Structure and optical property changes of NbO particles by Q-switched laser pulses in water

Monoclinic H-type NbO powders subjected to Q-switched laser pulses in water were characterized by X-ray/electron diffraction and optical spectroscopy to have a significant optical property change with accompanied transformation into orthorhombic T-, pseudohexagonal TT-type and an amorphous phase. The T-NbO nanoparticles were (100), (010), (001) and (01) faceted and commonly in oriented intergrowth with TT-type or amorphized domains retaining the polymerized block units of the relic H-type. Such multiple-phase nanoparticles were hydrogenated and densified to modify Raman and FTIR bands and to show visible absorptions corresponding to a broad minimum band gap of 2.3-2.8 eV for potential opto-catalytic and electrochromic applications.