Poly(vinyl alcohol)-tragacanth gum/Titania bio-nanocomposite film for photodecomposition of malachite green

Concerned about the contamination as a consequence of untreated wastewater worldwide, nanomaterials have been utilized for purification. Nevertheless, their separation from water is difficult after the treatment. Herein, Titania nanomaterials were embedded in a poly(vinyl alcohol)-tragacanth gum (PVA-TG) matrix, due to easy separation. The polymer matrix was cross-linked by a green agent of citric acid, and the physicochemical properties of PVA-TG/Titania bio-nanocomposite (bio-NC) films were characterized, which displayed a high swelling ratio in the water because of the addition of TG. Further, Titania nanomaterials illustrated a cube-like shape in the PVA-TG/Titania bio-NC film confirming the complete dispersion. Afterward, the photodecomposition of malachite green (MG) over this bio-NC film was studied and optimized under ultraviolet (UV) irradiation. Scavenger agents determined that the electron was produced more than other radical agents. Ultimately, the photodegradation process of MG over bio-NC films was suggested by the hydroxyl addition, singlet oxygen, and UV irradiation transformation pathways.