Fig. 2
From: TiO2-Based Nanomaterials for Gas Sensing—Influence of Anatase and Rutile Contributions
Comparison between anatase- and rutile-predominated p-type chromium Cr-doped TiO2 nanopowders obtained by flame spray synthesis (FSS): a X-ray diffraction patterns, b TEM/SEM images, c resistive-type response R/R 0 to hydrogen at 300 °C, d diffused reflectance R Diff as a function of wavelength λ; f R, rutile content; d A, diameter of anatase crystallite; d R, diameter of rutile crystallite; R 0, electrical resistivity in the reference atmosphere (air); R, electrical resistivity under exposure to detected gas and hν, photon energy