Encapsulation of carbon dots in fluorine-containing silica nanoparticles towards UV-to-blue, superhydrophobic, and self-cleaning agricultural coatings

It is significant to develop a simple preparation process to obtain a transparent, robust, and superhydrophobic agricultural coating for plant growth. Here, we obtained a sol solution containing fluorinated silica nanoparticles with encapsulated carbon dots (POS-SiO 2 -CDs, ∼50 nm) by co-hydrolysis of tetraethylorthosilicate (TEOS) and 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS) under the catalysis of NH 3 ·H 2 O. The sol solution was easily coated onto PE film by spraying to form a transparent UV-to-blue superhydrophobic coating. The POS-SiO 2 -CDs solid powder exhibited blue fluorescence emission (FL) with a quantum yield (QY) of 22.15 % and superamphiphobic properties. We introduced epoxy resin as a binder to improve the mechanical stability of the light-conversion superhydrophobic coating (POS-SiO 2 -CDs/Epoxy). By adjusting the ratio of epoxy resin to POS-SiO 2 -CDs nanoparticles, the optimal coating fabricated via a simple spraying process had a static water contact angle (WCA) of 155° and a rolling angle (SA) of less than 5°. The average transmittance of the coated glass in the visible light range (400–800 nm) reached 80.1 %. Meanwhile, the coating has stable FL emission, good anti-fouling performance, mechanical stability, and excellent flexibility. The rapidly constructed coating without complex modification may provide a potential advantage for manufacturing large-area, robust, superhydrophobic, and self-cleaning agricultural coatings.