Moreover, the stretching observed at 3,742 cm−1 is due to the free OH groups [12, 13]. The additional stretching in the Ti-KIT-6 material that appeared at 961 cm−1 is due to Ti-O-Si [12], in which Ti was attached through the hydroxyl groups of the KIT-6 silica. An increase in the peak intensity has been found for an increase in the Ti content for Si/Ti ratios of 200 to 50; this is generally considered as proof of Ti incorporation buy Anlotinib within the framework of KIT-6. Moreover, an additional stretching of Androgen Receptor agonist inhibitor Ti-O-Ti has been observed at 435 cm−1 due to the increased Ti content in Si/Ti = 50. Overall, the OH groups that represent the adsorption power
of the material were also increased in the Ti-KIT-6 samples from Si/Ti ratios of 200 to 100, and then a slight decrease was found in the 50 ratio. This increase in OH groups might be associated with the better dispersion of the isolated Ti species on KIT-6 with ��-Nicotinamide Si/Ti = 100 than for the other ratios of 200 and 50, and it is also a sign of the good hydrophilicity of the material. Figure 4 FT-IR analysis spectra of KIT-6 (calcined) and Ti-KIT-6 (calcined, Si/Ti = 200, 100, and 50 ratios) materials. The Ti(2p) XPS spectra for Ti-KIT-6 are shown in Figure 5a, for different Ti contents, where
a Ti(2p 3/2) and Ti(2p 1/2) doublet with a separation of 5.75 eV [14] can be seen. The Ti(2p 3/2) line was shifted towards a lower binding energy for an increased Ti content of Si/Ti ratios of 200 to 50. The deconvoluted XPS spectra shown
in Figure 5b,c indicates that for an increased Ti content of Si/Ti = 50, the Ti(2p 3/2) line was shifted even further to 458.0 eV, which is close to the binding energy of Ti(2p 3/2) of pure titania. As can be seen in Figure 5d,e,f, similar behavior has been noticed in the O1s spectra of the Ti-KIT-6 materials, in which the O1s line at 533 eV gradually shifted towards lower binding energies for an increased Ti content. The deconvoluted XPS spectra of Ti-KIT-6, at Si/Ti ratios of 100 and 50, depicted two peaks at 533 eV for Si-O-Si and 530.8 eV corresponding to Ti-O-Ti. These indicate that there is more free TiO2 phase formation in Ti-KIT-6(Si/Ti = 50) Smoothened than in Ti-KIT-6(Si/Ti = 100). This is also in agreement with the results of the UV-vis and TEM analyses. Figure 5 XPS analysis of Ti-KIT-6 (calcined) materials showing the difference in the different samples. (a) Overall Ti2p and (b,c) deconvolution of Ti-KIT-6 (calcined, Si/Ti = 100 and 50 ratios). (d) Overall O1s and (e,f) deconvolution of Ti-KIT-6 (calcined, Si/Ti = 100 and 50 ratios). Photocatalytic conversion of CO2 to fuels and its mechanism The reaction results of the synthesized photocatalysts are shown in Figure 6a,b,c,d,e,f.