Exploring the use of dye-sensitisation by visible-light as new approach to self-cleaning textiles

Photocatalytic degradation of organic contaminants by self-cleaning textiles is an efficient method to create green environment and minimise energy consumption. In this work, the concept of dye-sensitised self-cleaning textiles has been introduced by incorporating monolayers of meso-tetra(4-carboxyphenyl) porphyrin (TCPP) on the surface of titania-coated cotton against methylene blue. Different complexes of TCPP (M = 2H, Fe, Co, Zn, Cu) have been trialled and evaluated for photocatalytic activity and stability. Cotton fabrics coated with TCPP show superior photochemical activity as compared to TiO₂-coated fabrics under visible-light irradiation. The free base derivative availed the highest photocatalytic efficiency when compared to the metal complexes with CuFe > Co > Zn. In terms of stability, meso-tetra(4-car-boxyphenyl) porphyrinato copper(II) showed significant stabilisation under photocatalytic conditions when compared to the metal-free porphyrin and other metal complexes (Cu ≠Co > 2H > ZnFe). Porphyrins offer great potential in visible-light self-cleaning applications. Self-assembled monolayers of meso-tetra(4-carboxyphenyl) porphyrin (TCPP) and its metal complexes (M = Fe, Co, Zn, Cu) in combination with TiO₂ have been formed on cotton fabrics. The metal-free porphyrin showed the highest photocatalytic efficiency as compared to the metal complexes (MTCPP) under visible-light irradiation. In terms of reproducibility, Cu(II)TCCP showed significant stability under visible-light irradiation. © 2014 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.