掺Br氮化碳-纤维素复合材料的制备及其对亚甲基蓝的光催化降解性能

Photodegradation of methylene blue over Br-doped carbon nitride/cellulose composite

为了提高石墨相氮化碳(g-C_3N_4)的光催化活性并实现其回收再利用,首先制备掺Br氮化碳,再将其与纤维素复合,制备具有宏观三维多孔结构的掺Br氮化碳-纤维素复合材料,研究其对亚甲基蓝(MB)的光催化活性。研究结果表明:制备得到的掺Br氮化碳-纤维素复合材料具有良好的三维多孔结构,掺Br氮化碳很好地负载于复合材料表面及孔壁;掺Br氮化碳-纤维素复合材料具还展现出较好的力学性能,当压缩应变为80%时,压缩应力达到207kPa。掺Br氮化碳-纤维素复合材料能够在160min光照时间内降解98%的亚甲基蓝,优于掺Br氮化碳;在H_2O_2辅助下,其降解效率在120min能达到99.5%。宏观三维的掺Br氮化碳-纤维素复合材料极易回收再利用,经4次循环,其对亚甲基蓝的光催化效率仍高于85%。研究结果对于实现宏观三维掺Br氮化碳-纤维素复合材料对规模化水污染治理具有一定的参考意义。

In order to improve the photocatalytic activity and cycle performance of graphite phase carbon nitride （g-C3N4）, the Br doped carbon nitride and macroscopic three dimensional Br doped carbon nitride cellulose composite was prepared, and its photocatalytic activity of methylene blue （MB） was studied. The results showed that the obtained Br doped carbon nitride cellulose composite exhibited three dimiensional porous structure. The Br doped carbon nitride was well supported on the surface of the composite. Meanwhile, the Br doped carbon nitride cellulose composite possessed good mechanical property, the compressive stress reached 207 kPa when the compressive strain was 80%. Br doped carbon nitride cellulose composite exhibited better photocatalytic activity than Br doped carbon nitride and could remove 98% of MB after irradiation for 160 rain; with the mediation of H2O2, the photodegradation efficiency of Br doped carbon nitride cellulose composite reached 99.5% after 120 rain light irradiation. As a macroscopic 3D photocatalyst, Br doped carbon nitride cellulose composite can been easily reused, and the photodegradation rate of MB by Br doped carbon nitride cellulose composite can still higher than 85 after four cycles. This article has a certain guiding significance for the application of the macroscopic three dimensional Br doped carbon nitride cellulose composite in large scale water pollution treatment.