Selective hydrogenation of arenes to cyclohexanes in water catalyzed by chitin-supported ruthenium nanoparticles

The selective hydrogenation of arenes to cyclohexanes is promoted by Ru/chitin under aqueous conditions without the loss of C–O/C–N linkages.This work was financially supported by the Ichihara International Scholarship Foundation (to H. N.), the Institute for Quantum Chemical Exploration (to H. N.), MEXT (Japan) through its program “Integrated Research on Chemical Synthesis” (to H. N.) and the Royal Society through its International Exchange Scheme (to A. E. H. W. and H. N.). K. B. and B. R. K. thank the UK EPSRC (EP/J500380/1). Y. M. and A. M. acknowledge the IGER program at NU. We thank Professors R. Noyori (NU), S. Saito (NU) and K. Shimizu (Hokkaido U) for their helpful comments.This is the final version of the article. It first appeared from Royal Society of Chemistry at http://dx.doi.org/10.1039/C6CY00899B

Targeting low-cost type-II heterostructures: Synthesis, structure and photoreactivity

One design strategy by which to iterate the photocatalytic efficiency of semiconducting nanomaterials for harvesting solar energy involves the synthesis of type-II heterostructured materials. In this article, a straightforward, facile and environmentally benign route to heterostructures in which SnO₂ nanospheres are capped by PbS nanocubes is reported. It offers to address current limitations to photocatalytic efficiency brought about by electron-hole recombination and narrow photoresponsive ranges in many existing systems. PbS nanocubes are grown in the presence of preformed SnO₂ nanospheres by functionalizing the surface of the latter using cetyltrimethylammonium bromide (CTAB). Heterostructure formation is confirmed by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area analysis, and transmission electron microscopy (TEM) analysis. Rietveld refinement has been exploited to simultaneously elucidate the atomic and microstructures of these materials, allowing the quantitative determination of particle structure and stability. The combination of narrow band-gap semiconductor (PbS) and wide band-gap semiconductor (SnO₂) endows the heterostructured nanomaterial with potential as a photocatalyst and, in the degradation of Rhodamine B (RhB) dye under solar simulation, it showed superior photocatalytic activity to that of its separate SnO₂ and PbS components. A strong type-II interaction is demonstrated by the heterostructure and a charge separation mechanism has been utilized to clarify this behaviour.A. K. acknowledges support from the Royal Society's Newton International Fellowship scheme (NF130808). B. R. K. thanks the UK EPSRC for financial support (EP/J500380/1)

Hydration of nitriles to amides by a chitin-supported ruthenium catalyst

Chitin-supported ruthenium (Ru/chitin) promotes the hydration of nitriles to carboxamides under aqueous conditions.This work was partly supported by grant from Yoshida Foundation for Science and Technology (to H.N.) and the program “Integrated Research on Chemical Synthesis”, MEXT, Japan (to H.N.). A.M. acknowledges a Grant-in-Aid for JSPS fellows (25 4305) and IGER program at NU. B.R.K. thanks the UK EPSRC for financial support (EP/J500380/1) and A.E.H.W. thanks the GB Sasakawa Foundation for travel grant 4388.This is the final published version. It first appeared at http://pubs.rsc.org/en/Content/ArticleLanding/2015/RA/c4ra15682j#!divAbstract

Island-type growth of Au-Pt heterodimers: direct visualization of misfit dislocations and strain-relief mechanisms

Structural and analytical characterization related to the formation mechanism of Au–Pt heterodimers from polyhedral Pt nanocrystals is reported.This work has received funding from the European Union within the 7th Framework Programme under Project Al-NanoFunc CTREGPOT- 2011-1-285895 and Grant Agreement no.312483 (ESTEEM2). We acknowledge financial support from the CSIC (PIE 201460E018), the Spanish Ministry MINECO (project CTQ2012- 32519), Junta de Andalucía (FEDER PE2009-FQM-4554, TEP217 and PE2012-TEP-862) and the Graz Centre for Electron Microscopy (ZFE Graz). Thanks go also to the UK Engineering and Physical Sciences Research Council for a studentship for B. R. Knappett (EP/J500380/1).This is the final version of the article. It first appeared from RSC via http://dx.doi.org/10.1039/C5RA09808