Fabrication of TiO₂-enriched MXene microfibers to give efficient and recyclable photocatalysts for sustainable wastewater treatment

Developing an efficient photocatalyst with good recyclability is vital for the sustainability and affordability of photocatalytic technology in the treatment of wastewater. This work demonstrates a facile route for realizing robust TiO₂@Ti₃C₂T_x fibers with exceptional photocatalytic capability and recyclability. In this route, an alkalization/de-alkalization process was developed to treat a concentrated Ti₃C₂T_x suspension known as MXene sediment, followed by a wet spinning process. The pretreatment of Ti₃C₂T_x suspensions promoted the expansion of the d-spacing of stacked Ti₃C₂T_x layers in the microfibers. It was found that this was beneficial for increasing the population of TiO₂ nanoparticles grown from Ti₃C₂T_x layers. The calcination of these fibers was systematically investigated to optimize the photocatalytic performance of TiO₂@Ti₃C₂T_x fibers. Thanks to the TiO₂ nanoparticles, the resulting fibrous photocatalysts not only enabled the fast degradation of RhB dyes but also exhibited excellent recoverability from water.