Scalable and sustainable production of TiCT MXene and fluorine recovery from wastewater through cryolite precipitation.

Treatment of HF or HCl/LiF etched TiCT with 0.05 M NaHCO before water washing reduces the wastewater generated by 75%. When etched with HF, cryolite (NaAlF) precipitation from spent etching waste effectively removes fluorine from this waste stream, offers insight into the etching chemistry of MAX to MXene, and provides an effective analytical tool for optimization of MXene production. Additionally, washing HF etched multilayered TiCT with 0.05 M NaHCO allows for the production of delaminated TiCT colloidal suspensions, which typically requires the use of TBAOH or DMSO for intercalation and subsequent delamination. TiCT made with HCl/LiF and washed with 0.05 M NaHCO yields a colloidal suspension with a concentration of 18 mg mL and a film conductivity of 1150 S cm.