Dielectric Barrier Discharge Plasma Processing and Sr-Doped ZnO/CNT Photocatalyst Decoration of Cotton Fabrics for Self-Cleaning Application

Abstract

Nonthermal plasma processing is a chemical-free and environmentally friendly technique to enhance the self-cleaning activity of nanoparticle-coated cotton fabrics. In this research, Sr-doped ZnO/ carbon nanotube (CNT) photocatalysts, namely, S 10 ZC 2 , S 15 ZC 2 , and S 20 ZC 2 with different Sr doping concentrations, were synthesized using the sol−gel method and coated on plasma-functionalized fabric to perform the self-cleaning tests. The fabrics were treated with dielectric barrier discharge plasma in an open environment for 3 min to achieve a stable coating of nanoparticles. The energy band gap of the photocatalyst decreased with an increase in the level of Sr doping. The band gap of S 10 ZC 2 , S 15 ZC 2 , and S 20 ZC 2 photocatalysts was estimated to be 2.85, 2.78, and 2.5 eV, respectively. The hexagonal wurtzite structure of ZnO was observed on the fabric surface composited with CNTs and Sr. The S 20 ZC 2 photocatalyst showed better homogeneity and photocatalytic response on the fabric when compared with S 10 ZC 2 -and S 15 ZC 2 -coated fabrics. The S 20 ZC 2 photocatalyst showed 89% dye degradation efficiency after 4 h of light exposure in methylene blue solution, followed by S 15 ZC 2 (84%) and S 10 ZC 2 (80%) photocatalysts.