The invention presents a direct growth method of ZnO nanowires on civil engineering elements intended for photocatalysis for water and/or air depollution. Due to their high surface-to-volume ratio, ZnO nanowires showed excellent efficiency in the decomposition of tested dyes (AR14, MB, and MO) into less harmful products such as CO₂ , H₂O, NO³⁻, or SO₄²⁻ via a photocatalytic-induced mineralization process.
The civil engineering element coated with ZnO nanowires on its rough surface produced with this method can be integrated for instance in the development of the 5th-generation (5G) road, public garden, or in new buildings/houses. Smartly designed with new and possibly bio-based materials, 5th generation plans to make smarter roads in the near future will integrate numerous technologies including an environment depollution function. The photocatalysis process is a promising emerging solution for this aim, as it is a cheap and fast solution to degrade toxic organic compounds into harmless products. With the present invention, the photocatalysis process can be incorporated into our everyday life. Thus, incorporating metal oxide semiconductors (photocatalysts) onto civil engineering materials is a smart way to achieve this goal, as they are known to perform photocatalysis under ultraviolet lighting, or even under visible lighting with doped photocatalysts.
International patent application PCT/ EP2019/078465
Photocatalysis - Environment - Air pollution control - Water purification - Semi-conductor - ZnO - Hydrothermal method - Iron doping