Hydrothermal synthesis and photocatalytic activity of combination of flowerlike TiO2 and activated carbon fibers

• 3D flowerlike TiO2 microstructure was anchored onto the surface of ACFs.
• The microstructure was assembled by rutile TiO2 rod and the formation mechanism of TiO2/ACF was explained.
• The photocatalytic activity of TiO2/ACF composite was superior to nanometer rutile TiO2.
• TiO2/ACF was easy to subside in comparison with rutile TiO2 and favorable to reuse.

The three-dimensional flowerlike TiO2 microstructure was successfully deposited on the surface of activated carbon fibers (ACFs) pre-coated with TiO2 seed layer via a hydrothermal process. The flowerlike structure was constructed by rutile-phased TiO2 rods and the formation mechanism of anchoring TiO2 onto ACF to form the TiO2/ACF composite was also discussed. The TiO2/ACF exhibited a relatively higher photocatalytic activity than the nanometer rutile TiO2 in the degradation of methyl orange, presumably due to a red shift, restraint of the photogenerated hole and electron recombination and high light-harvesting efficiency. In addition, the TiO2/ACF is favorable to reuse by emptying off the supernatant solution.