Role of cellulose fibers in enhancing photosensitized oxidation of basic green 1 with massive dyeing auxiliaries

Abstract

Due to their abundance, high natural affinity to various reactants, cellulose fibers (CFs) are promising catalysts supports for real wastewater treatment. Herein, a new visible-light-responsive cellulose fibers-supported zinc tetra(2,4-dichloro-1,3,5-triazine)aminophthalocyanine (denoted as Zn-TDTAPc-F) catalyst system was fabricated for removing dyes from aqueous solution in the presence of massive dyeing auxiliaries. In contrast to most traditional radical-dominated catalytic systems in which dyeing auxiliaries always play negative roles, the photosensitized oxidation of BG1 over Zn-TDTAPc-F catalyst has been obviously enhanced with auxiliaries such as NaCl, urea and isopropanol, most likely owing to the “primitive” outstanding properties of CFs such as their controllable surface charge (zeta potential), good swelling properties and intermolecular hydrogen bonding structures as well as the participation of non-radical singlet oxygen as the primary oxidant. On the basis of our experimental observations, a possible photosensitized oxidation mechanism including the photogeneration of singlet oxygen and the fundamental roles of CFs have been discussed in detail. These findings provide a new approach for removing highly hazardous target pollutants in actual wastewater with massive organic and inorganic substances, and further set a good example for the design and optimization of the catalyst via well controlling the supports.