Enhancing the photocatalytic degradation of Fe-Ti over SiO2 nanocomposite material for paraquat removal

The effect of Fe and Ti loaded over SiO2 (called FeTi/SiO2) in paraquat degradation was studied for both the catalytic activity and the catalyst surface properties. Sufficient characterization techniques were used to obtain the physical and chemical properties of the FeTi/SiO2 system, such as the adsorption-desorption isotherm, surface area and porous structure, XRD diffraction, FTIR spectroscopy, UV-vis diffuse reflection spectrometry and XPS spectroscopy. The catalytic activity in paraquat degradation studies showed that the bimetallic Fe-Ti over SiO2 had higher activity than the monometallic of either Fe or Ti over SiO2 and also the order of the Fe and Ti loading was the significant parameter affecting the activity. The XPS showed that the level of Fe3+ over the catalyst was related to the obtained activity. Moreover, the optimum Fe:Ti ratio in the FeTi/SiO2 system was 1:1 (by weight). Finally, the effect of the support pretreatment (SiO2 pretreatment) was studied and showed a negative effect on the expressed activity.