Application of titanate nanoflowers for dye removal: A comparative study with titanate nanotubes and nanowires

Titanate nanoflower, a novel nanoporous material, has been tested as a new adsorbent for dye removal from wastewater due to its large adsorption capacity, fast kinetics and considerable photocatalytic activity. [Display omitted] ► Formation of titanate nanoflowers and their application as adsorbents/photocatalysts in wastewater treatment were reported. ► Titanate nanoflowers show large adsorption capacity and fast kinetics for the adsorption of methylene blue. ► Titanate nanoflowers show high photocatalytic activity for the dye degradation. 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−4mol/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.