Improvement of antibacterial activity of hydrothermal treated TC4 substrate through an in-situ grown TiO2/g-C3N4 Z-scheme heterojunction film

In-situ growth of a TiO2/g-C3N4 film with Z-scheme heterojunction structure on the hydrothermally treated titanium alloy via a calcination approach was firstly demonstrated in this work. Compared with the hydrothermally treated substrates, the as-prepared samples showed good hydrophilicity and osteoblast-like cell proliferation, evidencing their potential for improving the biocompatibility and osteogenesis of titanium alloy. Subsequently, more than 65% of E. coli was reduced on the surface of TiO2-g-C3N4 film under natural sunlight, indicating an enhanced antibacterial activity. The noticeably improvement of the antibacterial performance was ascertained mainly due to the presence of Z-scheme heterojunction between TiO2 and g-C3N4. Such structure could not only improve the separation and transfer of photogenerated carriers, but also increase the number of photogenerated electrons, thus enhancing the yielding of reactive oxygen species (ROS) to kill bacteria. (C) 2020 Elsevier B.V. All rights reserved.