Zn掺杂TiO2纳米薄膜的制备和其光学性能研究.pdf

太原理工大学硕士研究生学位论文 Ti02结晶程度不高;随着热处理温度升高,Ti02的结晶性能提高。其中, 550。C处理后,Ti02薄膜材料的结晶度高,晶粒分布均匀,晶粒大小约为30 nm;而处理温度为650。C时Ti02由锐钛矿转变成了金红石相。不同温度处理后的Ti02纳米薄膜对紫外光的吸收能力有所不同。其中,经550。C处理后的材料对紫外光的吸收能力最强;650。C处理后的材料光吸收曲线有一定蓝移;且不同温度处理后的材料在可见光区都无明显吸收。经550。C热处理, 结晶性能及表面形貌都较好的锐钛矿相TiO:在紫外光照下催化降解MB溶液的能力很强。经300 min紫外光照,催化降解MB溶液效率达85%。而经650。C热处理的锐钛矿与金红石相混晶薄膜在紫外光照下催化降解MB 溶液的能力较弱,经300 min紫外光照,约降解75%。通过将不同比例ZnO粉末加入Ti02溶胶前驱体中的方法制备出 Ti02/ZnTi03复合光催化薄膜,在550。C下焙烧2 h后得到不同Ti02晶型和钙钛矿相ZnTi03的复合薄膜。Ti02/ZnTi03复合光催化薄膜中Ti02的晶型明显影响复合薄膜在紫外光下的光吸收性能,且复合结构中钛酸锌的含量对试样在紫外光区的吸光度随着钛酸锌含量的增加呈现先增强然后减弱的趋势。在Ti02/ZnTi03复合光催化薄膜结构中,当ZnTi03相含量较低时, 锐钛矿相TiO:、金红石相Ti02、钙钛矿相ZnTi03形成的三相复合薄膜在紫外光下的光催化活性优于纯Ti02,经300 min紫外光照后,降解MB溶液约为93%。以醋酸锌为zn2+源,:与钛酸锌复合的纳米薄膜材料。在550。C焙烧2 h后得到不同Ti02晶型和钙钛矿相ZnTi03的复合薄膜。以醋酸锌为Zn源进行掺杂后,薄膜表面形貌有明显不同:材料表万方数据太原理工大学硕士研究生学位论文面颗粒细小许多,且有一定团聚现象。当zn掺杂量较高后,在薄膜表面有 ZnO析出;但复合的结构并未对材料的光响应区域有所影响。锐钛矿相TiO: 与钙钛矿相ZnTi03的复合结构提高了光生载流子的分离效率。关键词:溶胶。凝胶法,Zn掺杂,ZnTi03/Ti02复合,光催化,光电性能万方数据太原理工大学硕士研究生学位论文 IV 万方数据太原理工大学硕士研究生学位论文 PREPARATl0N AND 0PTICAL PROPERTY STUDY OF ZINC DOPED Ti02 NANO FILM AB STRACT With thedevelopment oftechnology and advance insocialdevelopment, environmental and energy issues have e themost two important issues of human as a safe,non-toxic and easily obtained semiconductor material,has been widely used in solar energy and environment protection because ofits excellent performance inphotocatalysis and photoelectric effect. However,there are stilltwomaj orunresolved problems thatimpede thepractical application istitania’Sineffectiveness under visiblelight;the band gap of anatase is eV,which requires excitation wavelengths of L< thatlessthan5%of the solarfluxincident attheearth’Ssurface lies in this spectral regime,harvesting sunlight for photocatalytic or photo—electrochemical purposes would beenormously enhanced by extending thephoto-response ofYi02 other one isthegenerated conduction electron and valence band hole bination inthebulk decrea