Room-temperature synthesis of MIL-100(Fe) and its adsorption performance for fluoride removal from water

A novel strategy of room-temperature synthesis of MIL-100(Fe) with organic amine as deprotonating agent was proposed. The as-prepared solid product was denoted as R-MIL-100(Fe). The material was systematically characterized via XRD, FT-IR, XPS and SEM. The effects of operation parameters such as initial fluoride concentration, reaction time, initial pH and co-existing anions on the fluoride adsorption performance of the synthesized RMIL-100(Fe) were studied. The maximum fluoride adsorption capacity of R-MIL-100(Fe) was as high as 23.53 mg/g at 298 K in the fluoride solution. The results indicate that the adsorption process of fluorine on R-MIL-100 (Fe) belongs to surface adsorption and intraparticle diffusion. An excellent fluoride adsorption performance of RMIL-100(Fe) was observed in a wide pH range of 4-10. The co-existing anions including Cl-, NO3 - and SO4 2- almost had no negative effects on the adsorption performance of R-MIL-100(Fe). However, the present of CO32- or HCO3brought an obvious reduction of F- adsorption capacity of R-MIL-100(Fe). Thermodynamic study results illustrate that the adsorption process was an exothermic chemisorption. Chemical combination of iron and fluorine was confirmed by FT-IR and XPS. The strong combination brings the excellent F- adsorption performance of MIL-100 (Fe). R-MIL-100(Fe) was successfully regenerated and recycled five cycles with an excellent regeneration ability and recyclability.

Automated summary

A novel strategy for room-temperature synthesis of MIL-100(Fe) using an organic amine as a deprotonating agent was proposed, and the resulting solid product, R-MIL-100(Fe), was characterized through various methods. The study found that R-MIL-100(Fe) had a high fluoride adsorption capacity, with the adsorption process belonging to surface adsorption and intraparticle diffusion. Additionally, R-MIL-100(Fe) exhibited excellent fluoride adsorption performance in a pH range of 4-10.