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Green and Effective Removal of Aqueous Graphene Oxide under UV-Light Irradiation

Authors :
Xiaoya Yuan
Dong Peng
Qiuye Jing
Jiawei Niu
Xin Cheng
Zijuan Feng
Xue Wu
Source :
Nanomaterials, Vol 8, Iss 9, p 654 (2018)
Publication Year :
2018
Publisher :
MDPI AG, 2018.

Abstract

The potential extensive application of graphene oxide (GO) in various fields results in the possibility of its release into the natural environment with negative impacts on humans and the ecosystem. The UV-induced removal behavior of aqueous GO was evaluated in this study, and the effect of various parameters (including initial GO concentration, initial solution pH and co-existing ions) on removal rate of GO were investigated in detail. The results showed that UV-light induced a maximum removal rate of GO of 99.1% after 32 h irradiation without any additives, and that the photo-induced removal process in all cases fitted well with pseudo-first-order kinetics. Under optimal conditions, GO was completely removed, with initial GO concentrations of 10 mg/L while adjusting solution pH to 3 or adding Ca2+-containing salt. The GO and photoreduced graphene oxide (prGO) were characterized using High-resolution Transmission Microscopy (HRTEM), X-ray Photoelectron Spectroscopy (XPS), and Fourier-transform Infrared Spectroscopy (FT-IR). The radical species trapping experiments and Electron Spin Resonance (ESR) tests indicated that self-reduction of GO upon UV-light exposure could be achieved via photogenerated electrons from a GO semiconductor. Further mechanism study showed that the high efficiency of UV-induced GO removal came from UV-induced photoreduction, and pH-induced or cation-induced coagulation. This study provided a green and effective method to remove GO from aqueous solutions.

Details

Language :
English
ISSN :
20794991
Volume :
8
Issue :
9
Database :
Directory of Open Access Journals
Journal :
Nanomaterials
Publication Type :
Academic Journal
Accession number :
edsdoj.2b6a6857414efaa18de4e3b469e6ce
Document Type :
article
Full Text :
https://doi.org/10.3390/nano8090654