Fabrication of Tremella-Like Zn-Based Composite Coating with Improved Photocatalytic Degradation Performance and Robust Superhydrophobicity

In this paper, as-received Zn powder and as-prepared Zn@(ZnWO₄/ZnO) core–shell powder were used as feedstocks for plasma spraying to prepare Zn-based composite coatings and nano-ZnO was co-deposited by chemical vapor deposition induced by plasma spraying. The composition and morphology were controllable within certain range by plasma spraying power. The photocatalytic activities of the coatings were analyzed by the degradation efficiency of methyl orange (MO) solution. It was found the photocatalytic activity can be improved with ZnWO₄ decoration. The Zn/ZnO/ZnWO₄ coating which presented tremella-like surface morphology was testified to have the best photocatalytic activity under UV light irradiation among all coatings. On the other hand, the chemical surface modification with 1H,1H,1H,2H-perfluorodecyltriethoxysilane (FAS-17) was implemented to produce superhydrophobic coatings. Among all modified coatings, the ZnWO₄-containing coating with tremella-like surface structure presented the best superhydrophobicity. By the cyclic wetting and tape adhesion experiments, the tremella-like structure was proved to make a great improvement on the robustness of the Zn-based superhydrophobic coatings. The superhydrophobic and photocatalytic properties provide the possibility for the application of the coating in the fields of antifouling, antibacterial, and photocatalytic degradation of organics.

Graphical Abstract