Mesoporous titania photocatalysts: preparation, characterization and reaction mechanisms

Abstract

Titanium dioxide is a very important semiconductor with a high potential for applications in photocatalysis, solar cells, photochromism, sensoring, and various other areas of nanotechnology. Increasing attention has recently been focused on the simultaneous achievement of high bulk crystallinity and the formation of ordered mesoporous TiO 2 frameworks with high thermal stability. Mesoporous TiO 2 has continued to be highly active in photocatalytic applications because it is beneficial for promoting the diffusion of reactants and products, as well as for enhancing the photocatalytic activity by facilitating access to the reactive sites on the surface of photocatalyst. This steady progress has demonstrated that mesoporous TiO 2 nanoparticles are playing and will continue to play an important role in the protection of the environment and in the search for renewable and clean energy technologies. This review focuses on the preparation and characterisation of mesoporous titania, noble metals nanoparticles, transition metal ions, non-metal/doped mesoporous titania networks. The photocatalytic activity of mesoporous titania materials upon visible and UV illumination will be reviewed, summarized and discussed, in particular, concerning the influence of preparation and solid-state properties of the materials. Reaction mechanisms that are being discussed to explain these effects will be presented and critically evaluated.

Enhanced Photo-induced Charge Separation and Simulated Solar Photocatalytic Activity of α-Fe2O3/BiOCl Prepared In-situ

“…It is suggested that a low content of α-Fe 2 O 3 can increase specific surface area of heterojuctions, while a large amount of α-Fe 2 O 3 may decrease the specific surface area due to the nucleation of α-Fe 2 O 3 on the surface of BiOCl due to the limited specific surface area of BiOCl. Commonly, a high specific surface area and appropriate distribution of the pore are crucial parameters for high performance photocatalysts; these parameters facilitate electron transfer and provide a sufficient amount of interface for photocatalytic reactions, which results in higher activity (24).…”

The Relationship between the Mesostructure of WO3/TiO2 Hollow Microsphere and its Property

“…A photocatalyst with a mesoporous structure is considered to be effective in the target mentioned earlier. 28 Yang et al 7 presented a promising example to support the idea. In addition, there is almost no paper that has paid enough attention to the relationship between the mesostructure and property of the composite.…”

“…The presence of lattice distortion 8,10,12,26,27 in the composite not only facilitates the generation of photoinduced electron-hole pairs, but also postpones their recombination. Its morphology, 8,18 specific surface area, 11,23,28 microstructure, 5,6,8,11,[26][27][28] exposure degree of the active site 13,28 and so on were reported to affect its photocatalytic property. Thus, it is interesting and valuable to integrate some of the aforementioned factors to improve the photocatalytic property of a tungsten trioxide/ titanium dioxide composite.…”

Characterization and photocatalytic activity of Ti/TinOm ∙ ZrxOy coatings for azo-dye degradation

“…At the same time, the techniques of the synthesis of powder and film systems based on titanium and zirconium oxides, like impregnation, chemical vapor deposition, chemical co-precipitation from solution and sol-gel technology require the use of organic precursors, considerable time and energy consumption [18][19][20]. Aside from that, the efficiency of the use of powder photocatalysts in liquid-phase processes is reduced due to the additional phase of the powder separation from suspension at the final stage.…”