First-principles Calculation Study of the Oxidation Resistance of PANI Modified Ti3C2(OH)2

The poor oxidation resistance and structural stability of Ti3C2(OH)(2) largely limit its wide applications. In this work, the surface adsorption behaviors of oxygen atoms on Ti3C2(OH)(2), polyaniline (PANI) and PANI/Ti3C2(OH)(2) composite were systematically studied and compared by first-principles calculation method. The simulation results suggest that the existence of -OH functional group can change the active sites on Ti3C2 matrix. Thereby the oxidation resistance and the structural stability of Ti3C2 matrix can be improved in some extent. Furthermore, after modifying Ti3C2(OH)(2) by PANI, the adsorption activity of PANI is much larger. Meanwhile, the adsorption energy of oxygen on the Ti3C2(OH)(2) end is significantly decreased, which is caused by the electron transfer from PANI to Ti3C2(OH)(2) , as confirmed by the Bader charge calculation. Therefore, the oxidation resistance and the structural stability of the PANI modified Ti3C2(OH)(2) composite are improved by sacrificing PANI, since oxygen prefers to adsorb and attack PANI firstly. This work provides theoretical guidelines for the improvement of oxidation resistance, structural and chemical stability of MXene.