Synthesis and characterization of ZnO and Ag nanoparticle-loaded TiO2 nanotube composite layers intended for antibacterial coatings

• ZnO and/or Ag nanoparticle-loaded TiO2 nanotube composite layers were fabricated.
• Homogeneous surface distribution of ZnO and Ag nanoparticles was achieved.
• ZnO and/or Ag/TiO2 nanotube coatings may exhibit synergistic antibacterial activity.

In this work we have fabricated nanoporous oxide layers on Ti with the addition of Ag or ZnO nanoparticles in order to obtain functional coatings ensuring both biocompatibility and antibacterial properties. The morphological and chemical features of the composite coatings fabricated were studied with the aid of high-resolution scanning electron microscopy and surface analytical techniques such as Auger electron spectroscopy and X-ray photoelectron spectroscopy. Our results have shown that Ag and ZnO nanoparticles can be incorporated in a simple and economic manner, suitable for the fabrication of a bactericidal material. The amount of the nanoparticles is variable and depends on the deposition process conditions. The nanoparticles are distributed homogeneously at the top surface of the coating, however they exhibit in depth distribution gradient. This may be promising for maintaining a steady antibacterial effect.