Synthesis of selenium-doped graphene nanoplatelets

Abstract

Selenium-doped graphene nanoplatelets (SeGnPs) were prepared by mechanochemical reaction between graphite and selenium (Se) powders. The high-velocity stainless steel balls in a planetary ball-mill reactor generate sufficient kinetic energy, which is delivered to graphite and Se powders and induces unzipping of graphitic C-C bonds and cracking of Se-Se bonds. Activated C and Se atoms have an opportunity to form covalent C=Se and C-Se-C bonds (as like C=O and C-O-C bonds) along the broken edges of SeGnPs. The resultant SeGnPs were characterized by various techniques including SEM, TEM, EDS, XPS, Raman, XRD, and TGA. Especially, AR-TEM images clearly showed that Se atoms with the dark atomic contrast are present only along the edge lines of SeGnPs. In contrast, the inner part (basal area) of the sheets shows a perfect graphitic structure, indicating that the mechanochemical unzipping of graphitic C-C bonds does not destroy the crystallinity of the basal plane.