溶剂热后处理对石墨相氮化碳光化学固氮产氨性能的影响（英文）

发布时间：2018-07-12 09:02

本文选题：石墨相氮化碳 + 离子液体　；参考：《物理化学学报》2017年03期

【摘要】：采用离子液体[Bmim]Br为溶剂,溶剂热后处理法制备了具有大比表面积和氮空穴的石墨相氮化碳催化剂。采用X射线衍射(XRD)光谱、扫描电镜(SEM)、氮气吸附、紫外-可见(UV-Vis)光谱、X射线光电子能谱(XPS)、荧光光谱(PL)、电子顺磁共振谱(EPR)、程序升温脱附(TPD)等分析手段对制备的催化剂进行了表征。结果表明经过溶剂热后处理的催化剂形貌由无规则的层状结构变为尺寸为30-40 nm的纳米颗粒,导致比表面积从8.6 m~2?g~(-1)增加到37.9 m~2?g~(-1)。从N_2-TPD、荧光光谱及密度泛函理论(DFT)模拟计算的结果得出,氮空穴不仅能捕获光生电子促进电子空穴的有效分离,还能吸附并活化反应物氮气分子。溶剂热处理后,增加的比表面积导致更多的氮空穴作为反应活性位暴露在催化剂表面,是固氮活性显著提高。本文还探讨了可能的反应机理。
[Abstract]:Graphite phase carbon nitride catalyst with large specific surface area and nitrogen hole was prepared by solvothermal post-treatment using ionic liquid [Bmim] Br as solvent. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption, UV-Vis spectroscopy (XPS), fluorescence spectroscopy (PL), electron paramagnetic resonance (EPR) and temperature programmed desorption (TPD). The results show that the morphology of the catalyst after solvothermal treatment changes from an irregular layered structure to a size of 30-40 nm nanoparticles, resulting in an increase in the specific surface area from 8.6 mg ~ (-1) to 37.9 m ~ (2) G ~ (-1). The results of NSP, fluorescence spectra and density functional theory (DFT) simulation show that nitrogen holes can not only capture photogenerated electrons to promote the effective separation of electron holes, but also adsorb and activate nitrogen molecules. After solvent heat treatment, the increase of specific surface area resulted in more nitrogen holes being exposed to the catalyst surface as reactive sites, which resulted in a significant increase in nitrogen fixation activity. The possible reaction mechanism is also discussed.
【作者单位】：辽宁石油化工大学化学化工与环境学部;
【基金】：supported by the National Natural Science Foundation of China(41571464) Education Department of Liaoning Province,China(L2014145) Natural Science Foundation of Liaoning Province,China(201602467)~~
【分类号】：O643.36

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