Sulfurization synthesis and photocatalytic activity of oxysulfide La3NbS2O5

The oxysulfide La3NbS2O5 was synthesized by sulfurization using H2S and characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (DRS) and field emission scanning electron microscopy (FE-SEM). The relationship between the sulfurization conditions and the photocatalytic activities for H2 evolution was investigated. Sulfurization method allowed for synthesis of La3NbS2O5 at much lower temperatures and significantly shortened reaction time of 1 h compared with conventional solid-state techniques. The particle morphologies were regular platelike with sizes of 0.1-0.6 μm and smooth surfaces. The highest activity for H2 evolution was obtained at 1073 K for 1 h, which was about 1.83 times that of La3NbS2O5 prepared by solid-state method.