Enhanced photocatalytic activity and mechanism of Ti_3C_2 - OH/ Bi_2WO_6:Yb~(3+) , Tm~(3+) towards degradation of RhB under visible and near infrared light irradiation

摘要

It is an effective method to explore full spectrum responsive photocatalyst for improving their photocatalytic activity. Herein, Ti3C2-OH/Bi2WO6:Yb3+,Tm3+ composites were successfully synthesized via a facile hydrothermal method. The resultant Ti3C2-OH/Bi2WO6:Yb3+,Tm3+ composites accompanied 2D/2D heterojunction with grid-like porous structure present a significant enhancement of photoactivity towards degradation of RhB under visible and NIR light irradiation. Specifically, the 0.2-Y/T-TB2.8 composite exhibits the best photocatalytic activity for RhB removal, in which the RhB degradation efficiency was 99.8% (Vis-NIR, 30 min), 91% (Vis, 30 min), and 48% (NIR, 160 min). The excellent photocatalytic activity of the composite is attributed to the grid-like porous structure endowing it with an enhanced RhB adsorption, favorable charge separation resulting from the outstanding conductivity of the Ti3C2 - OH, and up-conversion mechanism via energy level transition of Yb3+/Tm3+. In addition, the radical capture experiments verified that the hole (h(+)) plays the important role for degradation of RhB.