Interlayer engineering of Ti<inf>3</inf>C<inf>2</inf>T <inf>x</inf>MXene using graphitic carbon nitride for flexible supercapacitor

Abstract

The superior performance of the Ti3C2T x -based supercapacitor has recently gained much interest in the energy storage community. Nevertheless, its performance in most neutral electrolytes remains a challenge, plausibly due to unfavorable ion diffusion as a result of limited interlayer spacing within Ti3C2T x . Herein, protonated g-C3N4 (pg-C3N4) was composited into Ti3C2T x using layer-by-layer assembling process. The XRD measurement indicated the enlargement in the d-spacing after pg-C3N4 was introduced into Ti3C2T x . The elemental analysis found the presence of N atom within Ti3C2T x, which indicated successful incorporation of pg-C3N4. The cyclic voltammogram revealed the increase in potential window up to 1.1 V with an improved specific capacitance of 95 F g-1 at 2 mV s-1 for Ti3C2T x /pg-C3N4 in neutral MgSO4 electrolyte. Given the fact that Ti3C2T x -only electrode yielded the specific capacitance of only 77 F g-1, a better performance of the Ti3C2T x /pg-C3N4 composite could be attributed to better ion diffusion within the material. In fact, our analysis indicated that the composite showed higher degree of ion diffusion-dependent pseudocapacitive contribution when compared to Ti3C2T x .