In-situ fabrication of titanium suboxide-laser induced graphene composites: Removal of organic pollutants and MS2 Bacteriophage

Abstract

Titanium suboxides (TSO) are identified as a series of compounds showing excellent electro- and photo-chemical properties. TSO composites with carbon-based materials such as graphene have further improved water splitting and pollutant removal performance. However, their expensive and multi-step synthesis limits their wide-scale use. Furthermore, recently discovered laser-induced graphene (LIG) is a single-step and low-cost fabrication of graphene-based composites. Moreover, LIG's highly electrically conductive surface aids in tremendous environmental applications, including bacterial inactivation, anti-biofouling, and pollutant sensing. Here, we demonstrate the single-step in-situ fabrication of TSO-LIG composite by directly scribing the TiO 2 mixed poly(ether) sulfone sheets using a CO 2 infrared laser. In contrast, earlier composites were derived from either commercial-grade TSO or synthesized TSO with graphene in multi step processes. The characteristic Ti 3+ peaks in XPS confirmed the conversion of TiO 2 into its sub-stoichiometric form, enhancing the electro-catalytical properties of the LIG-TiO x composite surface. Electrochemical characterization, including impedance spectroscopy , validated the surface's enhanced electrochemical activity and electrode stability. Furthermore, the LIG-TiO x composite surfaces were tested for anti-biofouling action and electrochemical application as electrodes and filters. The composite electrodes exhibit enhanced degradation performance for removing emerging pollutant antibiotics ciprofloxacin and methylene blue due to the in-situ hydroxyl radical generation. Additionally, the LIG-TiO x conductive filters showed the complete 6-log killing of mixed bacterial culture and MS2 phage virus in flow-through filtration mode at 2.5 V, which is ∼2.5-log more killing compared to non-composited LIG filers at 500 Lm −2 h −1 . Nevertheless, these cost-effective LIG-TiO x composites have excellent electrical properties and can be effectively utilized for energy and environmental applications.