Nuclear Techniques ›› 2015, Vol. 38 ›› Issue (3): 30101-030101.doi: 10.11889/j.0253-3219.2015.hjs.38.030101

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS •     Next Articles

Study of the interaction between graphene oxide and humic acid by synchrotron radiation circular dichroism spectroscopy

ZHOU Xiaoyan1 WANG Bing1 CHEN Hanqing1 WANG Hailong1 TAO Ye2 OUYANG Hong1 FENG Weiyue1   

  1. 1(Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China) 2(Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China)
  • Received:2014-12-22 Revised:2015-01-19 Online:2015-03-10 Published:2015-03-09

Abstract: Background: Graphene Oxide (GO) is a type of two-dimension carbon nanomaterial with promising environmental application due to its good solubility in water, high absorbability and catalytic activity. Humic Acid (HA) is the main component of Natural Organic Matter (NOM) in water, which could be adsorbed on the surface of GO nanosheets via π-π interaction and then affect the physicochemical properties of GO in aqueous system. Purpose: Investigating the interaction between GO and HA will provide some insights for environmental application of GO. Methods: We employed Synchrotron Radiation Circular Dichroism spectroscopy (SRCD), Ultraviolet-Visible spectroscopy (UV-Vis) and Fourier Transform Infrared spectroscopy (FTIR) to explore the interaction between GO and HA under different mass ratio of HA to GO, environmental pH and temperature. Results & Conclusion: UV-Vis spectroscopy of GO-HA showed that the intensity of the absorption peak at 228 nm gradually increased when the mass ratio of HA to GO increased to 4:1 from 1:4 and the FTIR C-O stretching vibration shifted and decreased, indicating the strong π-π interaction and hydrogen bonding between GO and HA. GO showed a broad peak at about 240 nm in SRCD spectra which origin from its surface O-containing functional groups, folding or curl of the nanosheets. SRCD indicated the interaction between GO and HA could change the dispersion behavior of GO and then affect CD activity of GO-HA, depending on the mass ratio of HA to GO, environmental pH and temperature. GO-HA showed higher CD activity with the increased pH and decreased temperature (4 °C) due to the increase of folding state.

Key words: Graphene Oxide (GO), Humic Acid (HA), Interaction, Synchrotron Radiation Circular Dichroism spectroscopy (SRCD)