The Raman spectra (Figure ) of the as-prepared h-WO3@Ti nanowires (NWs) are registered as well. However, Raman spectra are very sensitive to the presence of oxygen vacancies. The prepared h-WO3 is found to be pure h-WO3. In the Raman spectrum of the hexagonal WO3@Ti sample, the main bands at 777.5, 723.12, and 635.5 cm -1 are characteristic of the O-W-O stretching vibrations. 27a, 28 Generally, the Raman spectrum of h-WO3 nanowires exhibited overlapping bands in the region of 600 -800 cm -1 . Another considerable difference is, that exclusively in the Raman spectra of h-WO3 NWs terminal W=O stretching modes are recognizable in the interval of 925 -965 cm -1 . These peaks are common for all types of WO3 hydrates, and in some cases the appearance of these bands is attributed to surface humidity. The XPS spectra (Figure ) show only the O-W peaks confirming the presence of water molecules.