A method of pore fabrication in the walls of carbon nanotubes has been developed, leading to porous nanotubes that have been filled with catalysts and utilized in liquid- and gas-phase reactions. Chromium oxide nanoparticles have been utilized as highly effective etchants of carbon nanotube sidewalls. Tuning the thermal profile and loading of this nanoscale oxidant, both of which influence the localized oxidation of the carbon, have allowed the controlled formation of defects and holes with openings of 40–60 nm, penetrating through several layers of the graphitic carbon nanotube sidewall, resulting in templated nanopore propagation. The porous carbon nanotubes have been demonstrated as catalytic nanoreactors, effectively stabilizing catalytic nanoparticles against agglomeration and modulating the reaction environment around active centers. CO 2 sorption on ruthenium nanoparticles (RuNPs) inside nanoreactors led to distinctive surface-bound intermediates (such as carbonate species), compared to RuNPs on amorphous carbon. Introducing pores in nanoreactors modulates the strength of absorption of these intermediates, as they bond more strongly on RuNPs in porous nanoreactors as compared to the nanoreactors without pores. In the liquid-phase hydrosilylation of phenylacetylene, the confinement of Rh 4 (CO) 12 catalyst centers within the porous nanoreactors changes the distribution of the products relative to those observed in the absence of the additional pores. These changes have been attributed to the enhanced local concentration of phenylacetylene and the environment in which the catalytic centers reside within the porous carbon host.

The synthesis of ultrathin rhenium disulfide (ReS2) nanoribbons within single-walled carbon nanotubes (SWNTs) has been established. Dirhenium decacarbonyl complex is encapsulated into the SWNTs to provide a source of confined rhenium atoms, which readily react with iodine to form discrete nm-sized clusters of rhenium iodide [Re6I14]2− embedded in the nanotubes. The final step of the synthesis is accomplished by admitting hydrogen sulfide gas into nano test tubes, yielding twisted nanoribbons of rhenium disulfide encapsulated in carbon nanotubes, ReS2@SWNTs. The width, structure, and composition of rhenium disulfide nanoribbons are strictly controlled by the extreme confinement of the host-SWNT. A holistic analytical approach combining complementary imaging and analysis methods is used at each synthetic step to elucidate the structure and composition of the guest material and reveal the role of the SWNT contributing towards the electronic interactions with encapsulated inorganic structures. As ReS2 nanoribbons are expected to retain the electronic properties of the bulk material, such as direct bandgap, the low dimensional form of this material can be of interest for use in nanoscale electronic devices.

The preparation of 2D stacked layers that combine flakes of different nature, gives rise to countless number of heterostructures where new band alignments, defined at the interfaces, control the electronic properties of the system. Among the large family of 2D/2D heterostructures, the one formed by the combination of the most common semiconducting transition metal dichalcogenides WS2/MoS2, has awaken great interest due to its photovoltaic and photoelectrochemical properties. Solution as well as dry physical methods have been developed to optimize the synthesis of these heterostructures. Here a suspension of negatively charged MoS2 flakes is mixed with a methanolic solution of a cationic W3S4-core cluster, giving rise to a homogeneous distribution of the clusters over the layers. In a second step, a calcination under N2 of this molecular/2D heterostructure leads to the formation of clean WS2/MoS2 heterostructures where the photoluminescence of both counterparts is quenched, proving an efficient interlayer coupling. Thus, this chemical method combines the advantages of a solution approach (simple, scalable and low-cost) with the good quality interfaces reached by using more complicated traditional physical methods.

The preparation of 2D stacked layers combining flakes of different nature gives rise to countless numbers of heterostructures where new band alignments, defined at the interfaces, control the electronic properties of the system. Among the large family of 2D/2D heterostructures, the one formed by the combination of the most common semiconducting transition metal dichalcogenides, WS 2 /MoS 2 ,h as awakened great interest owing to its photovoltaic and photoelectrochemical properties.S olution as well as dry physical methods have been developedt oo ptimizet he synthesis of these heterostructures. Here, as uspension of negatively chargedM oS 2 flakes is mixed with am ethanolic solution of ac ationic W 3 S 4 -core cluster,g iving rise to ah omogeneous distribution of the clusters over the layers.I nasecond step, ac alcination of this molecular/2D heterostructure under N 2 leads to the formation of cleanW S 2 /MoS 2 heterostructures, where the photoluminescence of both counterparts is quenched, proving an efficient interlayer coupling. Thus,t his chemicalm ethod combines the advantages of as olution approach (simple, scalable, and low-cost) with the good quality interfaces reached by using more complicated traditional physicalmethods.[a] M. Morant-Giner,I.B rotons-Alcµzar, Dr.A.A lberola,D r. S. Tatay, Scheme1.Pictorial representationo fW S 2 /MoS 2 synthesis:( i) synthesiso fcluster@MoS 2 ;(ii)calcination of cluster@MoS 2 to give rise to the final heterostructure formed by MoS 2 layersi nb etween WS 2 flakes( WS 2 /MoS 2 ).

In this work, we demonstrate that the synergistic effect of PdAu nanoparticles (NPs) in hydrogenation reactions is not only related to high activity but also to their stability when compared...