispersions displayed a distinct plasmon band at ~612 nm and were stable for extended time due to the negative surface potential of the particles. Structural analyses indicated that the Se spheres were aggregates of nanosize subunits crystallized in the hexagonal system. Selenium wires and rods were obtained by changing the pH and the composition of the precipitated dispersions and incubating them for extended time at moderate temperatures. The addition of a co-solvent played a major role in the re-crystallization of selenium spheres into anisotropic structures.