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State-of-the-art water-oxidation catalysts (WOCs) in acidic electrolytes usually contain expensive noble metals such as ruthenium and iridium. However, they too expensive to be implemented broadly in semiconductor photoanodes for photoelectrochemical (PEC) water splitting devices. Here, an Earth-abundant CoFe Prussian blue analogue (CoFe-PBA) is incorporated with core–shell Fe2O3/Fe2TiO5 type II heterojunction nanowires as composite photoanodes for PEC water splitting. Those deliver a high photocurrent of 1.25 mA cm−2 at 1.23 V versus reversible reference electrode in acidic electrolytes (pH = 1). The enhancement arises from the synergic behavior between the successive decoration of the hematite surface with nanolayers of Fe2TiO5 and then, CoFe-PBA. The underlying physical mechanism of performance enhancement through formation of the Fe2O3/Fe2TiO5/ CoFe-PBA heterostructure reveals that the surface states’ electronic levels of hematite are modified such that an interfacial charge transfer becomes kinetically favorable. These findings open new pathways for the future design of cheap and efficient hematite-based photoanodes in acidic electrolytes., This work was supported by the Spanish Ministerio de Economia y Competitividad (MINECO, Grants CTQ2015-71287-R, CTQ2015-71287-R, and CTQ2015-68770-R) and the coordinated Project ValPEC (ENE2017-85087-C3), the BIST Ignite Project inWOC2 and the Generalitat de Catalunya (2017 SGR 90, 2017 SGR 327, 2017 SGR 329, 2017 SGR 1246, and 2017 SGR 1406). ICN2 acknowledges the support from the Severo Ochoa Program (MINECO, Grant SEV-2017-0706). ICN2, ICIQ, and IREC are funded by the CERCA Programme/Generalitat de Catalunya. P.Y.T. acknowledges the scholarship support of DAAD short term grant. H.C.D. acknowledges support from the Deutsche Forschungsgemeinschaft (SFB 917). F.S.H. thanks the “LaCaixa”-Severo Ochoa International Programme (Programa internacional de Becas “LaCaixa”- Severo Ochoa) for a Ph.D. fellowship. P.P. and M.H. thank for the support by the Federal Ministry for Economic Affairs and Energy (BMWi) (Fundingregistration number: 03ET6080E). M.L. thanks the COST Action StableNextSol project MP1307, supported by COST (European Cooperation in Science and Technology). H.X. acknowledges the Spanish MINECO through the Severo Ochoa Centers of Excellence Program under Grant SEV-2013-0295 for the postdoctoral contract.

In literature, varying and sometimes conflicting effects of physicochemical properties of nanoparticles (NPs) are reported on their uptake and effects in organisms. To address this, small- and medium-sized (20 and 50 nm) silver nanoparticles (AgNPs) with specified different surface coating/charges were synthesized and used to systematically assess effects of NP-properties on their uptake and effects in vitro. Silver nanoparticles were fully characterized for charge and size distribution in both water and test media. Macrophage cells (RAW 264.7) were exposed to these AgNPs at different concentrations (0-200 µg/ml). Uptake dynamics, cell viability, induction of tumor necrosis factor (TNF)-α, ATP production, and reactive oxygen species (ROS) generation were assessed. Microscopic imaging of living exposed cells showed rapid uptake and subcellular cytoplasmic accumulation of AgNPs. Exposure to the tested AgNPs resulted in reduced overall viability. Influence of both size and surface coating (charge) was demonstrated, with the 20-nm-sized AgNPs and bovine serum albumin (BSA)-coated (negatively charged) AgNPs being slightly more toxic. On specific mechanisms of toxicity (TNF-α and ROS production) however, the AgNPs differed to a larger extent. The highest induction of TNF-α was found in cells exposed to the negatively charged AgNP_BSA, both sizes (80× higher than control). Reactive oxygen species induction was only significant with the 20 nm positively charged AgNP_Chit., This work was financially supported by NanoNextNL, a micro- and nanotechnology consortium of the Government of The Netherlands and 130 partners; funding was also received from Managing Risks of Nanoparticles, MARINA (EU-FP7, contract CP-FP 263215); and the Strategic Research Funds titled Novel technologies by the Ministry of Economic Affairs of The Netherlands. Synthesis and characterization of the AgNPs used in this study received support from the QualityNano Project (http://www.qualitynano.eu/) financed by the European Community Research Infrastructures under the FP7 Capacities Program (Grant Number INFRA-2010-262163).

