Synthesis of tetracarboxy phthalocyanines modified TiO2 nanocomposite photocatalysts and investigation of photocatalytic decomposition of organic pollutant methylene blue under visible light

Abstract

The current work reports on the synthesis and characterization of peripherally tetra -4- carboxyethylenephenoxy substituted Zn(II) ( 4 ), Co(II) ( 5 ), Cu(II) ( 6 ) and TiO(IV) ( 7 ) phthalocyanine complexes and phthalocyanines ( 4 -7)-TiO2 photocatalysts consisting of pure TiO2 and the phthalcyanine complexes. The prepared phthalocyanine complexes were characterized via Fouirer Transform Infrared (FTIR), Ultraviolet-Visible (UV-VIS), Proton Nuclear Magnetic Resonance (H-1-NMR), elemental analysis and Matrix-Assisted Laser Desorption/Ionization Time -of-Flight Mass Spectrometry (MALDI-TOF MS). Also, phthalocyanines modified TiO2 nanocomposites were synthesized via a hydrothermal method and characterized by Field Emission Gun Scanning Electron Microscope (FEG-SEM), X-ray Powder Diffraction (XRD), Ultraviolet-Diffuse Reflectance Spectroscopy (UV-DRS), Energy dispersive X-ray (EDX), FT-IR and Brunauer-Emmett-Teller (BET) techniques. The modified TiO2 photocatalysts were used for the decomposition of methylene blue (MB) dyestuff under visible light monitored by UV-VIS spectrophotometry. The photocatalysts enhanced activity for the decomposition of MB compared to pure TiO2, which is attributed to photosensitizer phthalocyanine anchored onto TiO2. The photocatalyst containing ZnPc and CoPc exhibited the highest photocatalytic decomposition activity of MB, which was completed in 110 min. Moreover, the reusability applications revealed that protect about 82% of the activity in 3 recycles. (C) 2022 Published by Elsevier B.V.