Photocatalytic inactivation of bio-aerosol using surface-active iron-titanium thin film immobilized on sustainable cementitious composite

The current research introduces a novel in-situ and visibly-active heterojunction formation concept to fabricate a sustainable antimicrobial cementitious material. To achieve this, cement mortar incorporating iron-rich industrial waste products (FWPs) was outer-coated with photocatalyst Titanium dioxide (TiO2). The proposed technique forms a novel surface-active Fe2TiO5 heterojunction oxide layer, which considerably improves the photocatalytic and antimicrobial properties of TiO2 under the visible spectrum of light. Primarily, the study evaluated the structural suitability of the developed iron-rich cementitious material in terms of its durability and strength properties. The findings indicate that the iron-rich cementitious material performed better than conventional cementitious material. After this, the effectiveness and novelty of the proposed research were examined, such that the Fe2TiO5 photocomposite was subjected to detailed microscopic investigations such as XRD, HRTEM, UV-DRS, XPS, FESEM, etc. The results verified the production of the inherent Fe2TiO5 heterojunction through the presence of Fe in the photocatalyst TiO2 lattice via the formation of ITO complex bonds. It also revealed that the Fe2TiO5 photocomposite functions effectively under visible light with an energy band gap of 2.57 eV. The antimicrobial activity of the Fe2TiO5 photocomposite was also assessed by neutralizing E.coli bioaerosols. The disinfection results indicated that the Fe2TiO5 photocomposite exhibits excellent antimicrobial properties. It achieved 69.33 % and 95-98 % antibacterial efficiency under dark and visible light, respectively. Thus, the study establishes a Fe2TiO5 photocomposite material that combines photocatalytic and antimicrobial properties, making it suitable for use as a sustainable building material. Also, it contributes to environmental sustainability by promoting a circular economy and green building practices.