Preparation, characterization, and application of TiO-patterned polyimide film as a photocatalyst for oxidation of organic contaminants.

Photocatalytically active TiO-patterned polyimide (PI) films (PI-TiO) were fabricated using thermal transfer patterning (TTP). When subjected to hot pressing, the TiO nanoparticles electrosprayed on steel mesh templates were successfully transferred and formed checker plate patterns on PI film. FE-SEM studies confirmed that pressing at 350°C and 100MPa was optimum for obtaining patterns with uniform TiO coverage. When the quantity of TiO on the template increased, the amount of it immobilized on PI film also increased from 0.3245 to 1.2378mg per 25cm. XPS studies confirmed the presence TiO on the patterns, and indicated the formation of carboxylic acid and amide groups on the PI surface during TTP. When tested under UVA irradiation, PI-TiO with 1.2378mg/25cm TiO loading exhibited the highest photocatalytic performance for methylene blue (10μM) degradation, with a rate constant of 0.0225min and stable photocatalytic efficacy for 25 cycles of reuse. The PI-TiO was also successfully used to degrade amoxicillin, atrazine, and 4-chlorophenol. During photocatalysis, the toxicity of 4-chlorophenol against Vibrio fischeri and the antibiotic activity of amoxicillin against Escherichia coli were decreased. Overall, TTP was found to be a potentially scalable method for fabricating robust immobilized TiO photocatalyst.