3维海绵状介孔氮化碳的制备及其光催化性能

Preparation of three-dimensional cavernous mesoporous carbon nitride and its photocatalytic activity

以二氧化硅(SiO_2)球体为模版、三聚氰胺(melamine)为前躯体,通过固相反应方法制备具有可见光催化活性的海绵状介孔石墨相氮化碳(mpg-C_3N_4).采用X射线衍射仪(XRD)、X射线光电子能谱分析仪(XPS)、冷场发射式扫描电镜(SEM)、透射电子显微镜(TEM)、比表面积测试仪(BET)、紫外可见分光光度计(UV-Vis)等对样品进行表征.以亚甲基蓝(MB)和甲基橙(MO)为目标降解物,以直接煅烧前躯体得到的块状氮化碳(bulk-C_3N_4)和多孔氮化碳(mpg-C_3N_4)为光催化剂,研究可见光辐射下两个样品的光催化特性.研究结果表明,多孔氮化碳(mpg-C_3N_4)对MB和MO的降解率优于块状氮化碳(bulk-C_3N_4)的,且优于传统的金属氧化物催化剂TiO_2的.经过120min光照后,mpg-C_3N_4样品对MB和MO的降解效率分别可达99.6%和99.9%,且在10^(-6)～10^(-7) mol·L^(-1)的浓度下依然有很高的降解效率,因此可对微量和痕量的有机污染物进行有效降解.

Mesoporous graphite carbon nitride (mpg-C 3N 4) with high visible light photocatalytic activity was prepared by the solid-phase reaction method using silica sphere and melamine. The microstructure and properties were characterized by XRD, XPS, SEM, TEM, BET, UV-Vis. Methylene blue (MB) and methyl orange (MO) were used as degradation targets. Bulk C 3N 4 and porous C 3N 4 materials obtained by direct calcination of precursors were used as photocatalysts. It was better than the traditional metal oxide catalyst TiO 2 under the photocatalytic properties. The results showed that the mpg-C 3N 4 degradation rate of MB and MO was much better than that of bulk-C 3N 4, and the degradation efficiency of MB and MO reached 99.6% and 99.9% after 120 min. The degradation efficiency of organic pollutants under trace and trace conditions was still high at a concentration of 10^-6 - 10^-7 mol·L^-1 . Therefore, it could effectively degrade trace and trace organic pollutants.