Chem. J. Chinese Universities ›› 2024, Vol. 45 ›› Issue (1): 20230410.doi: 10.7503/cjcu20230410

• Physical Chemistry • Previous Articles     Next Articles

Functional Regulation and Mechanism of Phosphoric Acid in GO Intercalation Stage

WANG Jiarui1, LI Chunli1,2(), CHENG Jiahao1, HAO Yaling1, ZHOU Nan1, YANG Peng1   

  1. 1.Resource and Environmental Engineering College
    2.Key Laboratory of Environmental Pollution Control and Restoration of Colleges and Universities in Autonomous Region,Inner Mongolia University of Technology,Hohhot 010000,China
  • Received:2023-09-15 Online:2024-01-10 Published:2023-10-26
  • Contact: LI Chunli E-mail:lichunli16@163.com
  • Supported by:
    the Inner Mongolia Natural Science Foundation, China(2023LHMS05020);the Basic Scientific Research Business Fee Project of Universities Directly Under the Autonomous Region, China(JY20220042)

Abstract:

The research on the regulation and mechanism of the intercalation stage in the preparation of graphene oxide(GO) is of great significance for the functionalization of GO and its application in electrode materials. On the basis of the improved Hummers method, different volumes of H3PO4 were added to the H2SO4 intercalation agent to prepare GO with different oxidation degrees. Scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS), Fourier transform infrared spectroscopy(FTIR) and other characterization methods were used to analyze the microstructure, elemental composition and oxidation degree of different GO to explore the mechanism of H3PO4 in the process of intercalation of graphite. The electrochemical properties of GO under different volumes of H3PO4 were tested by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). The effect of H3PO4 on the electrochemical properties of GO was analyzed to achieve the purpose of improving the conductivity of GO by regulating the intercalation oxidation of graphite. The results show that the single H2SO4 causes the excessive oxidation of the ortho-diol on the GO base surface to cause holes. The addition of H3PO4 will expand the graphite layer spacing and make the oxidant easier to enter the graphite layer and react with 1,2-diol to form a ring structure to protect the base surface, thereby improving the conductivity of GO. As an auxiliary acid, H3PO4 will assist H2SO4 to prepare GO with more complete base surface and higher oxidation degree, but its acidity is weak and cannot completely replace the role of H2SO4 in the oxidation process. The research results provide experimental support and theoretical support for the subsequent development of functionalized GO and its application in energy storage.

Key words: Graphene oxide, Phosphoric acid intercalation, Mechanism research, Electrochemistry, Chemical reaction, Partial oxidation

CLC Number: 

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