Hydrothermal Synthesis of KTiO Nanotubes/Nanoparticles: A Photodegradation Study on Methylene Blue and Rhodamine B Dyes.

The degradation of methylene blue and rhodamine B dyes using potassium hexatitanate nanoparticles (KTNPs) and potassium hexatitanate nanotubes (KTNTs) synthesized via a hydrothermal method as efficient photocatalysts under UV light irradiation was investigated. The kinetics of degradation was determined for the two different catalysts--KTNPs and KTNTs--by monitoring the optical absorption of the dyes. The as-synthesized KTNPs were found to be spherical in shape with an average particle size of ∼36 ± 1.7 nm, whereas the KTNTs evidenced a tubular hollow structure with ∼7 nm internal diameter and ∼12 nm external diameter, as perused by structural and morphological studies. The larger surface area of KTNTs showed a greater impact on the photodegradation of dyes manifesting their high potential as compared to KTNPs under UV irradiation, and the reusability studies showed more than 90% (KTNTs) and 80% (KTNPs) degradation of the dyes even after the fourth cycle elucidating their stability.