Chemical Engineering Journal, Vol.191, 38-44, 2012
Application of titanate nanoflowers for dye removal: A comparative study with titanate nanotubes and nanowires
Titanate nanoflowers were synthesized through the hydrothermal reaction between anatase nanopowders and concentrated NaOH solution. The micrometer-sized nanoflower was assembled by many ultrathin nanosheets growing outside from a common central zone. This hierarchical structure with large surface area shows availability for the removal of organic pollutants from wastewater. Comparing with titanate nanotubes/nanowires, titanate nanoflowers show larger adsorption capacity and faster kinetics for the adsorption of methylene blue, and higher photocatalytic activity for the dye degradation. For titanate nanoflowers, the equilibrium data fit well with the Langmuir model with maximum monolayer adsorption capacity of 4.6e-4 mol/g; the sorption kinetics can be described by the pseudo-second-order model, and the overall adsorption process is controlled by the intra-particle diffusion mechanism; the adsorbed dye and the residual dye could be degraded completely by the subsequent photocatalysis. (C) 2012 Elsevier B.V. All rights reserved.