以SiO_2为模板制备高比表面积g-C_3N_4光催化剂

Prepartion of high surface area g-C_3N_4 photocatalyst with SiO_2 as a template

比表面积大小是限制普通块状g-C_3N_4(Bulk-C_3N_4)光催化性能的重要因素,以三聚氰胺为原料,SiO_2纳米粒子为嵌入剂,采用一种简便的方法制备出一种具有纳米片结构的高比表面积g-C_3N_4(HA-C_3N_4).同时使用X射线粉末衍射(XRD)、傅里叶变化红外光谱(FT-IR)、氮气吸脱附(BET)、透射电镜(TEM)、紫外可见光谱(UV-vis)和荧光光谱(PL)等表征手段分析了所制备材料的结构、形貌特征、比表面积和光学性质.结果表明:所制备的HA-C_3N_4具备纳米薄片结构,其比表面积相比于Bulk-C_3N_4由原来的7.1 m^2/g提升到了97.3 m2/g.以罗丹明B(Rh B)的降解评价了HA-C_3N_4的光催化性能,结果表明:当m(SiO_2)∶m(三聚氰胺)=3∶7时,HA-C_3N-4具有最好的光催化活性,反应速率常数k达到0.055 9 min^(-1),是Bulk-C_3N_4的6倍.

The specific surface area had been an important factor in limiting the photocatalytic property of bulk graphitic carbon nitride （Bulk-C3N4 ）. A facile method was adopted to prepare high specific surface area gra- phitic carbon nitride （HA-C3N4 ） ultrathin nanosheet with melamine as precursors and SiO2 nanoparticles as intercalators. Meanwhile, X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR）, Brunauer-Emmett-Teller measurements （ BET ）, transmission electron microscopy （ TEM ）, uhraviolet-visble spectroscopy （ UV-vis ） and photoluminescence spectrum （ PL ） were used to analyze the structures, morphologies, surface area and optical properties of the prepared HA-C3N4. The results indicated that the prepared HA-C3 N4 possessed nanosheet structure. Compared with Bulk-C3 N4, the specific surface area of HA-C3 N4 increased from 7.1 m^2/g to 97.3 m^2/g. The activity of the HA-C3N4 was tested via the photocatalytic degradation of rhodamine B. The HA-C3N4 which m（ SiO2 ）：m（melamine） =3：7 showed the best photocatalytic activity. The degradation rate of HA-C3N4 （0.055 9 min^-1） was 6 times higher than that of Bulk C3N4.