Two-dimensional MXene-reinforced robust surface superhydrophobicity with self-cleaning and photothermal-actuating binary effects
Although novel two-dimensional (2D) transition-metal carbides (MXenes) have been extensively explored for various applications owing to their outstanding performance, there are few reports on the construction of superhydrophobic MXenes and their application in the field of self-propelled machines. Through inspiration from the natural nonwetting structures of the lotus leaves, we herein report the fabrication of a robust liquid-repellent surface by integration with hydrophobic multilayered/delaminated MXenes for the first time. These 2D hydrophobic MXenes play a critical role in providing rough surfaces with a unique micro/nanostructure together with dimensional effects. The constructed superhydrophobic surface originating from MXenes exhibits intriguing durability and versatility, such as self-cleaning abilities and liquid repellency. Importantly, this superhydrophobic surface also has a high photothermal-conversion capability/stability. In particular, the integration of the superhydrophobicity and photothermal-conversion capabilities of the artificial liquid-repellent surface successfully enabled remote light-driven motion in either a linear or a rotational manner. The motion was highly controllable by the precise adjustment of the laser irradiation position and design of the asymmetric structure. This work not only demonstrates the feasibility of 2D MXenes for self-propelled machines, but also provides a valuable strategy for further broadening their applications in cargo delivery, oil collection, photoresponsive robots, and biosensors.