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Title: Influence of calcination parameters on the synthesis of N-doped TiO{sub 2} by the polymeric precursors method

In this paper, the influence of calcination parameters on the synthesis of N:TiO{sub 2} catalysts obtained through the polymeric precursors method was evaluated. The powders were prepared by annealing Ti{sup 4+} precursor resins at different temperature-time conditions in air, resulting in powders with different degrees of crystallinity for N doping, which was done by adding urea to the as-prepared powders and calcining in N{sub 2} atmosphere. The N doping process resulted in band gap narrowing of TiO{sub 2} and, varying annealing temperature and time, can be an alternative method for preferential formation of substitutional N or interstitial N. It was found that the percentage of interstitial N increased with an increase in annealing temperature, resulting in the complete absence of substitutional N at 400 °C. The photocatalytic performance of the powders was evaluated using Rhodamine-B and Atrazine solutions under ultraviolet and visible irradiations. The coefficients revealed that interstitial N had a positive correlation to both ultraviolet and visible photoactivity. In contrast, substitutional N showed a negative correlation. Further, the ratio of substitutional N to interstitial N indicated a strong negative correlation to ultraviolet light photoactivity and no correlation to visible light photoactivity. However, substitutional N should be controlled for bettermore » photocatalytic properties. - Graphical abstract: The temperature influences to promote higher quantities of Interstitial N doped TiO{sub 2} than Substitutional and due to difference between energies levels for substitutional N doped TiO{sub 2} and Interstitial N doped TiO{sub 2}, it is presented difference on photocatalytic activity. - Highlights: • Temperature and time of synthesis of N doping TiO{sub 2} could affect the type of N (interstitial and substitutional N). • The percentage of interstitial N increased with an increase in annealing temperature. • Interstitial N improves ultraviolet and visible light degradation of color and colorless substrates (Rhod and Atraz). • Visible photoactivity may not depend only on band gap narrowing but on several factors.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Department of Materials Engineering, Universidade Federal de São Carlos, Rodovia Washington Luis KM 235 SP-310, São Carlos CEP 13565-905, São Paulo (Brazil)
  2. Department of Chemistry, Universidade Federal de São Carlos, Rodovia Washington Luis KM 235 SP-310, São Carlos CEP 13565-905, São Paulo (Brazil)
  3. (Brazil)
  4. Embrapa Instrumentação, Rua XV de Novembro 1452, São Carlos CEP 13560-970, São Paulo (Brazil)
Publication Date:
OSTI Identifier:
22334284
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 215; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ATRAZINE; CALCINATION; CATALYSTS; DOPED MATERIALS; PHOTOCATALYSIS; SUBSTRATES; SYNTHESIS; TITANIUM OXIDES