摘要
采用高温固相法合成了铈掺杂的K2La2Ti3O10催化剂,利用X射线衍射(XRD)、紫外-可见漫反射(UV-visDRS)、透射电镜(TEM)和X射线光电子能谱(XPS)对催化剂进行了表征.考察了催化剂的可见光催化分解甲醇水溶液制氢的活性,并对可见光催化机理进行了分析.研究表明,铈的掺杂没有改变K2La2Ti3O10的微晶结构,并使催化剂粒径有所减小.紫外可见漫反射分析表明禁带宽度为2.3eV左右,对可见光具有较高吸收.XPS表明La和Ti为+3和+4价,而Ce则是+3和+4的混合价态.担载2wt%Pt后,在可见光下光催化活性大大提高,当铈的掺杂量为0.5mol%(即Ce取代La的摩尔百分量)时,光催化活性达到最大,产氢速率为0.05mmol/h;光照5h后产氢量为0.22mmol,而纯K2La2Ti3O10的产氢量只有0.037mmol.
Ce-doped K2La2Ti3O10 was prepared by a high temperature solid state reaction,and characterized by XRD,UV-Vis DRS,TEM and XPS.The photocatalytic activities of the Ce-doped K2La2Ti3O10 and pure K2La2Ti3O10 catalysts for hydrogen evolution were examined under visible light irradiation.The results showed that the Ce ion entered the crystal lattice of K2La2Ti3O10,and Ce doping resulted in the small size of particle.The Ce-doped K2La2Ti3O10 powder shifted the UV absorption band of K2La2Ti3O10 toward visible light region.According to the investigation of XPS,La and Ti exist mainly in the forms of ＋3 and ＋4 va-lences,respectively.The Ce 3d XPS basically denotes the mixture of Ce4＋/3＋ oxidation states giving rise to a myriad of peaks.The Ce-doped K2La2Ti3O10 shows a higher activity than K2La2Ti3O10 under visible light irradiation after they were loaded with 2 wt% Pt as co-catalysts.The highest activity was obtained with 0.05 mmol/h when K2La2Ti3O10 doped at 0.5 mol% of Ce ion to La;and after 5 h illumination,the amount of hydrogen production was got to 0.22 mmol,while that value of pure K2La2Ti3O10 was only 0.037 mmol.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2010年第3期211-216,共6页
Acta Chimica Sinica
基金
国家自然科学基金(No50972037)
唐山市重点实验室基金(No08360204A-3)
河北理工大学博士科研启动基金资助项目
