Enhanced Photocatalytic CO₂-Reduction Activity of Anatase TiO₂ by Coexposed {001} and {101} Facets

Abstract

Control of TiO2 crystal facets has attracted enormous interest due to the fascinating shape-dependent photocatalytic activity of this material. In this work, the effect of the ratio of {001} and {101} facets on the photocatalytic CO2-reduction performance of anatase TiO2 is reported. A new "surface heterojunction" concept is proposed on the basis of the density functional theory (DFT) calculations to explain the difference in the photocatalytic activity of TiO2 with coexposed {001} and {101} facets.

CO2 Reduction: From the Electrochemical to Photochemical Approach

“…The influence of different surface facets is also documented in literature. Jaroniec and co‐workers showed that the {101} and {001} facets of anatase TiO 2 exhibited slightly different band edge positions based on the DFT calculations (Figure 13e) 199. The coexistence of these two facets in single TiO 2 particle would create a surface heterojunction, which facilitated the migration of the photogenerated electrons and holes to the {101} and {001} facets, respectively (Figure 13f).…”

“…e) Schematic {001}/{101} surface heterojunction. Reproduced with permission 199. Copyright 2014, American Chemical Society.…”

Recent progress of arsenic adsorption on TiO 2 in the presence of coexisting ions: A review

“…Another study concludes that {001} facets can facilitate the transfer of photo-excited electrons to the adsorbed O 2 to generate O 2 U − , which contributes to As(III) photooxidation. Further studies suggest that the synergy of low-energy {101} and high-energy {001} TiO 2 facets can enhance the photocatalytic activity of anatase TiO 2 with the spatial separation of reduction and oxidation sites in different TiO 2 facets (Roy et al, 2013;Yu et al, 2014). Therefore, the synergistic effects of different coexisting facets on the generation of radicals, and their influence on the As(III) photocatalytic oxidation process should be elucidated in the future.…”

Achieving Highly Efficient Photoelectrochemical Water Oxidation with a TiCl4 Treated 3D Antimony‐Doped SnO2 Macropore/Branched α‐Fe2O3 Nanorod Heterojunction Photoanode

“…Compared with the diurnal‐worked solar cells, inspired from the photosynthesis in nature, the technologies such as solar‐driven photoelectrochemical (PEC) water splitting or reduction of CO 2 whose working principle is to convert solar energy to chemical bonds that can be stored and off‐hour used have provided another anticipated possibility to capture the sunlight 1. A lot of materials have been employed as photoelectrodes in PEC cells, among which the α‐Fe 2 O 3 (also called hematite) is widely acknowledged as a promising candidate due to its earth‐abundant element component, physical and chemical stability, and wide spectrum absorption range in visible light region 2.…”