XPS and Raman study of the active-sites on molybdenum disulfide nanopetals for photocatalytic removal of rhodamine B and doxycycline hydrochlride

Abstract

Molybdenum disulfide (MoS₂) nanopetals were successfully synthesized by hydrothermal method (sample without sintering) and then sintered at different temperature (sintered samples). The products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen (N₂) adsorption analyses for Brunauer–Emmett–Teller (BET) specific surface area measurements, X-ray photoelectron spectrum (XPS) and Raman spectrum. XRD pattern indicated that the samples can be indexed to hexagonal phase 2H-MoS₂. SEM and TEM images showed that the sintered MoS₂ nanopetals had sizes ranging from 150 to 300 nm with almost the same morphology. The pore structure and surface area were nearly the same for the three sintered MoS₂ nanopetals. Interestingly, XPS and Raman spectra implied that there was a few 1T-phase in the MoS₂ nanopetals which enhanced the photocatalytic performance greatly when sintered at low temperature.