Active carbon/TiO2 composites for photocatalytic decomposition of benzoic acid in water and toluene in air

• Published in: Catalysis today Vol. 388-389; pp. 417 - 423
• Main Authors: Paušová, Š., Pacileo, L., Baudys, M., Hrubantová, A., Neumann-Spallart, M., Dvoranová, D., Brezová, V., Krýsa, J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2022
• Subjects: Active carbon; Adsorption; Benzoic acid; EPR spectroscopy; Photocatalytic oxidation; Toluene; Benzoic acid; Active carbon; Adsorption; Toluene; Photocatalytic oxidation; EPR spectroscopy
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2020.06.048

[Display omitted] •Stable and photoactive Active Carbon (AC)/TiO2 composite films were fabricated.•Used ACs were prepared by coconut shell pyrolysis and coal activation, respectively.•Influence of AC milling on composite photoactivity was investigated.•Production of reactive oxygen species was investigated by EPR spectroscopy.•Composite film with milled AC/TiO2 ratio 0.23 exhibits the best performance. The present work describes the preparations of active carbon (AC) – titania composites with 2 different AC/TiO2 ratios, their characterization using SEM, BET, determination of particle size, and evaluation of adsorption ability and photocatalytic activity using benzoic acid (BA) in the aqueous phase and toluene in the gaseous phase. Composite materials based on AC/TiO2 were prepared from two types of active carbon (having a BET surface area of 1737 m2 g−1 and 890 m2 g−1, respectively) and TiO2 (P25, BET surface area 45 m2 g−1) by mixing. The main studied parameter was milling of AC. Immobilized photocatalyst films were prepared by drop-casting of aqueous composite suspensions on glass substrates and drying. The composite films prepared from milled AC have much better adhesion to substrate in aqueous media than those from non-milled AC, which is due to a decrease of particle size by about 1 order during milling. The ability of composites prepared from milled AC to remove BA was more than 2.5 times higher than that of composites from non-milled AC. In comparison with TiO2, prepared composites showed similar or higher photocatalytic activity and the irradiation of AC/TiO2 composites in aqueous suspensions resulted in the generation of a comparable concentration of the hydroxyl radical spin-adduct (DMPO-OH) as with TiO2.