摘要
以四氯化钛为钛源,硫脲为硫源,采用液相水解-沉淀法制备了S掺杂的TiO2/SiO2(S-TiO2/SiO2)催化剂,并以苯酚为模型物,考察了催化剂在可见光区、紫外光区和太阳光下的光催化活性,以及催化剂的使用寿命和分离性能.采用X射线光电子能谱、傅里叶变换红外光谱、紫外-可见漫反射光谱、X射线衍射、透射电镜及N2吸附-脱附等技术对催化剂进行了表征.结果表明,S以+6价形式进入TiO2体相并置换晶格中的Ti4+,适量S掺杂的S-TiO2/SiO2在紫外光区、可见光区和太阳光下均表现出较高的光催化活性.SiO2与TiO2界面间有Ti-O-Si键形成,结合牢固.S掺杂在TiO2表面生成Ti-O-S键,形成新的能级结构,使光催化剂在450～550nm产生吸收,诱发TiO2可见光催化活性;同时提高了TiO2表面羟基数量.SiO2的加入可减小TiO2颗粒的平均尺寸,增大催化剂的比表面积,改善催化剂的分离性能,提高催化剂的使用寿命.
S-doped visible-light response S-TiO2/SiO2 photocatalyst samples were prepared by a hydrolysis-precipitation method.The photocatalytic activity was investigated by the degradation of phenol.The separability of S-TiO2/SiO2 was determined by sedimentation.X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,UV-Vis diffuse reflectance spectroscopy,X-ray diffraction,transmission electron microscopy,and N2 adsorption-desorption were used for catalyst characterization.The results showed that cationic S6＋ was incorporated into TiO2 lattice and substituted part of Ti4＋.S-TiO2/SiO2 with suitable S-doping exhibited higher activity under ultraviolet light,visible light,and solar irradiation.S-TiO2/SiO2 exhibited better decanting ability and less deactivation.Doped-S can form a new bond of Ti-O-S above the valence band of TiO2 to extend the adsorption edge to 450-550 nm,and can increase amount of surface OH-of TiO2.The addition of SiO2 can form a new bond of Ti-O-Si,beneficial to the high dispersion,and larger surface area of S-TiO2/SiO2.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第6期993-999,共7页
基金
国家自然科学基金(31000269)
福建省高等学校杰出青年科研人才培育计划(JA11072)~~
