An ultraefficient surface functionalized Ti3C2Tx MXene piezocatalyst: synchronous hydrogen evolution and wastewater treatment

The Ti3C2Tx 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 Ti3C2Tx. The theoretical calculation of surface functionalized Ti3C2Tx-FOTS reveals that its Si–O bond causes localized lattice distortion and enhances the noncentrosymmetric structure on the Ti3C2Tx surface. Ti3C2Tx-FOTS exhibits significantly higher butterfly loops than pristine Ti3C2Tx. The calculated rate constant of Ti3C2Tx-FOTS for dye degradation was 0.9 min−1, 15-fold higher than that of Ti3C2Tx-CPTMS and 111-fold higher than that of pristine Ti3C2Tx. The hydrogen evolution rate of Ti3C2Tx-FOTS is 900.46 μmo1 g−1 h−1, three times higher than that of Ti3C2Tx. The bifunctional surface functionalized Ti3C2Tx-FOTS can simultaneously catalyse the hydrogen evolution reaction (HER) and decomposition of wastewater, demonstrating that Ti3C2Tx-FOTS, obtained through the surface engineering of Ti3C2Tx, is a superior piezocatalyst.