Photocatalytic performance of N-doped TiO2nano-SiO2-HY nanocomposites immobilized over cotton fabrics

This work reports the synthesis of nanocomposite photocatalytic materials based on nitrogen-doped TiO2nano, SiO2 and different percentages of HY zeolite (0, 12, 25 and 50%). These materials were characterized by using Fourier transformed infrared spectroscopy, X-ray diffraction, N2 adsorptiondesorption, UV-vis diffuse reflectance spectroscopy and scanning electron microscopy. The nanocomposites, which presented an energy band gap of about 3.03 eV, were immobilized on cotton fabric and their self-cleaning properties were investigated by decolourization of rhodamine B (RhB) dye in aqueous solution under simulated solar irradiation. The fabrics coated with the photocatalysts, containing and not containing zeolites, showed the same RhB decolourization (about 95%) after 5 h, excluding the situation where a large amount of HY (50%) was used in the nanocomposites. However, results obtained from high performance liquid chromatography analysis depicted that in the presence of the HY zeolite a more effective RhB degradation was achieved. In fact, even after the use of five consecutive cycles, the RhB decolourization remained high (about 85%). Generally, the photodegradation of RhB solution in the presence of cotton fabrics functionalized with TiO2nano, TiO2nano-SiO2 and TiO2nano-SiO2-0.25 HY resulted in the formation of products that exhibited a similar cytotoxic effect when compared to the untreated RhB solution and subjected to the same tested concentrations and incubation times.Salmon Landi Jr. thanks the Capes from Brazil for supports his Doctoral Fellowship (Proc. no. 13346/13-0). The authors are also grateful to the financial support of the project “AIProcMat@N2020 – Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006 and the project BioTecNorte (operation NORTE-01-0145-FEDER-000004) supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by ERDF through COMPETE2020 – Programa Operacional Competitividade e Internacionalizac¸ão (POCI), Project POCI-01-0145-FEDER006984 – Associate Laboratory LSRE-LCM and by national funds through FCT – Fundac¸ão para a Ciência e a Tecnologia for project PTDC/AAGTEC/5269/2014 and Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016). Artur Ribeiro thanks FCT for the SFRH\BPD\98388\2013 grant.info:eu-repo/semantics/publishedVersio