Enhanced carbonation synthesis of FA-CaCO3 micro-nanostructures and investigation of its coating’ s superhydrophobic properties

Carbon dioxide emissions significantly impact the global climate. Utilizing carbon sequestration to convert carbon dioxide gas into stabilized carbonate minerals can help reduce greenhouse gas emissions. Superhydrophobic surfaces are widely used but their cost is too high. In this paper, fly ash was modified with nanoparticles using carbon dioxide. A low-cost fly ash superhydrophobic surface was prepared using a two-step spraying method, which has good durability under wet and cold conditions while also sequestering carbon dioxide and alleviating the greenhouse effect. The coating could achieve superhydrophobic conditions when the modification conditions were 20 °C, 960 r·min^-1, 3–5 wt% Ca(OH)₂, and the CO₂ flow rate was controlled within 120 mL min^-1. The coating has excellent freeze-thaw resistance and retains its hydrophobic properties after being tested in >15 freeze-thaw cycles.