Photodegradation of 1-Butyl-3-methylimidazolium Chloride [Bmim]Cl via Synergistic Effect of Adsorption–Photodegradation of Fe-TiO2/AC

Abstract

Ionic liquids (ILs) have attracted interest among researchers due to their tunable properties, which enable them to be used in a wide variety of applications. However, toxicity and biodegradation studies of ILs proved that most of the aromatic ILs, such as imidazolium, are highly toxic and non-biodegradable. Researchers have investigated several advance oxidation processes (AOPs) in order to evaluate the efficiency of the systems used to remove ILs from wastewater. However, their relatively high cost and environmental concerns have limited the application of these AOPs in industry. This research conducted a photocatalytic study using hybrid nanomaterials to evaluate the efficiency of this system as an alternative AOP system for the removal of ILs from wastewater. The synergistic effect of adsorption–photodegradation was introduced by depositing Fe-TiO2 onto functionalized activated carbon (AC). Nano-TiO2 was synthesized using the microemulsion method, then modified with a transition metal, and deposited onto oxidized AC. The photodegradation reaction of 1-butyl-3-methylimidazolium chloride [bmim]Cl was then investigated under simulated visible light irradiation. It was observed that the overall efficiency of the system increased with the increasing amount of Fe loading. Our investigation revealed that extrinsic factors such as solution pH, the initial concentration of ILs, and photocatalyst dosage significantly affect the overall efficiency of the system. The optimum condition for the system was observed at pH 10, with initial ILs at 1 mM at 1 g/L of photocatalyst. The best performance photocatalyst was 0.2Fe-TiO2/AC.

Keywords

• photodegradation
• TiO2
• ionic liquids
• activated carbon
• synergistic effect