Preparation and Photocatalytic Hydrogen Generation Activity of Nitrogen Doped SrTiO_3 under Visible Light Irradiation

SrTiO_3 photocatalysts were prepared by a sol-gel method,and nitrogen-doped SrTiO_3 were further prepared by a solid phase method.Nitrogen-doped SrTiO_3 loaded with Pt were prepared by photodeposition method and hydrogen reduction method.These photocatalysts were characterized by XRD,SEM,UV-Vis diffuse reflectance spectra,fluorescence spectrum and the photocatalytic hydrogen generation activities were investigated under visible light irradiation.The effects of different nitrogen sources,doped content,calcination temperature and the content of loaded Pt on the hydrogen gener- ation activity of catalysts were investigated.The results indicate that three nitrogen source reagents demonstrate different doping effect,i.e.hexamethylenetetramine(HMT)EDTAurea and the doping effect of EDTA is slightly lower than HMT.On the condition that the nitrogen source is HMT,the mass proportion of SrTiO_3 and HMT is 1:3,and the calcination temperature is 450℃,the optimized photo- catalytic hydrogen generation activity of photocatalysts can be achieved.The photocatalytic hydrogen generation activity is greatly improved by loading metal Pt.The photocatalytic activity of photocata- lysts prepared by hydrogen reduction method is better than that prepared by photodeposition method. On the condition that the optimized loaded content is 2wt%,the hydrogen generation amounts of these two photocatalysts are up to 6.89mmol and 2.24mmol within 6h respectively,which are 12 times and 4 times more than that of the unloaded Pt samples.