Ni@C/CN纳米催化剂用于降解芳香族硝基化合物和有毒有机染料

Ni@C/CN nanocatalysts for aromatic degradation nitro compounds and toxic organic dyes

采用电弧放电法结合热解技术设计并合成了Ni@C/CN纳米催化剂。采用透射电镜、X射线衍射、X射线光电子能谱、电化学工作站对Ni@C/CN的微观结构和电子传输能力进行了研究;利用紫外-可见分光光度计研究了所制备的催化剂对芳香族硝基化合物(对硝基苯酚(4-NP)和有机染料(亚甲基兰))的催化还原性能。结果表明,Ni@C/CN纳米催化剂比Ni@C纳米胶囊具有更好的催化还原性能;通过优化Ni@C纳米胶囊和三聚氰胺的质量比可以优化Ni@C/CN的催化性能,优化后的Ni@C/CN催化还原降解4-NP和MB的准一级反应速率常数(k_(app))分别为4.656 min^(-1)和13.879 min^(-1);N的引入及异质C/CN壳层包覆金属Ni使Ni@C/CN获得良好的核壳协同作用,提高了Ni@C/CN的电子传输能力,同时,CN的表面缺陷增强了催化剂的吸附性能,增强了Ni@C/CN的催化还原能力。

Ni@C/CN nanocatalysts were designed and synthesized using the arc discharge method combined with the pyrolysis technique.Transmission electron microscopy(TEM),X-ray diffraction,XPS photoelectron spectroscopy,and electrochemical workstation were employed to investigate the microstructure and electron transport capacity of Ni@C/CN.Subsequently,the catalytic reduction properties of the prepared catalysts were evaluated against aromatic nitro compounds(p-nitrophenol(4-NP)and organic dyes(methylene blue(MB))using UV-visible spectrophotometer.The corresponding results showed that the Ni@C/CN nanocatalysts possessed better catalytic reduction properties than those of the Ni@C nanocapsules.The catalytic performance of Ni@C/CN could be regulated by optimizing the mass ratio of Ni@C nanocapsules and melamine,and its quasi-primary reaction rate constants(k_(app))for the catalytic reduction degradation of 4-NP and MB were 4.656 min^(-1) and 13.879 min^(-1),respectively.It was revealed that the introduction of N and the heterogeneous C/CN shell layer coated with metallic Ni resulted in good core-shell synergy and improved the electron transport capacity of Ni@C/CN,while the surface defects of CN enhanced the adsorption properties of the catalyst and enhanced the catalytic reduction of Ni@C/CN.