Structural Investigations of Ni Deposited on Porous Anodic Alumina Matrices.
R.G. Valeev, V.V. Stashkova, A.I. Chukavin, V.V. Kriventsov, N.A. Mezentsev. Structural investigations of Ni deposited on porous anodic alumina matrices. The International Conference "Synchrotron and Free electron laser Radiation: generation and application" (SFR-2016) – Novosibirsk, 04 - 07 Jul 2016.
Iron, nickel, cobalt, platinum and other 3d and platinum group metals, their alloys and intermetallic compounds are traditionally used as cathodes in electrolytic hydrogen evolution reaction (HER) in aqueous acid and alkaline solutions. Nickel stands out among them because of the fact that, having high corrosion resistance in acidic and alkaline media compared with platinum group metals, it has a low cost and so is widely used. It should be noted that the efficiency of HER depends on the area of contact of the cathode material with the electrolyte, so there is an increased interest in literature to the nickel based materials having a developed surface due to the formation of metal nanoparticles with different morphology . This is due to the large contribution of surface electronic states of the metal in HER. It is also strongly affected by the structural-phase state and local atomic and electronic structure causing nickel chemical activity. The aim of this work is to develop methods of magnetron sputtering nickel on high surface area membranes of a porous anodic alumina morphology and to study the structural-phase state, local atomic and electronic structures of the samples, depending on the parameters of the Al2O3 porous structure (the pore diameter, the distance between the individual pores). As a result of a complex study (XAFS, XRD, SEM), the state and local structure of samples obtained by few ways were revealed. The geometrical characteristics of Ni nanostructures, their crystalline and local atomic structure were studied. The local atomic structure parameters were compared to those revelaed in investigations of the nickel film obtained on smooth Al2O3 surface. All possible structural models were discussed in detail.