Thermally-induced all-damage-healable superhydrophobic surface with photocatalytic performance from hierarchical BiOCl

Abstract Preparation of superhydrophobic surfaces capable of recovering both the surface chemistry and hierarchical structure is still a challenge. In this work, all-damage-healable superhydrophobic surface was fabricated by assembly of superhydrophobic and hierarchical BiOCl on lignocellulosic substrates. Fibers having thermally responsive behavior, the main component of lignocellulosic materials, act as the underlying movable substrates. By a simple heating treatment, fibers can convey the undamaged neighbored superhydrophobic coating to the damaged area. In this way, the loss of superhydrophobicity caused by rigorous mechanical destructions, even deep cuts of one hundred of micrometers wide, can be restored, mimicking the self-healing mechanism of human skin. Superior self-healing ability in surface chemistry was also confirmed. Meanwhile, the as-prepared superhydrophobic surfaces demonstrated reliable photocatalytic ability, a useful property for resisting organic contaminations. Interestingly, it was found that the photocatalytic activity can be enhanced by tuning the surface wettability. This work reported the first use of substrate material’s inherently thermally responsive property to demonstrate self-healing superhydrophobic surface with photocatalyticity, which not only promotes the application of superhydrophobic materials in complex environment, but also opens up a new perspective in designing durable superhydrophobic materials.