Layered BiOBr/Ti₃C₂ MXene composite with improved visible-light photocatalytic activity

Layered BiOBr/Ti₃C₂ (BTC) composites were synthesized by first preparing Ti₃C₂ nanosheets through the liquid etching of Ti₃AlC₂ powder and then hybridizing with BiOBr via a facile reflux process. The morphology, crystal structure, light-harvesting capacity, chemical nature of atoms and visible-light photocatalytic degradation activity were systematically studied and discussed. It was found that the introduction of Ti₃C₂ nanosheets improved UV–Vis light absorption region of BiOBr. A contact interface was formed between BiOBr nanoplate and Ti₃C₂ nanosheet due to the similar layered structures, which could accelerate the efficient separation and transfer of photoinduced electrons and holes. Thus, the obtained BTC composites showed the higher visible-light photocatalytic activity for the degradation of RhB than pure BiOBr. The generated active species were determined by the active species capture experiment and ESR spectra, showing that ^·O₂⁻ and ^·OH played a crucial role in the photocatalytic degradation of RhB. The corresponding photocatalytic mechanism was proposed. This work may provide a new insight into the construction of earth-abundant MXene-based photocatalysts with high performance and low cost.