Photocatalytic decouloration of malachite green dye by application of TiO2 nanotubes.

The nanotubes of titania were synthesized in a hydrothermal system and characterized by scanning electronic microscopy (SEM), FT-IR, FT-Raman, and surface charge density by surface area analyzer. These nanomaterials were applied to photocatalyse malachite green dye degradation. Photodegradation capacity of TiO(2) nanotubes was compared to TiO(2) anatase photoactivity. Malachite dye was completely degraded in 75 and 105 min of reaction photocatalysed by TiO(2) nanotubes and TiO(2) anatase, respectively. Catalysts displayed high photodegradation activity at pH 4. TiO(2) nanotubes were easily recycled whereas the reuse of TiO(2) anatase was not effective. Nanotubes maintained 80% of their activity after 10 catalytic cycles and TiO(2) anatase presented only 8% of its activity after 10 cycles.