Comparative Synthesis and Electrochemical Performance of Ti3C2 MXene via LiF/HCl and HF Etching Routes

Two-dimensional transition metal carbides, known as MXenes, have been studied as promising materials for energy storage due to their high conductivity, tunable surface terminations, and layered morphology. Among them, Ti3C2 MXene is widely studied, yet its properties are strongly influenced by the synthesis route. Structural characterization by XRD showed a shift of the (002) peak from 9.5° in the MAX phase to 7.2° for LiF/HCl MXene and 6.8° for HF MXene, indicating increased interlayer spacing. Raman spectra of HF-etched MXene displayed distinct peaks at 167, 256, 412, and 603 cm?¹, along with D- and G-bands at 1350 and 1600 cm?¹, confirming defect formation and graphitic features, whereas LiF/HCl MXene showed weaker signals. FTIR analysis identified –OH (~3500 cm?¹), C=O (~1750 cm?¹), and C–F (~1200 cm?¹) groups in LiF/HCl MXene, highlighting richer surface functionalization compared to HF-derived samples. EDS confirmed elemental compositions with Ti, C, O, and F as dominant species, with LiF/HCl samples showing higher oxygen and fluorine incorporation. Electrochemical evaluation showed that HF-etched MXene achieved a specific capacitance of 312 F g?¹ at 5 mV s?¹, while LiF/HCl MXene reached 278 F g?¹ under the same conditions but showed better cycling stability, retaining 92% capacitance after 5000 cycles compared to 85% for HF MXene. These results show clear correlations between etching chemistry, structural features, and electrochemical performance. The comparative insights provide guidance for designing MXene synthesis toward safer, scalable, and high-performance electrode materials for next-generation energy storage.

Dr. Sisonke Sigonya is a Postdoctoral Research Scientist and academic coordinator at the University of South Africa’s Centre for Materials Science. Their research focuses on sensors, energy storage materials, and advanced characterization techniques, with particular expertise in MXenes and nanostructured oxides. Dr. Sigonya is recognized for elevating scientific writing and editorial standards, mentoring postgraduate researchers, and coordinating multidisciplinary teams to strengthen institutional research infrastructure. Passionate about science outreach, they also create accessible educational materials for young learners. Combining rigor with empathy, Dr. Sigonya advances materials science while empowering colleagues and students to thrive in research and education.