Porous MIn 2 S 4 (M = Zn, Cd) photocatalyst Preparation, Characterization and Photocatalytic Performance
|Keywords||Multiple sulfides Template Hydrothermal Ion doping Photocatalytic hydrogen evolution|
ZnIn2S4, CdIn2S4 and a series of n-MIn2S4 (M= Zn, Cd; n= Cr3+, Mn2+, Cu2+) porous photocatalysts have been successfully synthesized by hydrothermal method using different surfactants as soft templates. The effects of the preparation conditions on the structure and photocatalytic activity of MIn2S4 （M= Zn, Cd） photocatalysts were investigated in this paper. The conditions included the template, pH value, reacting solvent, hydrothermal temperature and hydrothermal time. The photocatalysts were characterized by X-ray diffraction, FESEM, EDS, UV-Vis diffuse reflectance spectrum, N2 absorption and X-ray photoelectron spectroscopy. The activity of photocatalytic hydrogen evolution under visible light was investigated.ZnIn2S4 photocatalysts prepared by hydrothermal method possessed hexagonal layered structure and slit-pore flower-sphere morphology. From the experiment results, it was found that the best ZnIn2S4 was obtained under these conditions, including CPBr as template, the CPBr amount as 0.21 g, pH value of reaction solution as 2.0, hydrothermal temperature as 140℃and hydrothermal time as 12 h. The ZnIn2S4 prepared under the optimized condition showed the highest activity and the average rate of hydrogen evolution reached 1544.8μmol/ （h·g）. The as-prepared CdIn2S4 porous photocatalysts was indexed as cubic phase. Using 0.57 g SDS as the template and water as solvent, the optimized CdIn2S4 product was obtained under 140℃for 12 h. The highest rate of hydrogen evolution over CdIn2S4 photocatalyst reached up to 527.5μmol/ （h·g）.n-MIn2S4 （M= Zn, Cd） photocatalysts doped with transition metal ions (Cr3+, Mn2+, Cu2+) performed better photocatalytic activity than MIn2S4. The doping ion greatly affected the crystal structure, surface morphology and optical property. The results showed that Mn2+ （0.5%）-ZnIn2S4 and Mn2+ （0.7%）-CdIn2S4 photocatalysts performed highest activity and the hydrogen evolution rates were 3286.4μmol/ （h·g） and 1296.2 μmol/ （h·g）, respectively.