Graphene oxide-monohydrated manganese phosphate composites: Preparation via modified Hummers method

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 547; pp. 56 - 63
• Main Authors: Yuan, Rui, Yuan, Jing, Wu, Yanping, Ju, Pengfei, Ji, Li, Li, Hongxuan, Chen, Lei, Zhou, Huidi, Chen, Jianmin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.06.2018
• Subjects: Computer simulation; Graphene oxide-MnPO4·H2O; Reduced GO-Mn2P2O7; Computer simulation; Reduced GO-Mn2P2O7; Graphene oxide-MnPO4·H2O
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2018.03.023

[Display omitted] A modified Hummers method was established to prepare graphene oxide-MnPO4·H2O (denoted as GO-MnPO4·H2O) composites. Findings indicate that the as-formed GO-MnPO4·H2O particles are of a petal-shape and exhibit a uniform size of ∼1.2 μm, and they are stable and remain nearly unchanged after 2 day of standing at 30 ℃ in air. The formation mechanism was investigated by computer simulations in combination with experimental explorations. The Mn2+ ions obtained by oxidation reaction can be distributed around the oxygen-containing functional groups of GO (especially for hydroxyl) and interact with them via electrostatic forces or coordination bonds. The as-formed GO-Mn2+ dipolar pair can further act as the anchor sites to facilitate the growth of MnPO4·H2O. During the formation of GO-MnPO4·H2O composites, MnPO4·H2O species contributes to promoting the exfoliation of GO sheets. Moreover, the polycrystalline structure of GO-MnPO4·H2O aggregates is destroyed heavily under 450 °C, and they can be decomposed to generate reduced GO-Mn2P2O7 (denoted as rGO-Mn2P2O7) after 900 ℃ treatment in N2 atmosphere. This methodology made the synthesis of GO-MnPO4·H2O and rGO-Mn2P2O7 composites possible and may be further extended to prepare more complicated nanocomposites based on GO sheets for technological applications.