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We describe the preparation of a tungsten pillar nanoimprint stamp without the use of lithography and etching techniques. Structures with heights of 15 nm were prepared on the basis of self-ordered porous alumina templates and this was followed by DC sputtering of tungsten. The stamp was successfully used to prepare an aluminium surface to obtain highly ordered porous anodic alumina films after a single anodization step. The preparation efficiency for highly ordered porous alumina was dramatically improved as compared to the more conventional two-step anodization–strip-anodization method, as a sacrificial layer with a thickness of a few hundred micrometres was not required. In addition, by fractal calculations, we have evaluated the degree of ordering of the asperities on the nanoimprint master stamp. [ABSTRACT FROM AUTHOR]

Titanium oxide (TiO2) nanowires were prepared for an electrolytic capacitor application by the automatic dipping technique using a porous alumina template. The automatic dipping technique allows us to exactly control the dipping rate so that we can obtain homogenous infiltration of nanowires in the porous alumina membrane, even though the solution is very acidic. From the TEM, SEM and XRD measurements, we confirmed that anatase phase TiO2 nanowires are highly infiltrated into the porous alumina template. In addition, the electrostatic capacitance of nanowires was measured and compared with a theoretical calculation using an effective thickness (δe). We found that the effective thickness corresponds to the mean radius of nanowires and the experimental measurements were in good agreement with the calculations. [ABSTRACT FROM AUTHOR]

We describe a novel procedure to fabricate WO3@surface-mounted metal–organic framework (SURMOF) hybrid materials by electrodeposition of WO3 nanoparticles into HKUST-1, also termed Cu3(BTC)2 SURMOFs. These materials have been characterized using x-ray diffraction, time-of-flight secondary ion mass spectrometry, scanning electron microscopy, x-ray photoelectron spectroscopy as well as linear sweep voltammetry. The WO3 semiconductor/SURMOF heterostructures were further tested as hybrid electrodes in their performance for hydrogen evolution reaction from water. [ABSTRACT FROM AUTHOR]

Without using any additives, cuprous oxide (Cu2O) nanoparticles with a size of less than 20 nm that are hexagonally arrayed on a substrate are prepared by electrochemical methods based on the preferential nucleation of seeds on a nanostructured substrate. The nanosized Cu2O particles develop to become uniform microparticles of Cu2O. We found that the nanostructured substrate leads to the lowering of the overpotential for the nucleation of Cu2O particles and narrows the size distribution of the particles, compared to a polished substrate. [ABSTRACT FROM AUTHOR]