TiO2 Nanoribbons/Carbon Nanotubes Composite with Enhanced Photocatalytic Activity; Fabrication, Characterization, and Application

TiO₂ nanoribbons (TiO₂ NRs) loaded with FeCo-Al₂O₃ catalyst were synthesized and used as a precursor in the synthesis of TiO₂ nanoribbons/carbon nanotubes (TiO₂ NRs/CNTs) composite by a chemical vapor deposition (CVD) method. TiO₂ NRs and TiO₂ NRs/CNTs composite were characterized by XRD, FT-IR, TEM, SEM, EDX and UV-Vis spectrophotometer. The results revealed the formation of TiO₂-B and hydrogen titanate nanoribbon like structures by the hydrothermal treatment. After loading TiO₂ NRs by FeCo-Al₂O₃ catalyst and the CVD growth of carbon nanotubes, the synthetic TiO₂ nanoribbons converted entirely to TiO₂-B nanoribbons with nanopits structure. The composite composed of tube-like nanostructures forming an interlocked network from CNTs and TiO₂-B NRs. The composite shows a relatively red-shifted band gap (3.09 eV), broader and stronger UV absorption band relative to TiO₂ NRs. The photocatalytic properties of TiO₂ NRs and TiO₂ NRs/CNTs composite were studied under sunlight irradiation. The photocatalytic degradation of methylene blue (MB) dye was investigated as a function of contact time, dye concentration, and catalyst dose. The kinetics and mechanisms of degradation were discussed. TiO₂ NRs/CNTs composite showed higher stability after six runs and 50% shorter irradiation time than TiO₂ NRs photocatalyst.