Facile Synthesis of Highly Ordered Mesoporous and Well Crystalline TiO₂: Impact of Different Gas Atmosphere and Calcination Temperatures on Structural Properties

Abstract

Ordered mesoporous TiO2 nanoparticles with amorphous pore walls were synthesized by a facile one pot template synthesis. The samples were heat treated at different temperatures under oxidizing (air), inert (N2), and reducing (N2/H2) conditions before removing the template under air atmosphere at 350 °C. The use of N2/H2 or N2 atmospheres can effectively reduce the crystallite size by 2 nm compared to the calcination in air, leading to a better ordering of the mesoporous system than in the case of the calcination under air. The phase analysis of the powder diffraction data shows that the anatase content remains constant with temperature and is fed by an amorphous precursor and consumed by rutile when it is formed.