XRD analysis:
Figure 1 displays the XRD diffractogram of VNPs@Salvia officinalis . The pattern confirms the well crystallizing of the synthesized NPs. The data are matched to the standard database of JCPDS no: 85–2422 for vanadium oxide. The signals at 2θ values of 25.18, 27.79, 44.99, 49.43, 66.67, and 70.43, are indexed as (202), (103), (401), (205), (406), and (125) planes. A similar data has been reported for V2O5 previously [24]. The Scherer’s equation was applied to calculate the crystal size of nanoparticles, that revealed 25.60 nm for the crystal size of VNPs@Salvia officinalis .