• 关键词：La掺杂TiO₂/g-C₃N₄复合物  异质结  亚甲基蓝  光催化

• 基金项目：重庆市应用开发计划重点项目（No.stc2013yykfB50008）；重庆市教委科技项目（No.KJ120713）

• 傅敏
• 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

• 徐海燕
• 重庆工商大学环境与资源学院, 重庆 400067

• 吴四维
• 重庆工商大学环境与资源学院, 重庆 400067

• 摘要：以工业二氧化钛（TiO₂）、硝酸镧（LaN₃O₉·5H₂O）、三聚氰胺（C₃H₆N₆）为原料制备了La掺杂TiO₂/g-C₃N₄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La³⁺形式存在于TiO₂晶体中，并形成TiO₂/g-C₃N₄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%.

• Abstract：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 La³⁺ ions in the TiO₂ crystal. The TiO₂/g-C₃N₄ heterojunction structure was formed. For the La doped TiO₂/g-C₃N₄ 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.

• Key words：La doped TiO₂/g-C₃N₄ composite  heterojunction  methylene  photocatalysis

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