abstract
Several methods have been used to tailor nanomaterials structure and properties. Sometimes, slight changes in the structure outcomes expressive improvements in the optical and photocatalytic properties of semiconductor nanoparticles. In this context, the influence of the metal doping and the morphology on a catalyst performance was studied in this work. Here, ruthenium doped titanate nanotubes (RuTNT) were synthesised for the first time using an amorphous Ru-containing precursor. Afterwards, the photocatalytic performance of this sample was compared to the one obtained for ruthenium titanate nanowires (RuTNW), recently reported. Two samples, RuTNW and RuTNT, were produced using the same Ru-containing precursor but distinct hydrothermal methodologies. The powders were structural, morphological and optical characterized by X-ray diffraction and fluorescence, transmission electron microscopy, Raman, X-ray photoelectron and photoluminescence spectroscopies. Distinct variations on the structural and optical properties of the RuTNT and RuTNW nanoparticles, due to ruthenium incorporation were observed. Their potential use as photocatalysts was evaluated on the hydroxyl radical photo-assisted production. Both samples were catalytic for this reaction, presenting better performances than the pristine counterparts, being RuTNT the best photocatalyst. Subsequently, the degradation of two emergent pollutants, caffeine and sulfamethazine, was studied. RuTNT demonstrated to be better photocatalyst than RuTNW for caffeine but identical performances were obtained for sulfamethazine. For both catalysts, the degradation mechanism of the pollutants was explored through the identification and quantification of the intermediate compounds produced and several differences were found. This indicates the importance of the structural and morphological aspects of a material on its catalytic performance. (C) 2020 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
keywords
PHOTOCATALYTIC DEGRADATION; RU/TIO2 CATALYSTS; METHYLENE-BLUE; TIO2; CO; NANOPARTICLES; PHOTODEGRADATION; NANOSTRUCTURES; SULFAMETHAZINE; NANOCOMPOSITE
subject category
Environmental Sciences & Ecology
authors
Barrocas, B; Oliveira, MC; Nogueira, HIS; Fateixa, S; Monteiro, OC
our authors
Sara Fateixa
Junior Researcheracknowledgements
The authors thank Fundacao para a Ciencia e Tecnologia (FCT) (projects PEst-OE/QUI/QUI0612/2019 and IF/01210/2014), and CICECO-Aveiro Institute of Materials (project POCI-01-0145FEDER-007679) financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER (Fundo Europeu de Desenvolvimento Regional) under the PT2020 Partnership Agreement. B. Barrocas acknowledge FCT for her grant (No. SFRH/BD/101220/2014). The costs resulting from the FCT hiring (S. Fateixa) is funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29. The authors also thank the Portuguese Mass Spectrometry Network (project LISBOA-01-0145-FEDER022125). The XPS analyses were performed at Centro de Materiais da Universidade do Porto.