摘要
通过硬模板法,采用氰胺前驱物和二氧化硅纳米管(SiO2-NTs)模板,合成石墨相氮化碳纳米管(CN-NTs)光催化剂。采用扫描电镜(SEM)、透射电镜(TEM)、X射线粉末衍射(XRD)、傅立叶变换红外光谱(FT-IR)、氮气吸附/脱附测试、紫外可见漫反射光谱(UV-Vis DRS)、荧光光谱、热重分析(TGA)等手段对CN-NTs催化剂的结构与性能进行表征。结果表明,CN-NTs的化学组成是石墨相氮化碳(g-C3N4),形貌为均匀的纳米管,且是介孔材料。与体相氮化碳(B-CN)和介孔石墨相氮化碳(mpg-CN)相比,CN-NTs的光吸收带边蓝移到440nm,荧光发射谱的峰强减弱。在可见光(λ﹥420nm)照射下,CN-NTs具有较高的光催化分解水活性,产氢速率为58μmol/h,且表现出良好的光催化活性稳定性和化学结构稳定性。研究结果表明纳米管状结构能有效促进g-C3N4半导体激子解离,提高光生电子-空穴的分离效率,进而显著优化g-C3N4的光催化产氢性能。
Graphitic carbon nitride nanotubes(CN-NTs)photocatalyst has been synthesized by a hard-template method by using cyanamide as a precursor and silica nanotubes(SiO2-NTs)as a hard template.The structure and properties of CN-NTs catalyst are characterized by the techniques of scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray powder diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),nitrogen absorption/desorption experiment,ultraviolet visible diffuse reflectance spectroscopy(UV-Vis DRS),fluorescence spectra and thermogravimetric analysis(TGA).As demonstrated by the experimental results,CN-NTs possess the chemical structure of graphitic carbon nitride(g-C3N4)and the morphology of uniform nanotubes,and belong to mesoporous materials.Compared with the bulk carbon nitride(B-CN)and the mesoporous graphitic carbon nitride(mpg-CN),the optical absorption band edge of CN-NTs blue-shifts to 440 nm,and the peak intensity of the fluorescence emission spectra for CN-NTs reduces.With the visible light irradiation(λ420nm),CN-NTs show an outstanding photocatalytic water splitting activity with the hydrogen evolution rate of 58μmol/h,and also demonstrate excellent stability in photocatalytic activity and chemical structure.The investigation results indicate that the nanotube structure effectively promotes the exciton separation of g-C3N4 semiconductor,and improves the separation efficiency of photogenerated electrons and holes,thus remarkably optimizing the photocatalytic activity of g-C3N4 toward hydrogen evolution.
出处
《影像科学与光化学》
CAS
CSCD
北大核心
2015年第5期417-425,共9页
Imaging Science and Photochemistry
基金
国家重点基础研究发展规划973项目(2013CB632405)
国家自然科学基金资助项目(21425309和21173043)
高等学校博士学科点专项科研基金(20133514110003)资助
关键词
石墨相氮化碳
纳米管
硬模板
光催化
氢能
graphitic carbon nitride
nanotube
hard template
photocatalysis
hydrogen energy