tailieunhanh - Báo cáo hóa học: " Influences of graphene oxide support on the electrochemical performances of graphene oxide-MnO2 nanocomposites"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Influences of graphene oxide support on the electrochemical performances of graphene oxide-MnO2 nanocomposites | Yang et al. Nanoscale Research Letters 2011 6 531 http content 6 1 531 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Influences of graphene oxide support on the electrochemical performances of graphene oxide-MnO2 nanocomposites 1 1 1 12 2 J I-1 1 3 Huanping Yang Jian Jiang Weiwei Zhou Linfei Lai Lifei Xi Yeng Ming Lam Zexiang Shen Bahareh Khezri and Ting Yu1 4 Abstract MnO2 supported on graphene oxide GO made from different graphite materials has been synthesized and further investigated as electrode materials for supercapacitors. The structure and morphology of MnO2-GO nanocomposites are characterized by X-ray diffraction X-ray photoemission spectroscopy scanning electron microscopy transmission electron microscopy Raman spectroscopy and Nitrogen adsorption-desorption. As demonstrated the GO fabricated from commercial expanded graphite denoted as GO 1 possesses more functional groups and larger interplane gap compared to the GO from commercial graphite powder denoted as GO 2 . The surface area and functionalities of GO have significant effects on the morphology and electrochemical activity of MnO2 which lead to the fact that the loading amount of MnO2 on GO 1 is much higher than that on GO 2 . Elemental analysis performed via inductively coupled plasma optical emission spectroscopy confirmed higher amounts of MnO2 loading on GO 1 . As the electrode of supercapacitor MnO2-GO 1 nanocomposites show larger capacitance F g-1 and better electrochemical activity than MnO2-GO 2 possibly due to the high loading good uniformity and homogeneous distribution of MnO2 on GO 1 support. Introduction As one of the green supercapacitor electrode materials MnO2 shows potential to replace RuO2 due to its high specific capacitance environmental compatibility low cost and abundance in nature. In general the fabrication of MnO2 can be readily realized on large scale using traditional chemical co-precipitation methods 1 2 . .