Format

Send to

Choose Destination
Sci Rep. 2019 Feb 13;9(1):1883. doi: 10.1038/s41598-018-38291-y.

Nanostructured TiO2 anatase-rutile-carbon solid coating with visible light antimicrobial activity.

Author information

1
Advanced Energy and Material Systems Laboratory, Department of Mechanical Engineering, University of Canterbury, Christchurch, 8041, New Zealand. susan.krumdieck@canterbury.ac.nz.
2
Univ. Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering), SIMAP, F-38000, Grenoble, France.
3
Advanced Energy and Material Systems Laboratory, Department of Mechanical Engineering, University of Canterbury, Christchurch, 8041, New Zealand.
4
Department of Chemistry, University of Canterbury, Christchurch, 8041, New Zealand.
5
School of Biological Sciences, University of Canterbury, Christchurch, 8041, New Zealand.

Abstract

TiO2 photocatalyst is of interest for antimicrobial coatings on hospital touch-surfaces. Recent research has focused on visible spectrum enhancement of photocatalytic activity. Here, we report TiO2 with a high degree of nanostructure, deposited on stainless steel as a solid layer more than 10 μm thick by pulsed-pressure-MOCVD. The TiO2 coating exhibits a rarely-reported microstructure comprising anatase and rutile in a composite with amorphous carbon. Columnar anatase single crystals are segmented into 15-20 nm thick plates, resulting in a mille-feuilles nanostructure. Polycrystalline rutile columns exhibit dendrite generation resembling pine tree strobili. We propose that high growth rate and co-deposition of carbon contribute to formation of the unique nanostructures. High vapor flux produces step-edge instabilities in the TiO2, and solid carbon preferentially co-deposits on certain high energy facets. The equivalent effective surface area of the nanostructured coating is estimated to be 100 times higher than standard TiO2 coatings and powders. The coatings prepared on stainless steel showed greater than 3-log reduction in viable E coli after 4 hours visible light exposure. The pp-MOCVD approach could represent an up-scalable manufacturing route for supported catalysts of functional nanostructured materials without having to make nanoparticles.

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center