Photocatalytic Efficiency of Metallo Phthalocyanine Sensitized TiO2 (MPc/TiO2) Nanocomposites for Cr(VI) and Antibiotic Amoxicillin

Abstract

Dye sensitization on semiconductor catalyst TiO2 was performed with four different metallophthalocyanine (MPc) derivates (M: Zn, Cu, Co, and Si) using a modified sol-gel method. MPc derivatives were loaded on TiO2 at 1% mass ratio aiming to increase its photocatalytic action and to shift the light absorption to higher UV region (365 nm). Non-ionic surfactant Triton X-100 (TX-100) was used to obtain a homogenous and mesa pore catalyst structure. The prepared catalysts were characterized by FT-IR, XRD, and SEM to determine the crystal and surface structural properties of nanocomposites. The nanocomposites were used for photocatalytic removal and degradation of Cr(VI) and amoxicillin (AMX) as model pollutants. Photocatalytic reduction capacities of the catalysts were tested for Cr(VI) (10 mg/L) and AMX (20 mg/L) aqueous solutions. ZnPc-TiO2 catalyst was successful for Cr(VI) photoreduction since all Cr(VI) ions in the solution were successfully removed. Presence of TX-100 in the sol-gel synthesis of ZnPc-TiO2 had a positive effect by increasing the Cr(VI) removal rate to 97.93% after 150 min exposure period. Prepared catalysts were also tested for photodegradation of AMX, applying similar procedures. In general, all catalysts exhibited low degradation rates under the studied condition but more effective with 254 nm UV light (50.38%). Neither surface modification with TX-100 nor MPc sensitization provided significant degradation of AMX.