title: Transition-metal-ion-mediated polymerization of dopamine: mussel-inspired approach for the facile synthesis of robust transition-metal nanoparticle-graphene hybrids.
abstract: Inspired by the high transition-metal-ion content in mussel glues, and the cross-linking and mechanical reinforcement effects of some transition-metal ions in mussel threads, high concentrations of nickel(II), cobalt(II), and manganese(II) ions have been purposely introduced into the reaction system for dopamine polymerization. Kinetics studies were conducted for the Ni(2+)-dopamine system to investigate the polymerization mechanism. The results show that the Ni(2+) ions could accelerate the assembly of dopamine oligomers in the polymerization process. Spectroscopic and electron microscopic studies reveal that the Ni(2+) ions are chelated with polydopamine (PDA) units, forming homogeneous Ni(2+)-PDA complexes. This facile one-pot approach is utilized to construct transition-metal-ion-PDA complex thin coatings on graphene oxide, which can be carbonized to produce robust hybrid nanosheets with well-dispersed metallic nickel/metallic cobalt/manganese(II) oxide nanoparticles embedded in PDA-derived thin graphitic carbon layers. The nickel-graphene hybrid prepared by using this approach shows good catalytic properties and recyclability for the reduction of p-nitrophenol.
authors.affiliation: Institute of Chemical and Engineering Sciences, A*STAR (Agency for Science, Technology and Research), 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore).
authors.forename: Liping
authors.initials: L
authors.lastname: Yang
authors.forename: Junhua
authors.initials: J
authors.lastname: Kong
authors.forename: Dan
authors.initials: D
authors.lastname: Zhou
authors.forename: Jia Ming
authors.initials: JM
authors.lastname: Ang
authors.forename: Si Lei
authors.initials: SL
authors.lastname: Phua
authors.forename: Wu Aik
authors.initials: WA
authors.lastname: Yee
authors.forename: Hai
authors.initials: H
authors.lastname: Liu
authors.forename: Yizhong
authors.initials: Y
authors.lastname: Huang
authors.forename: Xuehong
authors.initials: X
authors.lastname: Lu
mesh_terms: D000818:Animals; D049872:Bivalvia; D004298:Dopamine / Q000378:metabolism*; D006108:Graphite / Q000138:chemical synthesis* / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D058105:Polymerization
chemical_list: D006108:Graphite; D004298:Dopamine
keywords: catalysis; dopamines; graphene; hybrid materials; transition metals