Nanotechnology Volume 28, No. 6, January 2017

S. Schlicht, A. Kireev, E. Grachova, S. Tunik, A. Manshina, J. Bachmann

A model electrode of well-defined geometry prepared by direct laser-induced decoration of nanoporous templates with Au–Ag@C nanoparticles

Nanotechnology Volume 28, No. 6, January 2017

DOI: 10.1088/1361-6528/aa536a

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We present an original type of model electrode system consisting of bimetallic Au–Ag nanoparticles embedded in an amorphous carbon matrix with an extremely well-defined geometry of parallel, straight, cylindrical macropores. The samples are prepared in one step by direct laser deposition of the metal/carbon composite onto the inner walls of a porous ‘anodic’ alumina matrix serving as a template. The coating is homogeneous from top to bottom of the pores, and the amount of material deposited can be tuned by the duration of the deposition procedure. As a test system, we demonstrate that a bimetallic Ag–Au@C system is catalytically active for the electrochemical oxidation of glucose in alkaline solution, the anodic reaction of a direct glucose fuel cell. Furthermore, the electrocatalytic current density increases with the amount of Ag–Au@C NPs deposited, up to a point at which the pores are clogged with it. This type of model system allows for the systematic study of geometric effects in fuel cell electrodes. It can be generalized to a number of different nanoparticle compositions, and thereby, to various electrocatalytic reactions.

 

Opt Quant Electron (2017) 49:50

E.I. Ageev,  Y.M. Andreeva,  P.N. Brunkov, Y. Y. Karlagina,  G. V. Odintsova, D.V. Pankin, S.I. Pavlov, V.V. Romanov, R.M. Yatsuk

«Influence of light incident angle on reflectance spectra of metals processed by color laser marking technology»

Opt Quant Electron (2017) 49:50

DOI 10.1007/s11082-016-0876-4

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A comparison of oxide films formed on the stainless steel surface during laser and furnace heating is presented. Obtained samples were examined by optical and scanning electron microscopy. In order to characterize the optical properties, reflection spectra within the wavelength range 190–900 nm were measured with a spectrophotometer equipped with the integrating sphere for incidence angles from 0 to 60. The topology of obtained oxide films was characterized by scanning probe microscopy. Due to light interference in produced films, the coloration of treated area is observed. It was found that there is no change in the characteristic appearance of reflectance spectra at different light incidence angles, but a blue-shift occurs especially for the case of laser-induced films, which results in a visible change of surface color. This effect is associated with an interference character of originating color and features of surface relief under an oxide film.

 

Director of the RC OLMIV Alexey Viktorovich Kurochkin as a member of the official delegation from the Science Park of St. Petersburg State University took part in the largest congress and exhibition event of the North-West, St. Petersburg International Innovation Forum.

The University presented a stand with information on the scientific infrastructure, as well as research and development being conducted at St. Petersburg State University at the forum. Within the framework of the forum, representatives of government bodies, business structures, as well as high school experts discussed topical issues of introducing innovations in production.

 

The Raman spectrometer Horiba Jobin-Yvon LabRam HR800 serves to obtain Raman scattering spectra for the identification of the studied substances in a solid, liquid or gaseous state, phase diagnostics of inclusions in minerals, evaluation of the degree of crystallinity of a substance, for studies of the transformation of substances as a result of chemical, electrochemical reactions, research changes in biological tissues. The presence of a built-in microscope allows to obtain information from micrometer objects. Confocal optical scheme allows to achieve the maximum degree of detail while maintaining a high speed of image acquisition.

Employees of the RC OLMIV have commissioned a spectrophotometer Shimadzu UV-3600 for operation in the UV, visible and near-IR spectral range. The device is equipped with an integrating sphere for measuring the scattering and extinction spectra. For the measurements it is necessary to submit an application (http://client.researchpark.spbu.ru).