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@Ti3C2Tx fibers with exceptional photocatalytic capability and recyclability. In this route, an alkalization/de-alkalization process was developed to treat a concentrated Ti3C2Tx suspension known as MXene sediment, followed by a wet spinning process. The pretreatment of Ti3C2Tx suspensions promoted the expansion of the d-spacing of stacked Ti3C2Tx layers in the microfibers. It was found that this was beneficial for increasing the population of TiO2 nanoparticles grown from Ti3C2Tx layers. The calcination of these fibers was systematically investigated to optimize the photocatalytic performance of TiO2@Ti3C2Tx 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.