Photoreversible control of coumarin driven hydrophobic Ti3C2Tx MXene composite

In this study, a Ti3C2Tx MXene/coumarin (MC) composite has been designed and fabricated by the electrostatic self-assembly of the photoreversible coumarin-surfactant and Ti3C2Tx MXene, which exhibits an effective photoreversible performance. The structure of the MC composite transforms between the pleated and 3D undulating structures on irradiation with the 365/254 nm light for many cycles, thus, resulting in the conversion of the wettability between hydrophobic (123.1 degrees +/- 0.9 degrees) to almost superhydrophobic (149.5 degrees +/- 0.8 degrees) along with the Wenzel-mixed wetting regime reversible transition. Further, the gravimetric capacitance changes between 81 and 143F g(-1). This study not only demonstrates the design and preparation of an effective photoreversible and hydrophobic MC composite, but also provides a new approach to overcome the application limitations in the humid environment owing to the hydrophilic Ti3C2Tx MXene. As a result, the developed composite material exhibits a high potential of application in the photoreversible energy conversion devices. (C) 2021 Elsevier B.V. All rights reserved.