*3.1. Materials*

Tetrabutyl titanate (C16H36O4Ti, TBOT, ≥99%) and anhydrous ethanol (C2H6O, ≥99.8%) were purchased from Aladdin Biochemical Technology Co., Ltd., Shanghai, China. Lithium fluoride (LiF), magnesium sulfate (MgSO4), hydrochloric acid (HCl), sodium silicate (Na2O·nSiO2), sodium hydroxide (NaOH), and methylene blue (C16H18N3ClS, MB) were all obtained from Sinopharm Chemical Reagent Co., Ltd., Shanghai, China. The Evonik Degussa P25 was provided by Evonik Industries AG, Frankfurt, Germany. Deionized water was used.
