Room Temperature Oxidation of Ti3C2MXene for Supercapacitor Electrodes

Two kinds of Ti3C2/TiO2 hybrids were synthesized by room temperature oxidation methods, named as Ti3C2/TiO2–nanoparticles and Ti3C2/TiO2–nanowires, respectively. Effects of reaction time and concentration of NaOH solution on the microstructures and electrochemical performances of Ti3C2/TiO2 composites were studied in details. When used as electrodes for supercapacitors, both Ti3C2/TiO2–nanoparticles and Ti3C2/TiO2–nanowires exhibit enhanced supercapacitive performances. The electrochemical measurement results show that the specific capacitances of Ti3C2/TiO2–nanoparticles and Ti3C2/TiO2–nanowires electrodes are 128 and 143 F/g at 2 mV/s, respectively, which are larger than that of Ti3C2 MXene (91 F/g). Furthermore, after 6000 charge–discharge cycles at 5 A/g, 88% and 80% of the initial capacitances are retained for Ti3C2/TiO2–nanoparticles and Ti3C2/TiO2–nanowires, respectively. Therefore, this work not only enhances the understanding of the surface states and morphology structures of Ti3C2 MXene at different reaction condition in the aqueous solutions, but also provides simple and facile ways to fabricate Ti3C2/TiO2 composites with superior supercapacitive performances.