Preparation of Layered K 4 Nb 6 O 17 and its Photocatalytic Activity for Hydrogen Production

The K4Nb6O17 powders were synthesized via a high temperature solid phase reaction and the effects of calcination temperature and calcination time were investigated. The powers were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet-visible diffuse reflection spectra (UV-VIS). The photocatalytic properties of these catalysts for hydrogen production were also investigated in the presence of Na2S and Na2SO3 sacrificial reagents. The results revealed that the optimal synthesis condition is calcination for 2h under 1000°C. Grain-like particles could be obtained with a rapid temperature rising rate, while rod-like particles were obtained with a slow rate. The K4Nb6O17 sample exhibited high activities for photocatalytic hydrogen production under UV light, and the highest activity of 95.4 mmol/(g cat) was achieved over the sample which at 1000°C for 2h with the temperature rising rate of 20°C/min.