Enhanced visible-light-induced photocatalytic NOx degradation over (Ti, C)-BiOBr/Ti3C2Tx MXene nanocomposites: Role of Ti and C doping

NOx gas pollutants have induced continuous and massive damage to our health and environment. Photocatalysts are regarded as an efficient approach for NOx degradation. Various strategies have been devoted to optimizing photocatalyst performance. In this work, a bismuth oxybromide (BiOBr) photocatalyst was successfully combined with 2D Ti3C2Tx MXene by the solvothermal treatment. It is also found that partial decomposition of Ti3C2Tx has led the in situ doping sources for BiOBr/Ti3C2Tx nanocomposite. The photocatalytic NOx purification activity of the constructed (Ti, C) co-doped BiOBr/Ti3C2Tx nanocomposites was evaluated under light illumination. The results showed that up to 61% of NOx gas has been decontaminated as short as 10 min, exceeding the pristine BiOBr and P25 titania photocatalysts. Stable performance was also achieved after several cycles, which makes (Ti,C)-BiOBr/Ti3C2Tx nanocomposites a great promise for the long term and repeated utilization. The present strategy enhanced the photoinduced electron-hole separation and transfer of the heterostructured (Ti,C)BiOBr/Ti3C2Tx. The match band structure configuration between (Ti,C)-BiOBr and Ti3C2Tx MXene and the synergistic process between photogenerated charge carrier transfer and intermediate Ti and C levels is discussed to explain the improved photocatalytic mechanism.