【摘要】 利用酸催化的Sol-gel法制备纯的和不同掺杂量的Zn2+掺杂TiO2纳米粉体,并用XRD、BET、XPS、SPS等技术对样品进行表征.考察Zn2+掺杂量和焙烧温度对样品的光催化降解亚甲基蓝活性、相结构、晶粒尺寸和表面织构特性的影响,并结合表面光电性质和表面组成等探讨Zn2+掺杂对纳米TiO2光催化活性的影响机制.结果表明:适量掺杂Zn2+可以提高纳米TiO2的光催化活性;当Zn2+掺杂量为0.75%,焙烧温度为500℃时,制备的Zn2+掺杂TiO2纳米粉体的光催化活性最佳.Zn2+掺杂TiO2纳米粉体的光催化活性的提高应归功于Zn2+掺杂促进了光生电子和空穴的分离,抑制相变和晶粒长大从而增强光生e-/h+的氧化还原能力,增加表面羟基,改善样品表面的吸光性能.更多还原

【Abstract】 Pure TiO2 and TiO2 doped with different amounts of Zn2+ nanoparticles were prepared by the acid-catalyzed sol-gel method using Ti(OC4H9)4and Zn(NO3)2 as raw materials and characterized by the techniques such as XRD,BET,XPS and SPS.The effects of the amount of Zn2+-doping and calcination temperature on the photocatalytic activity for photocatalytic degradation of methylene blue in aqueous solution,phase structure,crystallite size and surface texture of the nanopowders were investigated,by which the mechanism of effects of Zn2+-doping on the photocatalytic activity of TiO2 nanoparticles was also discussed in combination with the surface photoelectric properties and surface composition of the nanoparticles.The results show that proper amount Zn2+-doping can effectively enhance the photocatalytic activity of TiO2 nanopowders.0.75% Zn2+-doped TiO2 nanopowders calcined at 500 ℃ for 2 h show the highest photocatalytic activity.Compared with pure TiO2,the enhanced photocatalytic activity of Zn2+-doped TiO2 nanopowders is due to the increase of separation efficiency of photo-generated electron-hole pairs,the enhancement of redox power of photo-generated e-/h+resulted from the inhibition of the phase transformation from anatase to rutile and crystal grain growth,the increase of density of surface hydroxyl groups,and the improvement of the light absorption properties of the particle surface.更多还原