Preparation of Ultrafine Fibrous Membrane with TiO2/Bi2SiO5 Photocatalyst on Eggshell and its Degradation of Organic Dye under Visible Light

Abstract Due to the wide energy gap as well as short life of TiO2 and its photocatalytic active only under ultraviolet light, its application is greatly limited. TiO2 can form a heterojunction with other semiconductors to enhance its photocatalytic ability under visible light. In this study, a TiO2/Bi2SiO5 photocatalyst with n-n heterojunction is successfully synthesized by sol-gel method and hydrothermal method. Eggshell waste has long been used as fertilizer for planting plants or food additives for livestock, or as an adsorbent in metal ions and organic dyes. Using eggshell as a carrier of photocatalyst reduces its cracking of the substrate. The photocatalyst is deposited on eggshell powder by solid state dispersion (SSD). It is analyzed for the adsorption and degradation of methylene blue by various compositions of the photocatalysts and eggshell powder under visible light. The results show that the ratio of TiO2/Bi2SiO5: eggshell powder at 1:1 has the best removal ability. To facilitate the recovery of the photocatalyst from the aqueous solution, we use electrostatic spraying and electrospinning techniques to prepare nylon 6,6 nanofiber membranes with various composite photocatalyst (TiO2/Bi2SiO5/Eggshell/Nylon 6,6 NFM), the nanofiber membrane degraded 98% of methylene blue after 30 minutes of dark adsorption and 1 hour of visible light irradiation.