Preparation of Bi2MoO6/Ti3C2 MXene heterojunction photocatalysts for fast tetracycline degradation and Cr(vi) reduction

Abstract

In this work, a new artificial photocatalytic system has been designed based on the two-dimensional (2D) heterojunction of bismuth molybdate (Bi₂MoO₆)/Ti₃C₂ MXenes. The strong interface contact and short charge transport distance between Bi₂MoO₆ and Ti₃C₂ ensure extraordinary surface and interface charge transfer abilities. The optimized photocatalyst Bi₂MoO₆/Ti₃C₂ exhibited the highest photocatalytic activity, and its removal rates for tetracycline hydrochloride (TC) and heavy metal ion Cr(VI) were about 8.8 and 11.2 times that of pristine Bi₂MoO₆, respectively. DFT simulation calculations revealed that the stronger interaction promotes the polarization charge distribution of Bi₂MoO₆/Ti₃C₂, thereby further enhancing the separation and transfer of photoinduced electrons and holes. Meanwhile, Bi₂MoO₆/Ti₃C₂ could provide new adsorption sites, which are conducive to the interaction between pollutant molecules and the catalyst. This indicates that efficient charge separation and excellent adsorption in heterojunction photocatalysts play a key role in improving photocatalytic performance.