Preparation of Novel Ultrathin Co doped MoS2 Nanosheets Piezocatalyst for Fast Simultaneous Decomposition of Cr(Ⅵ) and MB in Dark

Ultrathin Co doped MoS2 nanosheets(NSs) with thickness of 3.2 nm was used to simultaneously decompose Cr(Ⅵ) and MB in dark through ultrasonic vibration-assisted piezocatalytic effect. The significantly enhanced piezocatalytic performance of Co doped MoS2 NSs was found in comparison to the pristine MoS2 NSs. The high piezocatalytic activity of Co doped MoS2 NSs may originate from the large amount of charge carriers due to Co doping. The efficient separation of electron-hole pairs under spontaneous polarization were also investigated ill detail, which is responsible for reduction of Cr(Ⅵ) and oxidation of methylene blue(MB). The active species trapping experiments demonstrate that e and ·O2^- are main active substances for Cr(Ⅵ) reduction, while h+,·OH, and ·O2^- participate in MB degradation.