title: Coagulation Behavior of Graphene Oxide on Nanocrystallined Mg/Al Layered Double Hydroxides: Batch Experimental and Theoretical Calculation Study.
abstract: Graphene oxide (GO) has attracted considerable attention because of its remarkable enhanced adsorption and multifunctional properties. However, the toxic properties of GO nanosheets released into the environment could lead to the instability of biological system. In aqueous phase, GO may interact with fine mineral particles, such as chloridion intercalated nanocrystallined Mg/Al layered double hydroxides (LDH-Cl) and nanocrystallined Mg/Al LDHs (LDH-CO3), which are considered as coagulant molecules for the coagulation and removal of GO from aqueous solutions. Herein the coagulation of GO on LDHs were studied as a function of solution pH, ionic strength, contact time, temperature and coagulant concentration. The presence of LDH-Cl and LDH-CO3 improved the coagulation of GO in solution efficiently, which was mainly attributed to the surface oxygen-containing functional groups of LDH-Cl and LDH-CO3 occupying the binding sites of GO. The coagulation of GO by LDH-Cl and LDH-CO3 was strongly dependent on pH and ionic strength. Results of theoretical DFT calculations indicated that the coagulation of GO on LDHs was energetically favored by electrostatic interactions and hydrogen bonds, which was further evidenced by FTIR and XPS analysis. By integrating the experimental results, it was clear that LDH-Cl could be potentially used as a cost-effective coagulant for the elimination of GO from aqueous solutions, which could efficiently decrease the potential toxicity of GO in the natural environment.
authors.affiliation: School of Environment and Chemical Engineering, North China Electric Power University , Beijing 102206, P. R. China.|School of Chemistry, Biological and Materials Sciences, East China Institute of Technology , Nanchang, 330013, P. R. China.
authors.forename: Yidong
authors.initials: Y
authors.lastname: Zou
authors.affiliation: School of Environment and Chemical Engineering, North China Electric Power University , Beijing 102206, P. R. China.|Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Science , P.O. Box 1126, Hefei, 230031, P.R. China.
authors.forename: Xiangxue
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Environment and Chemical Engineering, North China Electric Power University , Beijing 102206, P. R. China.
authors.forename: Yuejie
authors.initials: Y
authors.lastname: Ai
authors.affiliation: School of Chemistry, Biological and Materials Sciences, East China Institute of Technology , Nanchang, 330013, P. R. China.
authors.forename: Yunhai
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Science , P.O. Box 1126, Hefei, 230031, P.R. China.|Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences, Soochow University , 215123, Suzhou, P.R. China.
authors.forename: Jiaxing
authors.initials: J
authors.lastname: Li
authors.affiliation: Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology , Roslagstullsbacken 15, 10691 Stockholm, Sweden.
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Ji
authors.affiliation: School of Environment and Chemical Engineering, North China Electric Power University , Beijing 102206, P. R. China.|NAAM Research Group, Faculty of Science, King Abdulaziz University , Jeddah 21589, Saudi Arabia.
authors.forename: Xiangke
authors.initials: X
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry; D006108:Graphite / Q000737:chemistry* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D008276:Magnesium Hydroxide / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D012996:Solutions / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D010087:Oxides; D012996:Solutions; D014874:Water Pollutants, Chemical; D000536:Aluminum Hydroxide; D006108:Graphite; D008276:Magnesium Hydroxide