Alkaline‐Earth Metal Ca and N Codoped TiO₂ with Exposed {001} Facets for Enhancing Visible Light Photocatalytic Activity

Abstract

Alkaline‐earth metal Ca and N codoped TiO2 sheets with exposed {001} facets were obtained through a one‐step hydrothermal process. The codoped TiO2 appears as microsheets with length of 1–2 μm and thickness of 100–200 nm. The X‐ray diffractometer and X‐ray photoelectron spectroscopy results confirm that Ca and N codoped TiO2 has higher crystallinity than N‐doped TiO2, as well Ca, N atoms were successfully codoped into TiO2 as interstitial Ca and interstitial N or an O–Ti–N structure, respectively. Compared with N monodoped, further alkaline‐earth Ca codoped has little influence on the energy bands of TiO2 except slightly elevating the conduction band edge at a value of 0.02 eV. The hydroxyl radicals (•OH) producing and photocatalytic experiment shows that Ca and N codoped can effectively decrease the generation of recombination centers, and enhance separation efficiency of photo‐induced electrons and holes as well as the photocatalytic activity of TiO2. The codoped photocatalyst has the highest photocatalytic activity when Ca doped ratio reach 0.48%. Excess Ca doped will weaken the crystallization of anatase TiO2, form charge center, produce new recombination centers and finally reduce the photocatalytic activity of TiO2.

Carbon-doped titania nanoplates with exposed {001} facets: facile synthesis, characterization and visible-light photocatalytic performance

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A facile synthesis of CdSe quantum dots-decorated anatase TiO2 with exposed {0 0 1} facets and its superior photocatalytic activity

“…Metal or non-metal ions doping of T001 can tune its electronic structure and thus obtain visible-light-responsive photocatalysts [11][12][13][14]. However, the dopants can easily become the recombination centers for charge carriers and lower stability of the doped materials.…”

Synthesis and characterization of carbon modified TiO2 nanotube and photocatalytic activity on methylene blue under sunlight

“…The nanoscale TiO 2 , especially the TiO 2 nanotube (TNT) has better photocatalytic activity than TiO 2 powders because of its large specific surface area [7,8]. But the forbidden bandwidth of anatase TiO 2 is relatively large, and reduced its photocatalytic efficiency [9][10][11]. In order to increase the utilization efficiency of TiO 2 on solar energy, researchers do a lot of works from decreasing the forbidden bandwidth of TiO 2 and suppressing the recombination of electrons and holes [12,13].…”