Red shift of absorption spectra of metal-doped TiO2 coatings

Electronic structure and optical properties of non-metals (N, S, F, P, Cl) -doped cubic NaTaO3 were investigated systematically by density functional theory (DFT). The results showed that the substitution of (N, S, P, Cl) for O in NaTaO3 was effective in narrowing the band-gap relative to the F-doped NaTaO3. The larger red shift of the absorption edge and the higher visible light absorption at about 520 nm were found for the (N and P)-doped NaTaO3. The excitation from the impurity states to the conduction band may account for the red shift of the absorption edge in an electron-deficiency non-metal doped NaTaO3. The obvious absorption in the visible light region for (N and P)-doped NaTaO3 provides an important guidance for the design and preparation of the visible light photoactive materials.

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Quinoline-annulated chlorins and chlorin-analogs

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424616500036 ◽

2016 ◽

Vol 20 (01n04) ◽

pp. 265-273 ◽

Cited By ~ 8

Author(s):

Joshua Akhigbe ◽

Mengxi Yang ◽

Michael Luciano ◽

Christian Brückner

Keyword(s):

Absorption Spectra ◽

Functional Group ◽

Bathochromic Shift ◽

Red Shift ◽

Simple Strategy

The OsO4-mediated dihydroxylation of quinoline-annulated porphyrin generates a quinoline-annulated dihydroxychlorin in a regioselective fashion. Its dihydroxypyrroline moiety, located at the opposite of the annulated pyrrole, is susceptible to the same functional group interconversions we previously demonstrated for non-annulated dihydroxychlorins: oxidations to the corresponding dione, lactone, and dialkoxymorpholine derivatives. The quinoline-annulated chlorin and derivatives are all characterized by absorption spectra that are much broadened and between 130 and 220 nm red-shifted compared to their non-annulated analogs. Absorbance maxima in the NIR up to well above 800 nm were recorded. We attribute the bathochromic shift to their extended [Formula: see text]-systems and inferred non-planarity, highlighting that quinoline-annulation is a particularly effective and simple strategy to red-shift the absorption spectra of chlorins and chlorin analogs.

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C-,N- and S-Doped TiO2 Photocatalysts: A Review

Catalysts ◽

10.3390/catal11010144 ◽

2021 ◽

Vol 11 (1) ◽

pp. 144

Author(s):

Aleksandra Piątkowska ◽

Magdalena Janus ◽

Kacper Szymański ◽

Sylwia Mozia

Keyword(s):

Carbon Dioxide Reduction ◽

Air Purification ◽

Lithium Storage ◽

Tio2 Photocatalysts ◽

Doped Tio2 ◽

Preparation Conditions ◽

Production Of Hydrogen ◽

Methods Of Synthesis ◽

Metal Doped ◽

Inactivation Of Bacteria

This article presents an overview of the reports on the doping of TiO2 with carbon, nitrogen, and sulfur, including single, co-, and tri-doping. A comparison of the properties of the photocatalysts synthesized from various precursors of TiO2 and C, N, or S dopants is summarized. Selected methods of synthesis of the non-metal doped TiO2 are also described. Furthermore, the influence of the preparation conditions on the doping mode (interstitial or substitutional) with reference to various types of the modified TiO2 is summarized. The mechanisms of photocatalysis for the different modes of the non-metal doping are also discussed. Moreover, selected applications of the non-metal doped TiO2 photocatalysts are shown, including the removal of organic compounds from water/wastewater, air purification, production of hydrogen, lithium storage, inactivation of bacteria, or carbon dioxide reduction.

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