After 30 min, the CO2 flow rate was reduced to 10 mL/min. When equilibrium was reached, the UV light was turned on, and the reaction products were analyzed by means of MI-503 datasheet the GC. Blank tests were also conducted to ensure that the product was due to the photocatalytic reaction. The blank tests consisted of a UV illumination without the photocatalyst and a reaction in the dark with the catalyst. Results and discussion Physicochemical properties of the synthesized materials Table 1 shows the physical and textural properties of the KIT-6 and Ti-KIT-6 materials, which

were obtained by means of N2 sorption. A noticeable decrease can be seen in the surface area and pore volume of KIT-6, after Ti incorporation with different Si/Ti ratios. However, the surface area and pore volume of the Ti-KIT-6 (dried) materials were slightly higher than those of the Ti-KIT-6 (calcined) ones, which might be due to the easy incorporation of Ti in the dried weak structure of KIT-6. However, Ti can be trapped in the bulk of the dried KIT-6 material, but not in that of the rigid structure of the calcined KIT-6 one. The average pore diameter

did not change significantly and remained uniform, which might be due to the 3-D pore structure of KIT-6, which is able to accommodate the uniform isolated Ti dispersion. Table 1 Comparison of the physical properties, bandgap energy of the synthesized materials, and methane production Samples N2sorption UV-vis CH4production comparison S BET PV APD WL BE P Reference VRT752271 cost [Ti-K-6 (dried) (Si/Ti = 200)] calcined 865 1.11 6.55 – - – - [Ti-K-6 (dried) (Si/Ti = 100)] calcined 767 0.80 6.48 – - – - [Ti-K-6 (dried) (Si/Ti = 50)] calcined 730

0.67 6.45 – - – - KIT-6 (K-6) calcined 772 1.04 6.49 – - – - [Ti-K-6 (calcined) (Si/Ti = 200)] calcined 726 0.95 6.45 320 3.87 – - [Ti-K-6 (calcined) (Si/Ti = 100)] calcined 700 0.85 6.40 330 3.75 4.1 This work [Ti-K-6 (calcined) (Si/Ti = 50)] calcined 684 0.73 6.41 372 3.33 – - Anatase TiO2 powder – - – - – 0.4 [18] Aeroxide/degussa P25 TiO2 – - – - – 0.6 This work Titanium silicate (TS-1) zeolite – - – - – 2.7 [16] Ti-MCM-41 – - – - – 2.9 [16] S BET, BET specific surface area in m2/g; PV, cumulative pore volume in cm3/g; APD, average pore diameter in nm; WL, absorption edge wave length, λ, in nm; BE, bandgap energy in eV; P, production rate in μmol · gcat.−1 · h−1). The UV-vis Protirelin spectra of the calcinated Ti-KIT-6 (calcined, Si/Ti = 200, 100, and 50) are shown in Figure 1. It has been observed that with the GLUT inhibitor increased Ti content, the absorption spectra are shifted to higher wavelengths since the absorption edge wavelength changes from 320 to 372 nm (Table 1), that is, moving towards the trend of pure TiO2. Therefore, it can be observed that this increased Ti might also have more chance of making the agglomerates of TiO2 with the moisture present during the synthesis. The bandgap energies of the Ti-KIT-6 materials, corresponding to a bandgap of 3.33 to 3.