Synthesis of TiO2-Carbon Nanotubes through ball-milling method for mineralization of oxamic acid (OMA) by photocatalytic ozonation

• Type: Article in International Scientific Journal
• Date: 2017

Authors

Carla Orge (Author) FEUP; O.S.G.P. Soares (Author) FEUP; Joaquim Luís Faria (Author) FEUP; Manuel Fernando R Pereira (Author) FEUP

Journal

Title: Journal of Environmental Chemical Engineering

Vol. 5

Pages: 5599-5607

ISSN: 2213-3437

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 7 Citations

ISI Web of Science

Scopus - 15 Citations

Other information

Authenticus ID: P-00N-3RQ

DOI: 10.1016/j.jece.2017.10.030

Abstract (EN): Several TiO2-carbon nanotube composites were prepared by ball milling procedure. Prepared materials were characterized by several techniques, including N-2 equilibrium adsorption isotherms, thermogravimetric analysis, elemental analysis, X-ray diffraction spectra and transmission emission microscopy, and tested in the mineralization of oxamic acid (OMA) by photocatalytic ozonation. The influence of milling conditions was evaluated and the performance was compared with samples synthesized by conventional procedures. Independently of the milling time, a high amount of OMA, approximately 70%, is removed in the first 10 min of reaction by composites of commercial TiO2 (P25) and carbon nanotubes (MWCNT). In the best conditions, the milled sample presents a reaction rate constant of 0.099 min(-1), in contrast to 0.082 min(-1) obtained with conventional composite. The presence of N-groups produces a negative effect, especially when N-precursor was added during P25 composite preparation, removing 30% of OMA after 10 min of reaction and decreasing the removal rate to approximate to 0.050 min(-1). The OMA degradation is significantly more efficient in the presence of the milled composites containing synthesized TiO2 (SG) when compared to the composite prepared by the conventional procedure increased OMA removal from 40% to 70% after 30 min of reaction. The reaction rate constant of milled sample with original MWCNT (0.032 min(-1)) is considerably higher than observed with unmilled (0.012 min(-1)). A remarkable conversion is observed for all SG milled composites during the first 30 min of reaction and the presence of Fe is advantageous, since Fe can promote the O-3 decomposition into HO center dot radicals and surface reactions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9