Abstract
This study successfully prepared and tested sulfur- and nitrogen-co-doped TiO2-coated α-Al2O3 (S,N-doped TiO2/Al2O3) hollow fiber (HF) membranes for efficient photocatalytic degradation of gaseous ammonia (NH3). Thiourea was used as a sulfur- and nitrogen-doping source to produce a S,N-doped TiO2 photocatalyst powder. For comparative purposes, undoped TiO2 powder was also synthesized. Through the application of a phase-inversion technique combined with high-temperature sintering, hollow fibers composed of α-Al2O3 were developed. Undoped TiO2 and S,N-doped TiO2 photocatalyst powders were coated on the α-Al2O3 HF surface to obtain undoped TiO2/Al2O3 and S,N-doped TiO2/Al2O3 HF membranes, respectively. All prepared samples were characterized using XRD, TEM, XPS, UV-Vis, SEM, BET, FT-IR, and EDS. S and N dopants were confirmed using XPS and UV-Vis spectra. The crystal phase of the undoped TiO2 and S,N-doped TiO2 photocatalysts was a pure anatase phase. A portable air purifier photocatalytic filter device was developed and tested for the first time to decrease the amount of indoor NH3 pollution under the limits of the lachrymatory threshold. The device, which was made up of 36 S,N-doped TiO2/Al2O3 HF membranes, took only 15–20 min to reduce the level of NH3 in a test chamber from 50 ppm to around 5 ppm, confirming the remarkable performance regarding the photocatalytic degradation of gaseous NH3.
Subject
Filtration and Separation,Chemical Engineering (miscellaneous),Process Chemistry and Technology
Reference42 articles.
1. Sensory irritation: Risk assessment approaches;Nielsen;Regul. Toxicol. Pharmacol.,2007
2. Comparison of indoor and outdoor concentrations of acid gases, ammonia and their associated salts;Yuanqian;Environ. Technol.,1990
3. Human ammonia emission rates under various indoor environmental conditions;Mengze;Environ. Sci. Technol.,2020
4. Degradation of ammonia from gas stream by advanced oxidation processes;Koci;J. Environ. Sci. Health—Toxic/Hazard. Subst. Environ. Eng.,2020
5. Treatment of ammonia in air stream by biotrickling filter;Chou;Aerosol Air Qual. Res.,2007