Effect of Calcination Conditions on Porous Reduced Titanium Oxides and Oxynitrides via a Preceramic Polymer Route

A preceramic polymer route from Ti-based inorganicorganic hybrid networks provides electroconductive N-doped reduced titanium oxides (Ti(n)O2(n-1)) and titanium oxynitrides (TiOxNy) with a monolithic shape as well as well-defined porous structures. This methodology demonstrates an advantageously lower temperature of the crystal phase transition compared to the reduction of TiO2 by carbon or hydrogen. In this study, the effect of calcination conditions on various features of the products has been explored by adopting three different atmospheric conditions and varying the calcination temperature. The detailed crystallographic and elemental analyses disclose the distinguished difference in the phase transition behavior with respect to the calcination atmosphere. The correlation between the crystallization and nitridation behaviors, porous properties, and electric conductivities in the final products is discussed.