三维多孔碳海绵催化臭氧氧化有机染料

针对目前催化臭氧氧化催化剂效率较低、易损失等缺点，通过高温煅烧制备了三聚氰胺碳海绵，以廉价易得的三聚氰胺泡沫直接碳化制备出柔性碳海绵，探讨其在催化臭氧氧化降解印染废水反应中的应用潜力；采用SEM观察、比表面积测定、傅里叶红外光谱和X-射线光电子能谱对碳化前后泡沫进行了表征，探讨了碳化前后泡沫微观结构的变化与催化降解印染废水性能与机理。结果表明：氮气氛围下高温煅烧获得了兼具微孔/介孔结构的三维碳骨架，为催化反应提供充分暴露的活性位点和高效的传质通道；在催化臭氧氧化染料的过程中，973 K下制备的碳泡沫呈现出最为优异的催化活性，显著高于均相臭氧氧化和常规活性炭催化臭氧氧化；自由基捕获实验表明催化过程由羟基自由基(·OH)所主导，超氧自由基(·O₂^-)则发挥了次要作用；富含多孔结构的碳海绵对于活性自由基的生成起到了积极贡献，从而在实际印染废水处理中具有良好的降解性能。研究为开发低成本的三维碳材料用于催化臭氧降解有机污染废水提供了新思路。

Three-dimensional porous carbon sponge for catalytic ozonation of organic dyes

With interconnected network architecture, 3-D porous carbon is a promising material for energy conversion, catalysis and environmental applications. In view of the disadvantages of low efficiency and easy loss for the current catalytic ozonation catalyst, melamine carbon sponge, a type of the elastic carbon sponge, was prepared through high temperature calcination: the direct carbonization of inexpensive melamine foam. Then its potential application in catalytic ozonation of printing and dying wastewater was investigated. SEM, BET, FT-IR and XPS were used to characterize the foam before and after carbonization. Furthermore, the change in the foam microstructure before and after carbonization, and the performance and mechanisms of its catalytic degradation of printing and dyeing wastewater were discussed. The results showed that the high-temperature calcination of the foam under nitrogen atmosphere resulted in the formation of 3-D carbon skeleton with micro/mesoporous structures, which provided active sites and high effective mass transport channels for catalytic reactions. During catalytic ozonation of dyes, the catalyst from carbon sponge fabricated at 973 K presented the best activity, which was higher than homogeneous ozonation and conventional activated carbon catalyzed ozonation. Free radical capture experiments proved that·OH was the dominant reactive species for catalytic ozonation, while·O2- played a minor role. Due to the significant contribution of porous and conductive skeleton to the generation of reactive radicals, carbon sponge exhibited good performance for treating actual wastewater. This work provides a facile method to explore the low-cost 3-D catalyzed system for advanced oxidation of organic pollutants in wastewater.