One-step hydrothermal synthesis of porous Ti3C2Tz MXene/rGO gels for supercapacitor applications

Titanium carbide/reduced graphene oxide (Ti3C2Tz/rGO) gels were prepared by a one-step hydrothermal process. The gels show a highly porous structure with a surface area of similar to 224 m(2) g(-1) and average pore diameter of similar to 3.6 nm. The content of GO and Ti3C2Tz nanosheets in the reaction precursor was varied to yield different microstructures. The supercapacitor performance of Ti3C2Tz/rGO gels varied significantly with composition. Specific capacitance initially increased with increasing Ti3C2Tz content, but at high Ti3C2Tz content gels cannot be formed. Also, the retention of capacitance decreased with increasing Ti3C2Tz content. Ti3C2Tz/rGO gel electrodes exhibit enhanced supercapacitor properties with high potential window (1.5 V) and large specific capacitance (920 F g(-1)) in comparison to pure rGO and Ti3C2Tz. The synergistic effect of EDLC from rGO and redox capacitance from Ti3C2Tz was the reason for the enhanced supercapacitor performance. A symmetric two-electrode supercapacitor cell was constructed with Ti3C2Tz/rGO, which showed very high areal capacitance (158 mF cm(-2)), large energy density (similar to 31.5 mu W h cm(-2) corresponding to a power density of similar to 370 mu W cm(-2)), and long stability (similar to 93% retention) after 10 000 cycles.