g‐C<sub>3</sub>N<sub>4</sub>/TiO<sub>2</sub> Composite Film in the Fabrication of a Photocatalytic Air‐Purifying Pavements
Yu Huang, Jing Zhang, Zhenyu Wang, Yan Liu, Pengge Wang, Junji Cao, Wingkei Ho
Abstract
The fabrication of a photocatalytic air‐purifying pavement with a facile loading route, long depolluting period, and excellent deNO x activity under weak solar irradiation is essential for ambient air purification. Herein, a promising methodology is developed relying on the exploitation of a graphitic carbon nitride/TiO 2 (g‐C 3 N 4 /TiO 2 ) composite hydrosol at room temperature. The TiO 2 hydrosol can act as a source of photocatalyst and dispersant for g‐C 3 N 4 during loading. The photoinduced hydrophilicity, adhesive force, and regeneration tests in the laboratory show the long‐term deNO x application potential of g‐C 3 N 4 /TiO 2 coatings. Field studies indicate that the NO removal rate is 70.7% of g‐C 3 N 4 /TiO 2 ‐coated pavement in the morning (07:00–10:00) and afternoon (17:00–19:00), at which times solar radiation is weakest. The deNO x efficiency is influenced by solar irradiation and traffic volume. The latter exerts a more significant influence on deNO x efficiency than the former. A desirable route in fabricating a photocatalytic air‐purifying pavement is provided and offers a promising photocatalyst suitable for outdoor environmental remediation.