Carbonaceous materials are considered as potential adsorbents for organic dyes due to their unique structures which provide high aspect ratios, hydrophobic property, large efficient surface area, and easy surface modification. In this work, graphene nanoribbons (GNRs) were prepared by atomic hydrogen-induced treatment of single-walled carbon nanotube (SWCNTs), which inspire the idea of cutting and unzipping the SWCNTs carpets with the modified in molecules prevent because of the unfolding of the side-walls. The unfolded spaces and uniform vertical arrangement not only enhance the active surface area, but also promote the electrostatic and π–π interactions between dyes and GNRs. The improved adsorption capacity of GNRs beyond original SWCNTs can be determined by the adsorption kinetics and isotherm, which are evaluated through adsorption batch experiments of the typical cationic methylene blue (MB) and anionic orange II (OII) dye, respectively. It is shown that the adsorption kinetics follow a pseudo second-order model while the adsorption isotherm could be determined by Langmuir model. The results reveal that the maximum adsorption capacities of GNRs for MB and OII are 280 and 265 mg/g, respectively. The GNRs present the highly efficient, cost effective, and environmental friendly properties for the commercial applications of wastewater treatment.

    Abstract
    Graphic abstract
    1 Introduction
    2 Experimental section
        2.1 Preparation of VA-GNR
        2.2 Sample characterization
    3 Results and discussion
        3.1 Adsorption kinetics
        3.2 Adsorption isotherm
    4 Conclusion
    Acknowledgements 
    References

• Yan Gao(Department of Physics, Shanxi Datong University, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Collaborative Innovation Center of Extreme Optics, Shanxi University)
• Xilong Liang(State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Collaborative Innovation Center of Extreme Optics, Shanxi University)
• Shuangping Han(State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Collaborative Innovation Center of Extreme Optics, Shanxi University)
• Liang Wu(Department of Physics, Shanxi Datong University)
• Guofeng Zhang(State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Collaborative Innovation Center of Extreme Optics, Shanxi University)
• Chengbing Qin(State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Collaborative Innovation Center of Extreme Optics, Shanxi University)
• Shanxia Bao(Department of Physics, Shanxi Datong University)
• Qiang Wang(Department of Physics, Shanxi Datong University)
• Lele Qi(Department of Physics, Shanxi Datong University)
• Liantuan Xiao(State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Collaborative Innovation Center of Extreme Optics, Shanxi University)