A facile synthesis of porous MXene-based freestanding film and its spectacular electrosorption performance for organic dyes

Abstract In this work, we report a facile and scalable approach to synthesis a porous MXene/single-walled carbon nanotubes (p-MXene/SWCNTs) film as a freestanding electrode for the electrosorption of the organic dyes in wastewater. Dye adsorption of wastewaters is a crucial issue in the water treatment. Nevertheless, there are still several obstacles in the adsorption process hindering its practical application, such as the low efficiency and hard recycle. Electrosorption is an electrochemically accelerate adsorption technique with high removal efficiency, low cost and easy control. As a result, the as-prepared p-MXene/SWCNTs film shows spectacular adsorption capacity for methylene blue (MB) with 1068.8 mg g-1 when the applied voltage is -1.2 V, which is much higher than that of open circuit with 55.8 mg g-1. Notably, the as-prepared electrode exhibits excellent reusability without secondary pollution and the maximum adsorption capacity is up to 28403.7 mg g-1. In addition, it also possesses outstanding selective adsorption for MB and methyl orange (MO) by adjusting the pH values. We anticipate that this strategy of designing p-MXene/SWCNTs film as a freestanding electrode material will be a promising way to remove organic dyes in the wastewaters. Furthermore, we forecast that the as-synthesized p-MXene/SWCNTs film is promising to be acted as flexible electrode applicating in capacitive deionization, supercapacitors, solar cell, catalysts, and biosensors.