Catalytic Activity of Ni Nanotubes Covered with Nanostructured Gold

Abstract

Ni nanotubes (NTs) were produced by the template method in the pores of ion-track membranes and then were successfully functionalized with gold nanoparticles (Ni@Au NTs) using electroless wet-chemical deposition with the aim to demonstrate their high catalytic activity. The fab-ricated NTs were characterized using a variety of techniques in order to determine their morphology and dimensions, crystalline structure, and magnetic properties. The morphology of Au coating de-pended on the concentration of gold chloride aqueous solution used for Au deposition. The catalytic activity was evaluated by a model reaction of the reduction of 4-nitrophenol by borohydride ions in the presence of Ni and Ni@Au NTs. The reaction was monitored spectrophotometrically in real time by detecting the decrease in the absorption peaks. It was found that gold coating with needle-like structure formed at a higher Au-ions concentration had the strongest catalytic effect, while bare Ni NTs had little effect. The presence of a magnetic core allowed the extraction of the catalyst with the help of a magnetic field for reusable applications. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The work was carried out with the support of the Ministry of Science and Higher Education of the Russian Federation in the framework of the State Task (project code 0718-2020-0037)