Ionothermal Synthesis of Carbon/TiO₂ Nanocomposite for Supercapacitors

Abstract A facile in‐situ ionothermal strategy is designed to synthesize carbon/oxide composites with nanoporous structure. Ionic liquids play key roles in this ionothermal method as the solvents, porous structure directing templates and carbon sources. The interaction between ionic liquids and oxides greatly improves the carbon yield of ionic liquids from nearly 0 to 18 wt.%. With the synergistic effects of the high electrical conductivity of the nitrogen‐rich carbon species and the Ti³⁺ self‐doping enhanced electrical conductivity of TiO₂, C/TiO₂‐4 composite exhibits better electrochemical performance than C/SiO₂ and C/Nb₂O₅ do as a supercapacitor electrode material, delivering a high specific capacitance of 152.4 F g⁻¹ at 5 mV s⁻¹ with good capacitance retentions of 84.7%, 72.2% and 46.0% at 30, 100 and 500 mV s⁻¹, respectively.