New Mesostructured Porous TiO₂ Surface Prepared Using a Two-Dimensional Array-Based Template of Silica Particles

Abstract

Mesoporous photocatalytic titanium dioxide films with periodic structures were prepared by molding from two-dimensionally ordered arrays of monodisperse SiO2 particles. The morphology of the porous structures in these films was dependent upon the annealing temperature. The photocatalytic activity of the films was confirmed, as evidenced by the photodeposition of silver on the textured film surfaces. Attachment of the free-standing films to rigid supports allowed us to locate specific microscopic areas at will and to monitor the progress of the silver photodeposition in these areas using optical microscopy and scanning electron microscopy, with both secondary electron and backscattered electron detection. However, the repeated electron beam exposure in these selected areas was found to adversely affect the photoreducibility. Although the detailed film morphology did not affect the macroscopic photocatalytic activity, we found subtle differences in the silver nucleation process which depended upon the pore wall thickness.

The influence of the interfacial properties of composite catalyst material on the photocatalytic conversion of TiO_2 layer silicates

“…4. In many previous publications a value of E g = 3.2 eV was determined for bulk TiO 2 [3]- [8,44]. The Table 1 also reveals that the value of E g for calcinated solgel TiO 2 is further decreased, which can be explained by an increase in the extent of crystallinity and in particle size of TiO 2 .…”

“…Preparation of TiO 2 has been the subject of a large number of publications [1]- [8]. The majority of these works describes titanium dioxide products prepared by controlled hydrolysis of titanium(IV) alkoxides.…”

TiO₂ Periodic Structures Fabricated via Top-down and Bottom-up Approaches with a Viewpoint of Photonic Crystal

“…2). 15 In the case of the films heated at 450°C, which has bulblike structures, the Ag photodeposition was not specifically localized on any particular part of the microtextured surface (Fig. 2a).…”

“…13 For this chemical application, a photonic crystal composed of functional materials is required. Over few years, the author struggle to fabricate such electrochemically functional photonic crystals both bottomup [14][15][16][17][18][19][20][21][22] and top-down techniques, and try to examine the photonic and electrochemical characteristics.…”

Single-site photocatalysts with a porous structure

“…Thus, it is expected that more active sites which are essential for catalytic reactions can be generated by the introduction of a porous structure to a semiconductor. It has been proved that semiconductor photocatalysts with porous structure show improved photochemical performances (Matsushita et al 1998;Schattka et al 2002;Anandan & Yoon 2003;Lu et al 2008).…”