New evidence of a thermodynamically stable nanophase: CdS in 4 M KOH–tert-butanol solution

Abstract

Thermodynamically stable nanophases have been confirmed as an important technical means of nano-synthesis. In this work, CdS nanosheets with a thickness of 10 nm were confirmed as a new thermodynamically stable phase under hydrothermal conditions in a 4 M KOH–tert-butanol solution at 180 °C. The thermodynamically stable phase of CdS varied with the KOH concentration in the system, but the morphology of the nanosheets was independent of the size of the CdS precursor (3 nm, 9 nm, or bulk). The thermodynamically stable nanosheets were consistent with the negative effective interfacial free energy of the CdS (001) face of the wurtzite structure. Further research showed the microprocess of transformation into nanosheets from bulk CdS. The new thermodynamically stable nanostructures open up possibilities for industrial mass production of nanomaterials and green synthesis.