An ultraefficient surface functionalized Ti 3 C 2 T x MXene piezocatalyst: synchronous hydrogen evolution and wastewater treatment

The Ti 3 C 2 T x surface contains hydroxyl groups that can be modified through self-assembled monolayers by using (3-chloropropyl) trimethoxysilane (CPTMS) and fluoroalkylsilane (FOTS). This study demonstrates that an ultrahigh level of piezoelectricity can be achieved by modifying the Si–O bond of organo-silane headgroups in Ti 3 C 2 T x . The theoretical calculation of surface functionalized Ti 3 C 2 T x -FOTS reveals that its Si–O bond causes localized lattice distortion and enhances the noncentrosymmetric structure on the Ti 3 C 2 T x surface. Ti 3 C 2 T x -FOTS exhibits significantly higher butterfly loops than pristine Ti 3 C 2 T x . The calculated rate constant of Ti 3 C 2 T x -FOTS for dye degradation was 0.9 min −1 , 15-fold higher than that of Ti 3 C 2 T x -CPTMS and 111-fold higher than that of pristine Ti 3 C 2 T x . The hydrogen evolution rate of Ti 3 C 2 T x -FOTS is 900.46 μmo1 g −1 h −1 , three times higher than that of Ti 3 C 2 T x . The bifunctional surface functionalized Ti 3 C 2 T x -FOTS can simultaneously catalyse the hydrogen evolution reaction (HER) and decomposition of wastewater, demonstrating that Ti 3 C 2 T x -FOTS, obtained through the surface engineering of Ti 3 C 2 T x , is a superior piezocatalyst.