Ingeniously enhanced ferromagnetism in chemically-reduced 2D Ti₃C₂T_X MXene

Chemical reduction is a facile and cost-effective technique for the modulation of the physical and chemical properties of nanomaterials. Herein, we demonstrate an enhancement of the magnetic behavior of Ti₃C₂T_x MXene after its chemical reduction via L-ascorbic acid treatment. Small ferromagnetic loops have been observed below 50 K for Ti₃C₂T_x prepared by hydrofluoric acid (HF) etching of Al layers from Ti₃AlC₂. Such a ferromagnetic ordering of spins was significantly enhanced via a chemical reduction of Ti₃C₂T_x with L-ascorbic acid. Ferromagnetic hysteresis loops were observed for reduced Ti₃C₂T_x (r-Ti₃C₂T_x) up to 150 K indicating a significant upshift of the paramagnetic to the ferromagnetic transition temperature, pushing towards room temperature. The enhancement of ferromagnetism and upshift of the ferromagnetic transition temperature could be attributed to the localized unpaired electron in Ti-3d orbital of the r-Ti₃C₂T_x crystal and increase in the number of unsaturated Ti atoms upon L-ascorbic acid treatment. Chemical reduction via L-ascorbic acid treatment shows a promising pathway towards the modulation and enhancement of magnetism in various MXene materials for the development of 2D metallic soft ferromagnets and spintronic devices.