title: Complex Roles of Solution Chemistry on Graphene Oxide Coagulation onto Titanium Dioxide: Batch Experiments, Spectroscopy Analysis and Theoretical Calculation.
abstract: Although graphene oxide (GO) has been used in multidisciplinary areas due to its excellent physicochemical properties, its environmental behavior and fate are still largely unclear. In this study, batch experiments, spectroscopy analysis and theoretical calculations were addressed to promote a more comprehensive understanding toward the coagulation behavior of GO onto TiO2under various environmental conditions (pH, co-existing ions, temperature, etc.). The results indicated that neutral pH was beneficial to the removal of GO due to the electrostatic interaction. The presence of cations accelerated GO coagulation significantly owing to the influence of electrical double layer compression. On the contrary, the presence of anions improved the stability of GO primarily because of electrostatic repulsion and steric hindrance. Results of XRD, FTIR and XPS analysis indicated that the coagulation of GO on TiO2was mainly dominated by electrostatic interactions and hydrogen bonds, which were further evidenced by DFT calculations. The high binding energy further indicated the stability of GO + TiO2system, suggesting that TiO2can be used as an effective coagulant for the efficient elimination and coagulation of GO from aqueous solutions. These findings might likely lead to a better understanding of the migration and transformation of carbon nanomaterials in the natural environment.
authors.affiliation: School of Environment and Chemical Engineering, North China Electric Power University, Beijing, 102206, P.R. China.|University of Science and Technology of China, Jinzhai road 96, Hefei, 230000, P.R. China.
authors.forename: Shujun
authors.initials: S
authors.lastname: Yu
authors.affiliation: School of Environment and Chemical Engineering, North China Electric Power University, Beijing, 102206, P.R. China.|University of Science and Technology of China, Jinzhai road 96, Hefei, 230000, 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.|University of Science and Technology of China, Jinzhai road 96, Hefei, 230000, P.R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: University of Science and Technology of China, Jinzhai road 96, Hefei, 230000, P.R. China.
authors.forename: Tongtong
authors.initials: T
authors.lastname: Yang
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 Environment and Chemical Engineering, North China Electric Power University, Beijing, 102206, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wen
authors.affiliation: School of Environment and Chemical Engineering, North China Electric Power University, Beijing, 102206, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: Tasawar
authors.initials: T
authors.lastname: Hayat
authors.affiliation: NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Alsaedi
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