Insights into the TiO2-Based Photocatalytic Systems and Their Mechanisms

Abstract

Photocatalysis is a multifunctional phenomenon that can be employed for energy applications such as H2 production, CO2 reduction into fuels, and environmental applications such as pollutant degradations, antibacterial disinfection, etc. In this direction, it is not an exaggerated fact that TiO2 is blooming in the field of photocatalysis, which is largely explored for various photocatalytic applications. The deeper understanding of TiO2 photocatalysis has led to the design of new photocatalytic materials with multiple functionalities. Accordingly, this paper exclusively reviews the recent developments in the modification of TiO2 photocatalyst towards the understanding of its photocatalytic mechanisms. These modifications generally involve the physical and chemical changes in TiO2 such as anisotropic structuring and integration with other metal oxides, plasmonic materials, carbon-based materials, etc. Such modifications essentially lead to the changes in the energy structure of TiO2 that largely boosts up the photocatalytic process via enhancing the band structure alignments, visible light absorption, carrier separation, and transportation in the system. For instance, the ability to align the band structure in TiO2 makes it suitable for multiple photocatalytic processes such as degradation of various pollutants, H2 production, CO2 conversion, etc. For these reasons, TiO2 can be realized as a prototypical photocatalyst, which paves ways to develop new photocatalytic materials in the field. In this context, this review paper sheds light into the emerging trends in TiO2 in terms of its modifications towards multifunctional photocatalytic applications.

Plasma Treatment as a Promising Environmentally Benign Approach for Synthesis of Valuable Multi‐gas Doped Nano‐TiO2‐P25: An Efficient Way to Boost the Photocatalytic Performance under Visible Light Illumination

“…The results confirmed the agreement between theoretical projections and experimental E VB for N 2 ‐TiO 2 ‐P25; therefore, Eqs. and can be suitable for these samples (81–83).…”

Color Tuning of Electrochromic TiO2 Nanofibrous Layers Loaded with Metal and Metal Oxide Nanoparticles for Smart Colored Windows

“…One of the widely studied heterojunctions of this case is CuO/TiO 2 , in which more efficient charge separation is observed together with a lower band gap energy in the composite form. Even though it is mostly studied for photocatalysis, 22 possible bending outcomes have not been explored thoroughly for the TiO 2 structures.…”

Photocatalytic Activity of Fibrous Ti/Ce Oxides Obtained by Hydrothermal Impregnation of Short Flax Fibers

“…Titanium oxide TiO 2 , or titania, is an intensely studied, highly effective photoactive material and photocatalyst [ 1 , 2 ]. Various synthetic methods have been proposed to improve the photoactivity of TiO 2 , based on a modified morphology of the material or doping of TiO 2 with different elements [ 3 , 4 , 5 ]. For example, the biomimetic method uses natural templates, in particular cellulose, to form photocatalytical particles with a hierarchical structure.…”

“…The effectiveness of TiO 2 photocatalysts strongly depends on the probability of the recombination of electron–hole pairs generated on the particle surface by the absorption of photons. Doping TiO 2 with metal ions lowers the probability of electron–hole recombination and improves interphase charge transfer, thus increasing the photocatalytic efficiency [ 3 , 9 ]. Researchers have proposed a number of photocatalytic TiO 2 systems mixed with ZnO [ 10 ], Cu 2 O [ 11 ], ZrO 2 [ 12 ], SnO 2 [ 13 ], WO 3 [ 14 ], and CeO 2 [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”