Adsorption and photocatalytic degradation of methylene blue using high surface area titanate nanotubes (TNT) synthesized via hydrothermal method

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 19; no. 6; p. 1
• Main Authors: Subramaniam, M. N., Goh, P. S., Abdullah, N., Lau, W. J., Ng, B. C., Ismail, A. F.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2017; Springer Nature B.V
• Subjects: Acidity; Adsorption; Anatase; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry and Materials Science; Crystallinity; Inorganic Chemistry; Isotherms; Lasers; Linearity; Materials Science; Methylene blue; Nanoparticles; Nanotechnology; Nanotubes; Optical Devices; Optics; Photocatalysis; Photodegradation; Photonics; Physical Chemistry; Research Paper; Surface area; Surface chemistry; Surface properties; Titanium dioxide; Titanate nanotubes; Adsorption; Photocatalysis; Methylene blue
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-017-3920-9

Removal of methylene blue (MB) via adsorption and photocatalysis using titanate nanotubes (TNTs) with different surface areas were investigated and compared to commercial titanium dioxide (TiO 2 ) P25 Degussa nanoparticles. The TNTs with surface area ranging from 20 m 2 /g to 200 m 2 /g were synthesized via hydrothermal method with different reaction times. TEM imaging confirmed the tubular structure of TNT while XRD spectra indicated all TNTs exhibited anatase crystallinity. Batch adsorption rate showed linearity with surface properties of TNTs, where materials with higher surface area showed higher adsorption rate. The highest MB adsorption (70%) was achieved by TNT24 in 60 min whereas commercial TiO 2 exhibited the lowest adsorption of only 10% after 240 min. Adsorption isotherm studies indicated that adsorption using TNT is better fitted into Langmuir adsorption isotherm than Freundlich isotherm model. Furthermore, TNT24 was able to perform up to 90% removal of MB within 120 min, demonstrating performance that is 2-fold better compared to commercial TiO 2 . The high surface area and surface Bronsted acidity are the main reasons for the improvement in MB removal performance exhibited by TNT24. The improvement in surface acidity enhanced the adsorption properties of all the nanotubes prepared in this study.