Abstract
In the present studies, titanate nanotubes are synthesized using hydrolysis of commercial titania (TiO
2) nano-particle powder. The coatings of titanate nanotubes are fabricated using electro deposition method and these were subsequently processed under different conditions. These include (i) processing in atmospheric conditions, (ii) processing in vacuum, (iii) processing in Ar-gas RF-plasma, and (iv) processing in activated hydrogen (H
2) and methane (CH
4) gas mixtures using hot filament chemical vapour deposition (HF-CVD) method. It is observed that depending upon the type and processing parameters, the nanotube coatings exhibit interesting variations in the evolution and precipitation of materials phases. Typically, heating above temperatures (
T
s) ∼600
°C render dehydration process leading to collapse of nanotubular structure, however, the nature of collapse is characteristically different in each case. The treatment in activated hydrogen and carbon led to the precipitation of carbon nanotubes and nanowires, while in other cases, crystallization or amorphization took place. The samples are characterized by using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy. The results are to be discussed in terms of reduction in thermal reaction barrier due to presence of activated particles.