Al(2)O(3)-Based Hollow Fiber Membranes Functionalized by Nitrogen-Doped Titanium Dioxide for Photocatalytic Degradation of Ammonia Gas

In recent years, reactive ammonia (NH(3)) has emerged as a major source of indoor air pollution. In this study, Al(2)O(3)-based hollow fiber membranes functionalized with nitrogen-doped titanium dioxide were produced and successfully applied for efficient heterogeneous photocatalytic NH(3) gas degradation. Al(2)O(3) hollow fiber membranes were prepared using the phase inversion process. A dip-coating technique was used to deposit titanium dioxide (TiO(2)) and nitrogen-doped titanium dioxide (N-TiO(2)) thin films on well-cleaned Al(2)O(3)-based hollow fiber membranes. All heterogeneous photocatalytic degradation tests of NH(3) gas were performed with both UV and visible light irradiation at room temperature. The nitrogen doping effects on the NH(3) heterogeneous photocatalytic degradation capacity of TiO(2) were investigated, and the effect of the number of membranes (30, 36, 42, and 48 membranes) of the prototype lab-scale photocatalytic membrane reactor, with a modular design, on the performances in different light conditions was also elucidated. Moreover, under ultraviolet and visible light, the initial concentration of gaseous NH(3) was reduced to zero after only fifteen minutes in a prototype lab-scale stage with a photocatalytic membrane reactor based on an N-TiO(2) photocatalyst. The number of Al(2)O(3)-based hollow fiber membranes functionalized with N-TiO(2) photocatalysts increases the capacity for NH(3) heterogeneous photocatalytic degradation.