Solution-free synthesis of MXene composite hybrid nanostructures by rapid Joule heating†

MXene-based composite hybrid nanostructures have attracted considerable attention in recent years due to their potential for enhanced electrochemical, electronic and optical performances. However, conventional solution-based methods for fabricating MXene composites suffer from the drawback of MXene oxidation during synthesis. In this study, we present a solution-free approach using rapid Joule heating to overcome this limitation. By applying rapid thermal shock to the MXene substrate loaded with precursors, we successfully synthesized MXene composite hybrid nanostructures incorporating various components, including Pt, Co, Cu, Ni, Fe, Pd, and their alloys. Our experimental results show that the rapid Joule heating technique has several significant advantages, including the ability to synthesize various MXene composite hybrid nanostructures with minimized MXene oxidation, uniform distribution of hybrid components without severe aggregation, and homogeneous polyelemental alloy synthesis. We demonstrate the effectiveness of our approach through the synthesis of a Pt-MXene nanocomposite, showing remarkable electrocatalytic activity for the HER. The Pt-MXene exhibits a low overpotential for the HER and excellent stability, arising from the preserved active sites on MXenes, uniform distribution of Pt nanoparticles, and strong interaction between the metal and MXene. The rapid Joule heating technique presented in this study enables the successful synthesis of a wide range of hybrid materials without compromising the unique properties of MXenes, making them suitable for various applications where the synergistic effect of MXene composites can yield significant performance enhancements.