Enhanced electrochemical performance of Ti3C2 MXene via a copper and silver nitrate mixed solution etching process with minimal fluorine

This work presents a novel method for synthesizing 2D Ti3C2 MXene using nitrate solution instead of hydrofluoric acid. The process involves using mixed solutions of Cu(NO3)(2) and AgNO3 to etch the Al layers of Ti3AlC2 by metal displacement reaction at room temperature, resulting in accordion-like Ti3C2 nanosheets. The obtained Ti3C2@Cu&Ag composite was evaluated as a supercapacitor working electrode. The ratio of Cu(NO3)(2) and AgNO3 was found to affect the morphology and electrochemical performance of the composite. The highest specific capacitance of 1047.5 F/g at 1 A/g in 6 M KOH was achieved with a 1:1 ratio of Cu(NO3)(2) and AgNO3 due to the synergistic effect between Cu/Ag and Ti3C2 matrix, resulting in a higher capacity than that of the pure Ti3C2 electrode. Additionally, this research provides a simple and effective procedure to synthesize various MXene-based materials for advanced electrochemical applications.