Reusable hybrid nanocomposites for clean degradation of dye waste under visible light

• Published in: Materials today communications 2022-03, Vol.30, p.103091, Article 103091
• Main Authors: Colbea, Claudiu, Oancea, Petruta, Puiu, Mihaela, Galaon, Toma, Raducan, Adina
• Format: Article
• Language: English
• Subjects: Azo dyes oxidation; Photocatalysis: kinetics; Photosensitized TiO2
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2021.103091

Herein we report on the degradation performance of three phthalocyanine-photosensitized TiO2 nanocomposites on waste dyes such as Ponceau 4R, Sella Fast Black, Congo Red, Select Brown, Indigo Carmine, Brilliant Blue, Fuchsin, Fluorescein and Naphthol Yellow S. All experiments were carried on at neutral pH, in ambient conditions, requiring only visible light and no additional oxidants. Chlorinated copper (II) α-phthalocyanine (αClCuPc), copper (II) β-phthalocyanine (βCuPc), and tetra-sulfonated copper (II) β-phthalocyanine (βSCuPc) increased the decolourization efficiency of TiO2 from moderate to high degrees, i.e., 30–100%, even for recalcitrant azo-dyes such as Ponceau 4R, Sella Fast Black, Congo Red and Select Brown. Moreover, the photosensitized catalysts display good thermal, operational stability, and reusability, providing total organic carbon (TOC) removal above 50% within 180 min in batch conditions. The reactive oxygen species were generated in the presence of dissolved oxygen, through the activation of phthalocyanine/TiO2 and it can be combined further with enzymatic/microbial treatment to achieve total mineralization. •Phthalocyanine-sensitized TiO2 nanocomposites were synthesized and characterized.•ROS were generated in the presence of dissolved oxygen under visible light.•Enhanced degradation kinetics was achieved on azo-, indigoid and trityl dyes.