Microstructure and photocatalytic properties of Ag/Ce4+/La3+ co-modified TiO2/Basalt fiber for ammonia-nitrogen removal from synthetic wastewater

Ag/Ce4+/La3+ (1, 3, and 5 wt.%) co-modified titanium dioxide powder and modified Titanium dioxide coated basalt fiber photocatalysts were prepared via sol-gel method. The properties of the photocatalysts were characterized in detail by using transmission electron microscopy, field-emission scanning electron microscopy, UV-visible absorption spectra, X-ray powder diffraction, X-ray photoelectron spectroscopy. The results showed that the crystal of titanium dioxide photocatalyst transformed from anatase/rutile mixture phase to pure anatase phase, and the anatase crystallites size decreased after co-modifying by Ag/Ce4+/La3+. In comparison, Ag/Ce4+/La3+ co-modified titanium dioxide exhibited higher degradation efficiency than that of Ce4+/La3+ modified titanium dioxide and Ag modified titanium dioxide due to the synergistic effect of Ce4+/La3+ and Ag-0. Moreover, 3% Ag/Ce4+/La3+-TiO2 coated basalt fiber photocatalyst represented the best activity in the degradation of ammonia nitrogen wastewater. After 6 h degradation reaction, the concentration of ammonia nitrogen decreased from 60.4 mg/L to 2.8 mg/L, and the degradation rate of ammonia nitrogen reached 95.3%, about 74% of total nitrogen was removed during the process, whereas were 93.9 and 70.7% in case of 3% Ag/Ce4+/La3+-TiO2 powder, respectively. [GRAPHICS] .