title: Knitting the catalytic pattern of artificial photosynthesis to a hybrid graphene nanotexture.
abstract: The artificial leaf project calls for new materials enabling multielectron catalysis with minimal overpotential, high turnover frequency, and long-term stability. Is graphene a better material than carbon nanotubes to enhance water oxidation catalysis for energy applications? Here we show that functionalized graphene with a tailored distribution of polycationic, quaternized, ammonium pendants provides an sp(2) carbon nanoplatform to anchor a totally inorganic tetraruthenate catalyst, mimicking the oxygen evolving center of natural PSII. The resulting hybrid material displays oxygen evolution at overpotential as low as 300 mV at neutral pH with negligible loss of performance after 4 h testing. This multilayer electroactive asset enhances the turnover frequency by 1 order of magnitude with respect to the isolated catalyst, and provides a definite up-grade of the carbon nanotube material, with a similar surface functionalization. Our innovation is based on a noninvasive, synthetic protocol for graphene functionalization that goes beyond the ill-defined oxidation-reduction methods, allowing a definite control of the surface properties.
authors.affiliation: Center of Excellence for Nanostructured Materials (CENMAT) and INSTM, unit of Trieste, Dipartimento di Scienze Chimiche e Farmaceutiche, University of Trieste, Piazzale Europa 1, I-34127 Trieste, Italy.
authors.forename: Mildred
authors.initials: M
authors.lastname: Quintana
authors.forename: Alejandro Montellano
authors.initials: AM
authors.lastname: López
authors.forename: Stefania
authors.initials: S
authors.lastname: Rapino
authors.forename: Francesca Maria
authors.initials: FM
authors.lastname: Toma
authors.forename: Matteo
authors.initials: M
authors.lastname: Iurlo
authors.forename: Mauro
authors.initials: M
authors.lastname: Carraro
authors.forename: Andrea
authors.initials: A
authors.lastname: Sartorel
authors.forename: Chiara
authors.initials: C
authors.lastname: Maccato
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Ke
authors.forename: Carla
authors.initials: C
authors.lastname: Bittencourt
authors.forename: Tatiana
authors.initials: T
authors.lastname: Da Ros
authors.forename: Gustaaf
authors.initials: G
authors.lastname: Van Tendeloo
authors.forename: Massimo
authors.initials: M
authors.lastname: Marcaccio
authors.forename: Francesco
authors.initials: F
authors.lastname: Paolucci
authors.forename: Maurizio
authors.initials: M
authors.lastname: Prato
authors.forename: Marcella
authors.initials: M
authors.lastname: Bonchio
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry* / Q000528:radiation effects; D006108:Graphite / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D045332:Photosystem II Protein Complex; C113691:photosystem II, PSII-X subunit; D006108:Graphite