作 者：
邢伟男;程珂;熊若帆;薛樱涔;韩建刚;吴光瑜
单 位：
南京林业大学南方现代林业协同创新中心;南京林业大学生物与环境学院;江苏洪泽湖湿地生态系统国家定位观测研究站
关键词：
生物炭;氮化碳;光催化;染料降解;稳定性
摘 要：
针对类石墨相氮化碳(g-C_3N_4)在光催化降解污染物过程中光生载流子复合严重,导致其光催化活性差的问题,研究中以稻壳为生物炭原料、三聚氰胺为g-C_3N_4原料,采用热缩聚法构筑了生物炭修饰的g-C_3N_4复合光催化剂。生物炭材料的引入,可以充当良好的光生电子转移通道,促进复合材料中光生载流子的分离与传输,进而提高光催化降解罗丹明B(RhB)的效率。利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、紫外可见漫反射仪(UV-Vis-DRS)等,对所制备的复合材料的晶体结构、官能团组成及光学性质进行表征。通过在可见光下降解RhB,评价所制备材料的光催化性能。结果表明,所构筑的生物炭修饰g-C_3N_4复合光催化剂表现出优越的光催化降解RhB活性。探究了不同负载量生物炭对复合光催化剂降解RhB的影响,其中3%的生物炭添加量复合光催化剂具有最优的光催化性能,80 min内就可以将RhB完全降解。此外,通过对复合光催化剂的循环性能测试表明所制备的材料具有良好的循环稳定性。该项研究工作不仅拓宽了生物炭材料的应用范围,同时也为高性能、高稳定的光催化材料的构筑提供了良好的思路,对实现农林废弃物的资源化利用具有重大意义和广泛的应用价值。
译 名：
Study on biochar functionalized g-C_3N_4 photocatalyst towards improved photocatalytic degradation performance
作 者：
XING Weinan;CHENG Ke;XIONG Ruofan;XUE Yingcen;HAN Jiangang;WU Guangyu;College of Biology and the Environment,Nanjing Forestry Univiersity;Co-Innovation Center for the Sustainable Forestry in Southern China,Nanjing Forestry Univiersity;National Positioning Observation Station of Hungtse Lake Wetland Ecosystem;
关键词：
biochar;;g-C_3N_4;;photocatalytic;;dyes degradation;;stability
摘 要：
As a metal-free polymeric semiconductor material, graphitic carbon nitride(g-C_3N_4) has been emerged as a particularly promising photocatalyst due to its advantages of high stability, low cost, controllable structure and performance. However, the bulk g-C_3N_4 often suffers from the small surface area, insufficient optical absorption, and fast recombination of photoexcited electron and hole, which greatly limits the photocatalytic activity. To date, a good deal of strategies has been applied to improve the photocatalytic activity; for example, the morphology control(nanosheets, hollow microspheres, nanotubes and nanoribbons); element doping(nonmetal element doping or metal element doping); semiconductor composite or compositing with other carbon materials. In view of the fast recombination of the photogenerated charge carrier of g-C_3N_4 during the photocatalytic reaction, coupling with the carbonaceous materials is a good method for the enhancement of photocatalytic performances of bulk g-C_3N_4. Herein, a novel biochar modified g-C_3N_4 composite photocatalysts was constructed by high temperature polycondensation using rice husk and melamine as the precursors. The introduction of biochar could act as effective electron transfer channels to facilitate charge carrier separation in BC CN composites, thus greatly improving the photocatalytic degradation ability. The X-ray diffraction XRD, Fourier transform infrared spectroscopy(FT-IR) and ultraviolet visible diffuse reflectance spectroscopy(UV-Vis-DRS) were used to characterize the crystal structure, composition and optical properties of the as-prepared photocatalysts. XRD and FT-IR results indicated that the original crystal structure and chemical construction of g-C_3N_4 was well-maintained after the incorporation of biochar. The UV-vis DRS analysis results showed that the biochar modified g-C_3N_4 composite photocatalysts improved light absorption. The elemental analysis measurements suggested that the biochar has been introduced into the composite photocatalyst and caused the increasing of carbon element content. At last, the photocatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of RhB under the visible light. The as-prepared biochar modified g-C_3N_4 photocatalysts showed excellent visible-light photocatalytic degradation activity for RhB. Particularly, the 3% biochar modified photocatalyst had the best photocatalytic performance, and the RhB could be completely degraded within 80 min. Meanwhile, the BC CN3 exhibited high stability and reusability.
