g‐C₃N₄/TiO₂ composite film in the fabrication of a photocatalytic air‐purifying pavement

The fabrication of a photocatalytic air‐purifying pavement with a facile loading route, long depolluting period, and excellent deNOₓ activity under weak solar irradiation is essential for ambient air purification. Herein, a promising methodology was developed relying on the exploitation of the graphitic carbon nitride/TiO₂ (g‐C₃N₄/TiO₂) composite hydrosol at room temperature. The TiO₂ hydrosol can act as a source of photocatalyst and dispersant for g‐C₃N₄ during loading. The photoinduced hydrophilicity, adhesive force and regeneration tests in the laboratory showed the long‐term deNOx application potential of g‐C₃N₄/TiO₂ coatings. Field studies indicated that the NO removal rate was 70.7% of g‐C₃N₄/TiO₂‐coated pavement in the morning (07:00–10:00) and afternoon (17:00–19:00), at which times solar radiation is weakest. The deNOₓ efficiency is influenced by solar irradiation and traffic volume. The latter exerted a more significant influence on deNOₓ efficiency than the former. This work provides a desirable route in fabricating a photocatalytic air‐purifying pavement and offers a promising photocatalyst suitable for outdoor environmental remediation. Copyright © 2020 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.