硫氰酸铵辅助双氰胺制备g-C_(3)N_(4)及其光催化性能研究  

Preparation of g-C_(3)N_(4) with Dicyandiamide Assisted by Ammonium Thiocyanate and Its Photocatalytic Performance

作　　者：任学昌[1] 时秋红 张玉杰 杨林海 张曦 REN Xuechang;SHI Qiuhong;ZHANG Yujie;YANG Linhai;ZHANG Xi(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学环境与市政工程学院,甘肃兰州730070

出　　处：《中国材料进展》2023年第6期514-520,共7页Materials China

摘　　要：以双氰胺和硫氰酸铵为前驱体,将它们按照不同的质量比混合,600℃高温煅烧制备g-C_(3)N_(4)同型异质结复合材料光催化剂。采用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、傅立叶红外光谱仪(FTIR)、紫外-可见漫反射吸收光谱仪(UV-vis DRS)等对制备的材料进行了表征分析。以罗丹明B为模拟污染物,考察了制备的g-C_(3)N_(4)在可见光(λ>420 nm)下的催化活性及循环利用稳定性。通过活性物种捕捉实验探寻其降解机理,结果表明,双氰胺与硫氰酸铵按3∶2混合制备的g-C_(3)N_(4)的光催化降解罗丹明B的效率2 h达到了92.53%,是纯双氰胺制备的g-C_(3)N_(4)的1.35倍,是纯硫氰酸铵制备的g-C_(3)N_(4)的1.75倍。以双氰胺和硫氰酸铵为前驱体制备的g-C_(3)N_(4)是同型异质结,提高了光生载流子的分离效率,活性物种捕捉实验表明对催化活性起主要作用的是超氧自由基(·O_(2)^(-))。Graphite phase carbon nitride heterojunction composites were prepared by calcination at 600℃ with dicyandiamide and ammonium thiocyanate as precursor.The materials were characterized by X-ray diffractometer(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM),Fourier transform infrared spectroscopy(FTIR)and UV-visible diffuse reflectance absorption spectrum(UV-vis DRS).The catalytic activity of g-C_(3)N_(4) under visible light(λ>420 nm)and the recycling stability were investigated using rhodamine B(RhB)as a simulated pollutant.The degradation mechanism was explored by the active species capture experiment.The results showed that the photocatalytic degradation efficiency of g-C_(3)N_(4) prepared by the mixture of dicyandiamide and ammonium thiocyanate at a ratio of 3∶2 reached 92.53%in 2 h,which was 1.35 times that of g-C_(3)N_(4) prepared by pure dicyandiamide and 1.75 times that of g-C_(3)N_(4) prepared by pure ammonium thiocyanate.The g-C_(3)N_(4) prepared by dicyandiamide and ammonium thiocyanate as precursor is a homotype heterojunction,which improves the separation efficiency of photogenerated carriers.The active species capture experiment showed that the superoxide radical(·O_(2)^(-))plays a major role in catalytic activity.

关 键 词：光催化 双氰胺 硫氰酸铵 异质结 罗丹明B 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学]