纳米TiO2表面晶相结构转化及其光催化活性研究  

Transformation of surface crystalline phase structure of nano-TiO2 and accompanying photocatalytic activity

作　　者：卫毅梅 柏杨巍[1] 刘丹妮[1] 郭东衡 徐林辉 贾世琪 孙菲 WEI Yi-mei;BAI Yang-wei;LIU Dan-ni;GUO Dong-heng;XU Lin-hui;JIA Shi-qi;SUN Fei(Research Center for Comprehensive Control Water Pollution in River Basin,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Shanxi Research Institute of Environmental Science,Taiyuan 030027,China)

机构地区：[1]中国环境科学研究院流域水污染综合治理研究中心,北京100012 [2]山西省环境科学研究院,山西太原030027

出　　处：《现代化工》2019年第12期171-175,共5页Modern Chemical Industry

摘　　要：催化剂的表面结构对于调控其催化活性具有重要的作用。采用高温煅烧的方法诱导锐钛相纳米TiO2发生金红石相转变,对其光催化活性和金红石相含量分析发现,仅少量的金红石相生成可显著提高纳米TiO2光催化活性,同时明显改变催化体系中不同自由基的相对含量。·OH的生成浓度仅有稍微增加,而O2·-的浓度从0.233μM/h迅速增加到0.501μM/h,说明煅烧过程诱导纳米TiO2的表面结构发生显著改变,金红石相TiO2优先在纳米TiO2颗粒表面区域生成。通过与模型金红石相/锐钛相纳米TiO2表面异质结构对比,进一步验证了表面晶相异质结构可显著提高纳米TiO2催化活性。The surface structure of the catalyst plays an important role in adjusting and controlling its catalytic activity.Herein,the sintering treatment method is used to induce anatase nano-TiO2 to transform into rutile phase.The phase transformation is verified by XRD patterns.It is found from analyzing the photocatalytic activity and the content of rutile phase that even a small amount of rutile phase is formed,the photocatalytic activity of nano-TiO2 can be improved greatly and the relative content of different free radicals in the catalytic system will be obviously changed.The generation concentration of·OH enhances slightly but the generation concentration of O2-increases significantly from 0.233μM·h-1 to 0.501μM·h-1,which suggests an obvious structure change occurs on nano-TiO2 surface during sintering process,probably anatase-to-rutile phase transformation occurs preferentially in the surface area of nano-TiO2 particles.Compared with the model rutile/anatase nano-TiO2 surface heterostructure,it is further verified that the surface crystalline heterostructure can significantly improve the catalytic activity of nano-TiO2.To further demonstrate the formation of surface phase heterostructure,a model anatase/rutile TiO2 composite with surface heterostructure is fabricated for comparison,which verifies that the enhanced photocatalytic activity arises from the formation of surface anatase/rutile phase heterostructure.

关 键 词：光催化 纳米TIO2 晶相转变 表面晶相异质结构 

分 类 号：X131.2[环境科学与工程—环境科学]