Reinforced 0D/2D CdS-Ti3C2Tx heterostructure enhancing the performance of photocatalytic benzyl alcohol dehydrogenation

The instability and poor interfacial charge transfer of semiconductor-MXene composites greatly restrict their applications in photoredox catalysis. Herein, we propose a surface passivation strategy to construct a stable and efficient CdS-MXene heterostructure, delaying the oxidation of Ti 3 C 2 T x MXene and simultaneously boosting the heterointerface charge transport, thus strengthening the cocatalytic performance of Ti 3 C 2 T x . The 2-mercaptoethanol (ME) molecules acting as crosslinkers establish intimate interfacial contact between zero-dimensional CdS nanodots and two-dimensional Ti 3 C 2 T x nanosheets, and reduce the interfacial charge transfer energy barrier, which jointly promote the efficient spatial separation of photoexcited charge carriers and result in the enhanced activity for benzyl alcohol dehydrogenation. Furthermore, the hydroxyl groups of ME passivating the unsaturated Ti atoms of Ti 3 C 2 T x , along with their thiol groups showing strong electron-donating effects and oxidation-free radical scavenging ability, cooperatively contribute to the enhanced photostability of CdS-Ti 3 C 2 T x -ME (CdS-T-M) heterostructure. This work illustrates a facile surface passivation engineering approach for reinforcing the heterointerface charge interaction and catalytic behaviors of MXene-based heterostructures.