This study demonstrates a low-pressure coating (LPC) technique for the deposition of titania films. In this process, compressed air is used to accelerate angular titania feedstock into a substrate such as stainless steel, producing a photoactive surface consisting of embedded titania particles. The method is relatively inexpensive, requiring only the basic materials and an air supply. A range of LPC titania coatings were produced, varying nozzle stand-off distance, air pressure, and substrate exposure time. Samples are characterized via SEM and EDX analysis, photocurrent measurements, and NOX removal testing.

This study assesses the viability of three suspension spray processes for producing photocatalytic TiO2. In the experiments, flame, plasma, and HVOF torches were used to spray TiO2 suspensions onto stainless steel substrates, varying process parameters in order to gauge their effect on phase composition, crystal size and, in turn, photoactivity. The TiO2 samples were characterized by means of XRD, SEM, and UV-Vis analysis and photocatalytic hydrogen-production testing. Suspension flame spraying proved to be the most effective method, producing phase-controlled nanostructured titania 32% more photoactive than the SPS samples and up to five times more active than analogous coatings produced by CVD.

In this study, suspension HVOF spraying is used to deposit TiO2 nanoparticles on 304 stainless steel substrates. Spray parameters are varied, including spray distance and number of passes, to determine their effect on friction and wear properties as well as surface topography, microstructure, and phase composition. The spray parameters used, the microstructures observed, and the wear mechanisms of the nanostructured TiO2 coatings are described in the paper.