氮掺杂还原氧化石墨烯泡沫吸附/活化过硫酸盐协同去除双酚A的研究

Removal of bisphenol A by nitrogen-doped reduced graphene oxide foam via adsorption/peroxydisulfate activation

利用氧化石墨烯和氨水为原料,采用水热法-冷冻干燥技术制备了易回收氮掺杂还原氧化石墨烯泡沫(N-RGF)催化剂,通过SEM,XRD,XPS,FT-IR,BET和TG等手段对催化剂结构和表面物理化学性质进行表征和分析.利用N-RGF通过吸附/活化过二硫酸盐(PDS)降解协同去除双酚A(BPA),优化了其制备条件,并探讨去除机理.结果表明,N-RGF为网状三维结构,孔径约为1~5μm,最优条件为180℃水热反应20h,氮掺杂量为6%.制备的N-RGF降解BPA速率是RGF的4.88倍.活性物种捕获实验和电子顺磁共振(EPR)研究结果显示单线态氧(^(1)O_(2))是N-RGF活化PDS降解BPA的主要活性物种.HPLC-MS检测了降解过程的中间体,并提出了可能的降解途径.MCF-7雌激素活性测试结果显示N-RGF通过吸附/活化PDS可有效消除母体的雌激素活性而不产生雌激素活性更强的中间体.

The nitrogen doped reduced graphene oxide foam(N-RGF)was prepared by hydrothermal method followed freeze-drying treatment using graphene oxide and ammonia as starting materials.The structure and surface physical-chemical properties of as-prepared catalysts were investigated and analysed by SEM,XRD,XPS,FT-IR,BET and TG techniques.The N-RGF was used to activate peroxydisulfate(PDS)for BPA removal via adsorption/degradation synergistically.The results showed that the N-RGF catalyst was a three-dimensional structure with average pore size(1~5μm).Its optimal preparation conditions were 6%nitrogen doping amount and hydrothermal treatment at 180℃for 20h.The degradation rate constant of BPA over N-RGF activated PDS was 4.88 times than that over RGF activated PDS.Active species capture experiment and electron paramagnetic resonance(EPR)results showed that singlet oxygen(^(1)O_(2))was the main contributor for BPA abatement.The four possible degradation intermediates were confirmed by ultra-high-performance liquid chromatography-mass spectrometry,and possible degradation pathway was proposed.The estrogenic activity of treated solution was reduced by MCF-7cell viability evaluation.