【摘要】 采用煅烧法制备了以木质素生物炭为载体的单原子催化剂（Ni-N-C-10）,用于高效活化过硫酸盐（PMS）降解苯酚.利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、经球差校正的高角度环形暗场扫描透射电子显微镜（AC-HAADF-STEM）、X射线粉末衍射仪（XRD）以及X射线光电子能谱仪（XPS）等对材料进行了表征分析,证明合成了原子分散的催化剂Ni-N-C-10.探究了制备过程中双氰胺的投加量和降解实验中催化剂投加量、PMS投加量、pH值以及温度对苯酚降解的影响.结果表明,在催化剂制备过程中,加入10倍质量比的双氰胺更有利于实现原子分散. Ni-N-C-10/PMS体系在较低的催化剂和PMS投加量、以及较宽的pH值范围（3～9）内都能有效活化PMS降解苯酚.此外,该体系的稳定性好且应用范围广,除了能高效降解苯酚外还能快速降解双酚A、四环素和亚甲基蓝.电子顺磁共振检测和自由基淬灭实验结果表明, Ni-N-C-10/PMS体系降解苯酚为SO₄^·-、·OH和¹O₂3种主要活性物种共同作用的结果,其中1O2起主导作用.反应前后Ni-N-C-10催化剂的XPS分析结果表明,催化降解苯酚的效率与Ni位点呈正相关.更多还原

【Abstract】 A single atom catalyst（Ni-N-C-10）supported on lignin biochar was prepared via calcination method,which was used to activate peroxymonosulfate（PMS）to degrade phenol. The prepared catalysts were characterized by means of scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray powder diffraction（XRD）,N₂ adsorption-desorption analysis and X-ray photoelectron spectroscopy（XPS）. It was proved that the atom dispersed catalyst Ni-N-C-10 was synthesized. The effects of dicyandiamide dosage in the preparation process,catalyst dosage,PMS dosage,pH value and temperature on phenol degradation were also studied. The results showed that the addition of dicyandiamide 10 times the weight of lignin was more conducive to the atom dispersion. Besides,Ni-N-C-10/PMS system could effectively activate PMS and degrade phenol at lower catalyst and PMS dosage in a wide range of pH（3―9）. In addition to efficient degradation of phenol,it could also rapidly degrade a variety of organic pollutants such as p-chlorophenol,bisphenol A,tetracycline and methylene blue. EPR detection and radical quenching experiments showed that ¹O₂ acted as the dominant active specie in the Ni-N-C-10/PMS system for phenol degradation. The XPS analysis of Ni-N-C-10 catalyst before and after the reaction showed that the catalytic degradation efficiency of the catalyst was positively correlated with Ni site. This work proves that the Ni-N-C-10/PMS system could efficiently degrade the phenol in water and has potential applications.更多还原