FTIR spectroscopy confirms a chemical bonding between the PVA matrix and the tungsten oxide nanoparticle. Fig. 4 shows the transmission spectra as a function of wavenumber for tungsten
oxide NPs, PVA nanofibers, and tungsten oxide NPs/PVA nanofi-ching, bending modes of the bridging oxygen atoms, C–H,O¼C¼O bonds and also water molecules present in the polymeric intermediate such as C–H from alkyl groups. (Table 1).