镧掺杂TiO_2/g-C_3N_4复合光催化剂的制备及其可见光催化活性研究  

Preparation of lanthanum doping TiO_2/g-C_3N_4 composite photocatalyst for enhanced visible light photocatalytic activity

作　　者：傅敏[1,2] 徐海燕[1] 吴四维[1] FU Min XU Haiyan WU Siwei(College of Environment and Resources, Chongqing Technology and Business University, Chongqing 400067 Chongqing Key Laboratory of Catalysis and Environmental New Materials, Chongqing 400067)

机构地区：[1]重庆工商大学环境与资源学院,重庆400067 [2]催化与环境新材料重庆市重点实验室,重庆400067

出　　处：《环境科学学报》2017年第3期994-1002,共9页Acta Scientiae Circumstantiae

基　　金：重庆市应用开发计划重点项目(No.stc2013yykf B50008);重庆市教委科技项目(No.KJ120713)~~

摘　　要：以工业二氧化钛(TiO_2)、硝酸镧(LaN_3O_9·5H_2O)、三聚氰胺(C_3H_6N_6)为原料制备了La掺杂TiO_2/g-C_3N_4复合光催化剂.采用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、傅里叶变换红外(FT-IR)、紫外-可见吸收光谱(UV-Vis)、荧光光谱(PL)等表征方法对光催化剂结构进行分析,表明复合样品中La以La^(3+)形式存在于TiO_2晶体中,并形成TiO_2/g-C_3N_4异质结构,其禁带宽度减小、吸收带边红移,光催化效率有明显提高.以亚甲基蓝为目标污染物评价其光催化活性,镧掺杂量为4%(质量分数)、煅烧温度为520℃、煅烧时间为2 h时,复合样品光催化活性最佳,在12 LED灯下,180 min后对10 mg·L^(-1)亚甲基蓝溶液的去除率达97%.La doped TiO2/g-C3N4 composite photocatalyst was prepared using industrial titanium dioxide（ TiO2）,lanthanum nitrate（ LaN3O9·5H2O）and melamine（ C3H6N6） as raw materials. The structures of the samples were characterized by XRD,XPS,FT-IR,UV-Vis and PL techniques. The results showed that La existed in the form of La^3＋ions in the TiO2 crystal. The TiO2/g-C3N4 heterojunction structure was formed. For the La doped TiO2/gC3N4 heterojunction,the band gap decreased,the absorption band edge was red-shifted,and the photocatalytic efficiency was obviously improved. The photocatalytic activity of the samples was evaluated for the degradation of methylene blue solution under visible light irradiation. The results demonstrated that the photocatalytic activity of La doped TiO2/g-C3N4 composite photocatalyst could reach the highest efficiency when the amount of La dosage was 4%（ mass fraction）,the calcination temperature was controlled at 520 ℃ and the calcination time was maintained for 2 h. With the 12 LED lamp as the light source,the degradation ratio of MB reached 97% irradiation for 180 min.

关 键 词：La掺杂TiO2/g-C3N4复合物 异质结 亚甲基蓝 光催化 

分 类 号：X703[环境科学与工程—环境工程] X131