Preparation, structural characterization and photocatalytic activity of mesoporous Ti-silicates

摘要: Abstract This paper focuses on structural and photocatalytic properties of ordered mesoporous Ti-silicates, prepared by both impregnation (IMP) coprecipitation (CP) methods. Catalyst characterization was carried out inductively coupled plasma analysis, nitrogen adsorption–desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) scanning (SEM) with energy dispersive analysis (EDX). Photocatalytic activity evaluated for gaseous trichloroethylene (TCE) decomposition in a batch reactor under near-UV irradiation. Both the Ti incorporation method (IMP or CP) TiO 2 content (4.7–35.0 wt.%) had large effects characteristics whereas no important were observed respect to calcination temperature (200–600 °C). At all conditions, present as pure anatase crystallites particle diameters IMP catalysts 4.4–7.0 nm, being clearly smaller than those CP ones (12.0–19.6 nm). The structure silica at least partially preserved up 25 wt.% 33 wt.% (IMP). With increasing content, specific surface area (SSA 376–805 m  g −1 ) decreased. Similar trends pore volumes (0.6–1.2 mL g (4.5–7.5 nm) catalysts. Initial TCE degradation rate constants (0.014–0.202 min obtained increased systematically contents 35 wt.%, while ones, they levelled off above 17 wt.%. rates factor six higher measured applying method. may be explained different localization structure. During preparation, is mostly incorporated within mesopores, during synthesis, it mainly localized external surface.