Scalable-manufactured and mechanical-robust superhydrophobic hierarchical material toward self-cleaning passive cooling

With the introduction of peak carbon dioxide emissions and carbon neutrality concepts, excessive energy loss has become an urgent global issue that needs to be solved. It is necessary to manufacture spontaneously cooling materials to accommodate the requirement for energy-saving concepts. However, the cooling materials are easily polluted by rainwater and dust in the wind, which will affect the cooling performance. Herein, the present work fabricated a mechanical-robust superhydrophobic hierarchical material for self-cleaning and passive cooling. The epoxy resin/SiO₂ layer ensures superhydrophobicity and robustness, and the magnesium titanate layer guarantees cooling performance. Hence, the material possesses a water contact angle of 151° and a sliding angle of 5.09° and can achieve 11.3 °C cooling effects than the matrix. Meanwhile, after the mechanical robustness test, the material still maintained excellent superhydrophobic performance, which is favorable to carry out applications in the field of outdoor cooling materials.