Titania Solid Thin Films Deposited by pp‐MOCVD Exhibiting Visible Light Photocatalytic Activity. Issue 2 (11th December 2017)

• Record Type: Journal Article
• Authors: Krumdieck, Susan; Gorthy, Rukmini; Land, Johann G.; Gardecka, Aleksandra J.; Polson, Matthew I. J.; Boichot, Raphael; Bishop, Catherine M.; Kennedy, John V.
• Is Part Of: Physica status solidi. Volume 215:Issue 2(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-12-11
• Subjects: photocatalytic activity -- pp‐MOCVD -- pyrolytic carbon -- thin solid films -- TiO2 -- visible light; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201700578
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : The crisis of hospital‐acquired infections is driving intense interest in surface coatings that can inhibit colonization and reduce spread of pathogens to vulnerable patients. Widespread use of antibiotics and antimicrobial silver and copper has been demonstrated to trigger evolution of resistant strains of bacteria. The self‐cleaning properties of TiO2 could be a breakthrough for fighting HAI outbreaks if the photocatalytic activity (PCA) can be shifted to the spectrum of indoor light, and if a robust coating could be manufactured on hospital touch surfaces. MOCVD using titanium tetraisopropoxide (TTIP) is currently the standard method for applying self‐cleaning TiO2 to industrial glass. In this study, pulsed‐pressure MOCVD (pp‐MOCVD) was used to produce a solid coating composed of columnar microstructure anatase phase TiO2 with 200 nm diameter. This microstructure has enhanced active surface area and co‐deposited amorphous carbon on the crystal surfaces. The microstructure and carbon content were studied as a function of deposition temperature, and the new TiO2 coating was demonstrated to exhibit significant PCA under standard indoor lighting. Abstract : Titania‐carbon solid thin films are synthesized by pulsed pressure metal organic chemical vapor deposition. Increasing substrate temperature results in significant changes in both structure and composition of the film. The high temperature coatings are a remarkable black color, and exhibit significant visible light photocatalytic activity. The proposed mechanisms for PCA‐Vis are a thin pyrolytic carbon coating on crystal surfaces in the porous microstructure which has enhanced active surface area.