Growth of ZnS microfans and nanosheets: Controllable morphology and phase

Zinc sulfide with different phases and morphologies were solvothermally synthesized in diethylenetriamine (DETA) or a mixed solution of DETA and water at 180 °C. Wurtzite ZnS microfans composed of nanobelts with thickness of 30 nm were formed in pure DETA. Sphalerite ZnS nanosheets with thickness of 20 nm were produced in a mixed solvents of DETA and water with a volume ratio of 3:1. As the volume ratio of DETA to water was more than 3:1, the products were also nanosheets, while these nanosheets were in the mixed phases of wurtzite and sphalerite. UV–vis absorption spectrum of the wurtzite ZnS microfans showed a strong blue shift of 27 nm relative to the band gap of bulk wurtzite ZnS, which was attributed to the quantum size effect. Photoluminescence (PL) spectrum of wurtzite ZnS microfans presented a strong emission at 432 nm and a weak emission at 412 nm, which are in accordance with the reported data. The sphalerite ZnS nanosheets had a PL peak at 424 nm, indicating a weak deep-trap emission feature.