Synthesis of nano-octahedral MgO via a solvothermal-solid-decomposition method for the removal of methyl orange from aqueous solutions

Xirui Yan; Zixin Tian; Wencai Peng; Jianshu Zhang; Yanbin Tong; Jun Li; Dekui Sun; Hui Ge; Jinli Zhang

doi:10.1039/c9ra10296e

Synthesis of nano-octahedral MgO via a solvothermal-solid-decomposition method for the removal of methyl orange from aqueous solutions

RSC Adv. 2020 Mar 13;10(18):10681-10688. doi: 10.1039/c9ra10296e. eCollection 2020 Mar 11.

Authors

Xirui Yan¹, Zixin Tian¹, Wencai Peng^{1

2}, Jianshu Zhang^{1

2}, Yanbin Tong¹, Jun Li³, Dekui Sun⁴, Hui Ge⁴, Jinli Zhang^{1

5}

Affiliations

¹ School of Chemistry and Chemical Engineering, Shihezi University Shihezi 832003 Xinjiang China pengwencai@shzu.edu.cn junli@ipe.ac.cn.
² Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan Shihezi Xinjiang China.
³ State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 China.
⁴ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences Taiyuan Shanxi China.
⁵ Key Laboratory for Systems Bioengineering MOE, Tianjin University, Collaborative Innovation Centre of Chemical Science and Chemical Engineering (Tianjin) Tianjin 300072 China.

Abstract

Nano magnesium oxide has wide applications, and MgO with (111) facets has wider potential applications than MgO with (100) facets (e.g., in catalysis and adsorption). However, nano MgO with (111) polar faces has not been studied throughly, so the preparation of nano-octahedral MgO (N-O-MgO) with eight exposed (111) facets remains a great challenge. Herein, we successfully synthesised N-O-MgO via an effective solvothermal-solid-decomposition method and studied its adsorption performance. The obtained N-O-MgO showed excellent performance (229.36 mg g^-1) for methyl orange (MO). The adsorption follows the pseudo-second-order kinetic equation and the Langmuir isotherm model. The dimensionless parameter R _L (0.042) and Gibbs free energy ΔG (-6.538 kJ mol^-1) revealed that the adsorption of MO on N-O-MgO was a spontaneous and feasible process. The adsorption of MO and methyl blue (MB) on N-O-MgO were studied to determine the adsorption sites. Based on these experiments and analysis, it was determined that the adsorption sites were magnesium ions and the adsorption mechanism was proposed to describe the adsorption process.