Kinetics of aluminum extraction from Ti3AlC2 in hydrofluoric acid

Herein we report on the influence of particle size, time and temperature on the kinetics – quantified by X-ray diffraction – of the selective extraction of Al from the ternary layered transition metal carbide, Ti₃AlC₂, when powders of the latter are immersed in hydrofluoric acid. Transmission and scanning electron microscopy, energy-dispersive X-ray spectroscopy and thermogravimetric analysis were also used to characterize the resulting powders. Increasing the temperature and immersion times, and decreasing the Ti₃AlC₂ particle size, led to faster conversion of Ti₃AlC₂ to its 2-D Ti₃C₂ counterpart. Arch-shaped edges at the ends of some Ti₃C₂ layers resembled graphene, corroborating the single-sheet structure of exfoliated Ti₃C₂. The removal of water and/or OH surface groups from Ti₃C₂ using drying in vacuum was also attempted.