Formation of Ge−S Bonds from AOT-Coated GeO2 Nanoparticles at High Temperature: An in Situ Heating EXAFS Investigation

Cubic germanium dioxide (GeO 2 ) nanoparticles coated by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) were synthesized with a reverse micelle technique. In situ heating extended X-ray absorption fine-structure technique was used to investigate the change of the local atomic structure and electronic structure around germanium. A direct formation of Ge−S bond was found from GeO 2 at high temperature and ambient pressure. This Ge−S bond was identified to be temperature-dependent. The change of the local structure with heating is discussed. This study provides a routine process to synthesize GeS 2 from GeO 2 at higher temperature and ambient pressure.