Synthesis of MnO2 nanosheets on montmorillonite for oxidative degradation and adsorption of methylene blue

Yi He; De Bin Jiang; Jie Chen; De Yi Jiang; Yu Xin Zhang

doi:10.1016/j.jcis.2017.09.066

Synthesis of MnO₂ nanosheets on montmorillonite for oxidative degradation and adsorption of methylene blue

J Colloid Interface Sci. 2018 Jan 15:510:207-220. doi: 10.1016/j.jcis.2017.09.066. Epub 2017 Sep 18.

Authors

Yi He¹, De Bin Jiang², Jie Chen³, De Yi Jiang¹, Yu Xin Zhang⁴

Affiliations

¹ College of Resources and Environmental Science, State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, PR China.
² State Key Laboratory of Mechanical Transmissions, College of Materials Science and Engineering, Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology, Chongqing University, Chongqing 400044, PR China.
³ College of Resources and Environmental Science, State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, PR China. Electronic address: chenjie_cqu@163.com.
⁴ College of Resources and Environmental Science, State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, PR China; State Key Laboratory of Mechanical Transmissions, College of Materials Science and Engineering, Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology, Chongqing University, Chongqing 400044, PR China. Electronic address: zhangyuxin@cqu.edu.cn.

PMID: 28942171
DOI: 10.1016/j.jcis.2017.09.066

Abstract

In this research, MnO₂ nanosheets on montmorillonite (MnO₂ nanosheets@MMt) was synthesized by one-pot hydrothermal method and characterized by X-ray diffraction, Fourier transform infrared spectra, nitrogen adsorption and scanning electron microscopy. It was found that honeycomb-like MnO₂ nanosheets vertically grew on the surface of montmorillonite. MnO₂ nanosheets@MMt exhibited high methylene blue (MB) removal rate, which reached 97.7% within 5min under the condition of pH 2, MnO₂ nanosheets dosage of 0.1gL^-1 and initial dye concentration of 10mgL^-1. Additionally, the influencing factors such as pH value, amount of MnO₂ nanosheets@MMt, and MB concentration were also investigated in this paper. Results showed the MB degradation process was correlated with pH value, and the MnO₂ nanosheets@MMt achieved MB removal rate of 92.8% within 5min under pH 11 because of its absorption capacity of MB. The kinetics of the adsorption process complied with the Pseudo-second-order model. The Langmuir model was found to be the most suitable for describing the experimental equilibrium data of MnO₂ nanosheets@MMt. The MnO₂ nanosheets@MMt showed high adsorption capacity of 363.63mgg^-1 for MB dye. The oxidative decomposition of MB was conducted in the presence of MnO₂ nanosheets@MMt in the low pH, finding that the lower the pH was, the faster the degradation rate was. This research demonstrates that MnO₂ nanosheets@MMt has potential applications in wastewater treatment.

Keywords: Degradation; MMt; MnO(2); Nanocomposites.