Influence of calcination parameters on the synthesis of N-doped TiO2 by the polymeric precursors method

Autor(es)

Dawson, Margaret ^[1] ; Soares, Gabriela Byzynski ^{[2, 3]} ; Ribeiro, Caue ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

^[3] Embrapa Instrumentacao, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Solid State Chemistry; v. 215, p. 211-218, JUL 2014.
• Citações Web of Science: 9

Resumo

In this paper, the influence of calcination parameters on the synthesis of N:TiO2 catalysts obtained through the polymeric precursors method was evaluated. The powders were prepared by annealing Ti4+ 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-2 atmosphere. The N doping process resulted in band gap narrowing of TiO2 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 degrees 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 better photocatalytic properties. (C) 2014 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 09/10998-3 - Avaliação de parâmetros cinéticos envolvidos na fotodegradação de pesticidas catalisada por nanopartículas de TiO2: estudos comparativos sobre a contribuição de processos de transferência de carga e oxidação por radicais livres
• Beneficiário: Gabriela Byzynski Soares
• Modalidade de apoio: Bolsas no Brasil - Doutorado