Highly Efficient Photo Rechargeable Supercapacitor based on Ambipolar Interface of Graphitic Carbon Nitride and MXene

Abstract Dual‐functional materials for both the optically and the electrochemically active electrode enable efficient direct storage of solar energy into electrical energy. A photo rechargeable supercapacitor is developed using an ambipolar interface of MXene (Ti 3 C 2 T X ) and protonated graphitic carbon nitride under light illumination. An extraordinarily large increase of 1960 % in the electrochemical capacitance is measured under the light illumination (420 nm) compared to its dark capacitance. Ambipolar interface induces an anomalous increase in the capacitance at an ultra‐high scan rate of 1.5×10 5 mV/s under the light illumination. Moreover, the photo‐assisted, voltage of ~270 mV is generated in the rechargeable supercapacitor. The extraordinary results are attributed to the attractive interface of oppositely charged MXene and protonated graphitic carbon nitride.