Controllable synthesis of α-Fe2O3 nanotubes with high surface area: preparation, growth mechanism, and its catalytic performance for the selective catalytic reduction of NO with NH3

Uniform FeOOH nanotubes with different thicknesses have been synthesized on a large scale by a facile template method with MoO3 nanorod as the hard template. The hydrolysis kinetics of Fe3+ has a comprehensive and crucial influence on the formation of FeOOH nanotube. The controllable synthesis of nanotubes with different thickness and inner diameter can be achieved by tuning the molar ratio of Fe3+/MoO3 and hydrolysis temperature of Fe3+ at the same time. After calcination, FeOOH nanotubes transformed to corresponding α-Fe2O3 nanotubes in which wall thicknesses vary from 50 to 128 nm. It was also found that when the molar ratio of Fe3+/MoO3 and the hydrolysis temperature of Fe3+ were fixed to 2:1 and 70 °C, respectively, the BET surface area of the obtained α-Fe2O3 nanotube is as high as 149 m2/g. The activity on the selective catalytic reduction of NO with NH3 is shape-dependent with nanotube showing a higher activity than nanoplate and nanoparticle.