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Abstract: A synergistic effect resulting from the interaction of small (2.4–3.1 nm) naked Pt nanoparticles (NPs) imprinted on N‐doped carbon supports is evidenced by structural, electronic and electrochemical characterization. The size and distribution of the sputtered Pt NPs are found to be related to the nature of the support because Pt NPs are preferentially located at Ngraphitic sites. In addition, Rutherford backscattering shows that a deeper penetration of the Pt NPs is obtained in the N‐doped carbon support with larger pore diameters. The ligand effect of the N‐doped carbon supports is found to occur by electron donation from Npyrrolic and Ngraphitic sites to the Pt NPs and the electron acceptor behavior of the C=Npyridinic sites. The carbon matrix acquires a basic characteristic (electron‐richer, metallic behavior) capable of interacting with metallic NPs akin to a bimetallic‐like system. The imprinted Pt NPs are active catalysts for oxidation, although displaying poor catalytic activity for reduction reactions. The catalyst N‐doped carbon supports play an important role in the overall catalytic process, rather than only acting as a simple active phase carrier. [ABSTRACT FROM AUTHOR]

In this work, poly[2,7-(9,9-bis(2-ethylhexyl)-dibenzosilole)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PSiF-DBT) was used as active layer in bilayer solar cell with C60 as electron acceptor. As cast devices already show reasonable power conversion efficiency (PCE) that increases to 4% upon annealing at 100 ℃C. Space charge limited measurements of the hole mobility (l) in PSiF-DBT give μ~1.0×10-4 cm²/(V s) which does not depend on the temperature of the annealing treatment. Moreover, positron annihilation spectroscopy experiments revealed that PSiFDBT films are well stacked even without the thermal treatment. The variations in the transport of holes upon annealing are then small. As a consequence, the PCE rise was mainly induced by the increase of the polymer surface roughness that leads to a more effective interface for exciton dissociation at the PSiF-DBT/fullerene heterojunction. [ABSTRACT FROM AUTHOR]

In this work, poly[2,7-(9,9-bis(2-ethylhexyl)-dibenzosilole)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PSiF-DBT) was used as active layer in bilayer solar cell with C60 as electron acceptor. As cast devices already show reasonable power conversion efficiency (PCE) that increases to 4% upon annealing at 100 ℃C. Space charge limited measurements of the hole mobility (l) in PSiF-DBT give μ~1.0×10-4 cm²/(V s) which does not depend on the temperature of the annealing treatment. Moreover, positron annihilation spectroscopy experiments revealed that PSiFDBT films are well stacked even without the thermal treatment. The variations in the transport of holes upon annealing are then small. As a consequence, the PCE rise was mainly induced by the increase of the polymer surface roughness that leads to a more effective interface for exciton dissociation at the PSiF-DBT/fullerene heterojunction. [ABSTRACT FROM AUTHOR]

A synergistic effect resulting from the interaction of small (2.4-3.1 nm) naked Pt nanoparticles (NPs) imprinted on N-doped carbon supports is evidenced by structural, electronic and electrochemical characterization. The size and distribution of the sputtered Pt NPs are found to be related to the nature of the support because Pt NPs are preferentially located at N graphitic sites. In addition, Rutherford backscattering shows that a deeper penetration of the Pt NPs is obtained in the N-doped carbon support with larger pore diameters. The ligand effect of the N-doped carbon supports is found to occur by electron donation from N pyrrolic and N graphitic sites to the Pt NPs and the electron acceptor behavior of the C=N pyridinic sites. The carbon matrix acquires a basic characteristic (electron-richer, metallic behavior) capable of interacting with metallic NPs akin to a bimetallic-like system. The imprinted Pt NPs are active catalysts for oxidation, although displaying poor catalytic activity for reduction reactions. The catalyst N-doped carbon supports play an important role in the overall catalytic process, rather than only acting as a simple active phase carrier., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)