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MXenes, a family of two-dimensional (2D) transition metal carbides, have been discovered as exciting candidates for various energy storage and conversion applications, including green hydrogen production by water splitting. Today, these materials mostly remain interesting objects for in-depth fundamental studies and scientific curiosity due to issues related to their preparation and environmental stability, limiting potential industrial applications. This work proposes a simple and inexpensive concept of composite electrodes composed of molybdenum- and titanium-containing MAX phases and MXene as functional materials. The concept is based on the modification of the initial MAX phase by the addition of metallic Ni, tuning Al- and carbon content and synthesis conditions, followed by fluoride-free etching under alkaline conditions. The proposed methodology allows producing a composite electrode with a well-developed 3D porous MAX phase-based structure acting as a support for electrocatalytic species, including MXene, and possessing good mechanical integrity. Electrochemical tests have shown a high electrochemical activity of such electrodes towards the hydrogen evolution reaction (HER), combined with a relatively high areal capacitance (up to 10 F cm -2 )., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Gold-metallic nanofibrils were prepared from three different iso-apoferritin (APO) proteins with different Light/Heavy (L/H) subunit ratios (from 0% up to 100% L-subunits). We show that APO protein fibrils have the ability to in situ nucleate and grow gold nanoparticles (AuNPs) simultaneously assembled on opposite strands of the fibrils, forming hybrid inorganic-organic metallic nanowires. The AuNPs are arranged following the pitch of the helical APO protein fiber. The mean size of the AuNPs was similar in the three different APO protein fibrils studied in this work. The AuNPs retained their optical properties in these hybrid systems. Conductivity measurements showed ohmic behavior like that of a continuous metallic structure., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

New insights into the chemical and structural features of iron or titanium-doped KxMnO2 hollandites are reported. Neutron diffraction and atomically resolved transmission electron microscopy elucidate the localization of the dopant cations that could be one of the key factors governing the functional activity of these nanomaterials.

Pt impregnated on a Sn-beta catalyst results in a very promising catalyst for the selective hydrogenation of α,β-unsaturated aldehydes, compared to the PtSn co-impregnated beta catalysts. Framework tin ions in the Sn-beta sample stabilize the nucleation of platinum nanoparticles inside the zeolite channel. These Pt(0)-Sn(4+) sites, which are only observed in the Pt/Sn-beta catalyst, have been shown to strongly activate the carbonyl group enhancing the hydrogenation rate of the C=O bond.

Nano-structural and nano-analytical studies show that the dramatic difference in CO oxidation activity observed between two Au/Ce0.50Tb0.12Zr0.38O2-x samples prepared by deposition-precipitation with urea and further activated under oxidising or reducing conditions is due to the poisoning effect of a very thin layer of carbon grown on the pre-reduced catalyst.

A mesoporous TiO(2)-SiO(2) nanocomposite photocatalyst has been prepared from TiO(2) nanoparticles and ethoxysilane oligomers in the presence of a non-ionic surfactant (n-octylamine). The 2D and 3D structure properties of the resulting nanomaterial are described. The use of 3D techniques, particularly HAADF-STEM electron tomography, together with 3D reconstructions and atomic force microscopy, provides insight into the fine structure of these materials. We find that n-octylamine creates a mesoporous silica structure in which titania nanoparticles are embedded, and that some of the titania is retained on the outer surface of the material. Rapid photodegradation of methylene blue dye is facilitated, due to the synergistic effect of: (1) its adsorption into the composite mesoporous structure, and (2) its photodegradation by the superficial TiO(2).

In-situ Atomic Resolution Transmission Electron Microscopy studies carried out on a Rh/Ce0.8Pr0.2O(2-x) catalyst, under hydrogen in the temperature range 298-1223 K, show the occurrence of consecutive reduction of Pr4+ and Ce4+ ions, and the formation of an oxygen-deficient Ln16O30 (Ln: Ce, Pr) ordered phase.