Direct preparation of semiconductor iron sulfide nanocrystals from natural pyrite

Abstract

Stable and monodisperse colloidal iron sulfide nanocrystal (FSNC) (<100 nm) inks were prepared directly from natural pyrite dust without any chemical conversion. After selective modification by octadecylxanthate, sedimentation behaviors of FSNCs were reversibly regulated in different mixed organic solvents. In this way, FSNCs were efficiently separated out of pyrite dust, and stable FSNC inks were then prepared. The inks were applied in drop coating semiconductor FSNC films, of which the structure and semiconductor properties were comparable with the film prepared by classical vulcanization. The FSNCs film could be further regulated simply by heating in N2 and S vapors and exhibited obvious photoconductive properties. Different from traditional synthesis processes, no chemical conversions occurred during the process from the natural pyrite to the FSNCs. Therefore, reagents and energy consumption could be largely reduced. It provides a simple yet greener way for preparing nano-sulfide semiconductors from widely existing natural sulfide ores.