CaCl_2催化NaBH_4还原氧化石墨烯(英文)

A simple method for the reduction of graphene oxide by sodium borohydride with CaCl_2 as a catalyst

以Ca Cl2作为催化剂、Na BH4为还原剂,还原氧化石墨烯。还原反应能在室温下进行,并以去离子水作为唯一的溶剂,此法是一种低能耗、环保并简易的方法。通过红外光谱、紫外光谱、X射线光电子能谱、表面电阻测量手段研究Ca Cl2添加量对氧化石墨烯还原程度的影响。采用透射电子显微镜和原子力显微镜观察氧化石墨烯和还原氧化石墨烯的形貌。结果表明,以氯化钙作为催化剂还原氧化石墨烯,能更有效地去除氧化石墨烯表面的含氧官能团,提高还原氧化石墨烯的导电性。当Ca Cl2添加浓度达到50 mmol/L时,还原氧化石墨烯C/O比达到5.38,表面电阻达到18.6 kΩ/sq。

Graphene oxide（GO） prepared by a modified Hummers method was reduced by NaBH4 at room temperature for 12 h in a 0.5 mg/mL GO water suspension to obtain reduced GO（RGO）,using CaCl2 as a catalyst.The GO and RGO were characterized by XPS,FT-IR,UV-Vis and electrical resistivity measurements.Results show that CaCl2 improves the reduction ability of NaBH4 for oxygen-containing functional groups on the GO.After reduction,the C/O atomic ratio increased,most of the oxygencontaining functional groups were eliminated,and the electrical resistance decreased significantly.The highest C/O atomic ratio was5.38 and the lowest electrical resistance of RGO was 18.6 kΩ/sq,the latter being about two orders of magnitudes lower than the RGO prepared without CaCl2.This reduction method opens a possibility of reducing GO under ambient conditions without using a toxic/corrosive reducing agent and an organic solvent.