Removal
of toxic byproducts such as bromate (BrO<sub>3</sub><sup>–</sup>) from drinking water is a vital process. Two-dimensional (2D) titanium
carbide also known as MXene (Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub>) was proven a promising candidate for efficient reduction of metal
ions. Herein, we report for the first time the simple method for efficient
reduction of toxic bromate to bromide in water using 2D Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> nanosheets. In this reduction, the Ti–C
active layer of Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> was oxidized
and formed TiO<sub>2</sub> nanocrystals, while bromate reduced to
bromide via a self-reaction process. Reduction performance of the
Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> nanosheets was evaluated
with respect to the concentration of MXene, time, pH, and temperature.
The MXene showed excellent reduction of bromate (∼321.8 mg
BrO<sub>3</sub><sup>–</sup>/g Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub>) within 50 min, at pH 7 and 25 °C. Furthermore, MXene
nanosheets exhibited excellent sequestration performance toward bromate
in comparison with other similar materials. The high resolution transmission
electron microscopy (HR-TEM), X-ray diffraction (XRD), and X-ray photoelectron
spectroscopy (XPS) analysis confirmed the reduction of bromate and
subsequent oxidation of MXene to form TiO<sub>2</sub> nanocrystals
and Br<sup>–</sup>. This makes them attractive reductant materials
for the efficient removal of other toxic oxides present in water systems
