Iron-impregnated titania composites for the decomposition of low-concentration aromatic organic pollutants under UV and visible light irradiation

Fe-TiO2 photocatalysts with different ratios of Fe to Ti were prepared by a sol-gel process using tetra-n-butyl titanium and iron(III) nitrate as Ti and Fe sources, respectively. The photocatalytic function of the prepared composites was examined for the decomposition of low-concentration (0.1 ppm) airborne benzene, toluene, ethyl benzene, and o-xylene (BTEX). The Fe-TiO2 composites were characterized by energy dispersive X-ray spectroscopy, X-ray diffraction, UV-visible spectroscopy, and Fourier transform infrared spectroscopy. The time-series ratios of outlet to inlet concentrations of toluene, ethyl benzene, and o-xylene target chemicals, as determined by the Fe-TiO2 composites under visible light exposure, were lower than or similar to those of the reference TiO2 photocatalyst. Moreover, the time-series ratios of outlet to inlet concentrations of the three compounds, as determined for the Fe-TiO2 composites, increased as the ratio of Fe to Ti increased from 0.001 to 0.010. In contrast, under UV exposure, the time-series ratios of outlet to inlet concentrations of BTEX, determined for the Fe-TiO2 composites, were similar to or higher than those obtained from the reference TiO2 photocatalyst. Fe-TiO2 composites with an optimal Fe to Ti ratio could effectively be applied for the purification of low-concentration aromatic organic pollutants.

Graphical AbstractTime-series ratios of outlet to inlet concentrations of benzene, toluene, ethyl benzene, and o-xylene determined using P25 TiO2, and Fe-TiO2 composites at varying Fe/Ti ratios (FT-0, FT-0.001, FT-0.004, FT-0.007, and FT-0.010) under visible light irradiation.Figure optionsDownload full-size imageDownload as PowerPoint slide