While self-assembled molecular building blocks could lead to many next-generation functional organic nanomaterials, control over the thin-film morphologies to yield monolithic sub-5 nm patterns with 3D orientational control at macroscopic length scales remains a grand challenge. A series of photoresponsive hybrid oligo(dimethylsiloxane) liquid crystals that form periodic cylindrical nanostructures with periodicities between 3.8 and 5.1 nm is studied. The liquid crystals can be aligned in-plane by exposure to actinic linearly polarized light and out-of-plane by exposure to actinic unpolarized light. The photoalignment is most efficient when performed just under the clearing point of the liquid crystal, at which the cylindrical nanostructures are reoriented within minutes. These results allow the generation of highly ordered sub-5 nm patterns in thin films at macroscopic length scales, with control over the orientation in a noncontact fashion., This research was supported by the Dutch Technology Foundation STW, which is part of the Netherlands Organisation for Scientific Research (NWO), and which is partly funded by the Ministry of Economic Affairs. C.S.-S. thanks the Spanish MINECO projects MAT2011-27978-C02-02, SAF2014-54763-C2-2-R, Gobierno de Aragón, and FEDER (EU). P.L. is a Senior Research Associate from FRS-FNRS (Belgium). The X-ray diffractometer was financed by The Netherlands Organisation for Scientific Research (NWO).

et al., Physicochemical properties of nanoparticles influence their environmental fate and toxicity, and studies investigating this are vital for a holistic approach towards a comprehensive and adequate environmental risk assessment. In this study, we investigated the effects of size, surface coating (charge) of silver nanoparticles (AgNPs) – a most commonly-used nanoparticle-type, on the bioaccumulation in, and toxicity (survival, growth, cocoon production) to the earthworm Lumbricus rubellus. AgNPs were synthesized in three sizes: 20, 35 and 50 nm. Surface-coating with bovine serum albumin (AgNP_BSA), chitosan (AgNP_Chit), or polyvinylpyrrolidone (AgNP_PVP) produced negative, positive and neutral particles respectively. In a 28-day sub-chronic reproduction toxicity test, earthworms were exposed to these AgNPs in soil (0–250 mg Ag/kg soil DW). Earthworms were also exposed to AgNO3 at concentrations below known EC50. Total Ag tissue concentration indicated uptake by earthworms was generally highest for the AgNP_BSA especially at the lower exposure concentration ranges, and seems to reach a plateau level between 50 and 100 mg Ag/kg soil DW. Reproduction was impaired at high concentrations of all AgNPs tested, with AgNP_BSA particles being the most toxic. The EC50 for the 20 nm AgNP_BSA was 66.8 mg Ag/kg soil, with exposure to AgNP_PVP (neutral) > Chitosan (positive). Size had an influence on uptake and toxicity of the AgNP_PVP, but not for AgNP_BSA nor AgNP_Chit. This study provides essential information on the role of physicochemical properties of AgNPs in influencing uptake by a terrestrial organism L. rubellus under environmentally relevant conditions. It also provides evidence of the influence of surface coating (charge) and the limited effect of size in the range of 20–50 nm, in driving uptake and toxicity of the AgNPs tested., This work was financially supported by NanoNextNL, a micro- and nano-technology consortium of the Government of The Netherlands and 130 partners; funding was also received from Managing Risks of Nanoparticles, MARINA (EU-FP7, contract CP-FP 263215), and; the Strategic Research Funds titled Novel technologies by the Ministry of Economic Affairs of The Netherlands. Synthesis and characterization of the AgNPs used in this study received support from the QualityNano Project http://www.qualitynano.eu/which is financed by the European Community Research Infrastructures under the FP7 Capacities Programme (Grant No. INFRA-2010-262163).

4 pags., 5 figs., The emission from nanowires can couple to waveguide modes supported by the nanowire geometry, thus governing the far-field angular pattern. To investigate the geometry-induced coupling of the emission to waveguide modes, we acquire Fourier microscopy images of the photoluminescence of nanowires with diameters ranging from 143 to 208 nm. From the investigated diameter range, we conclude that a few nanometers difference in diameter can abruptly change the coupling of the emission to a specific mode. Moreover, we observe a diameter-dependent width of the Gaussian-shaped angular pattern in the far-field emission. This dependence is understood in terms of interference of the guided modes, which emit at the end facets of the nanowire. Our results are important for the design of quantum emitters, solid state lighting, and photovoltaic devices based on nanowires. VC 2016 AIP Publishing LLC, This research was supported by the Dutch technology foundation STW, which is part of the “Netherlands Organisation for Scientific Research (NWO),” and partially funded by the Dutch Ministry of Economic Affairs. This work was also part of the research program of the “Foundation for Fundamental Research on Matter (FOM),” which is financially supported by NWO. J.A.S.G. acknowledges the Spanish Ministerio de Economía y Competitividad for financial support through the Grant Nos. NANOPLASþ (FIS2012-31070) and LENSBEAM (FIS2015-69295-C3-2-P).