Fig. 1. TEM image of YVO₄:Eu luminescent nanomaterials

Fig. 2. XRD patterns (a), and calculated line patterns (b) of YVO₄:Eu luminescent nanomaterials

Fig. 3. UV-Vis absorption spectrum of YVO₄:Eu luminescent nanomaterials

Fig. 4. Fluorescence emission spectrum of YVO₄:Eu luminescent nanomaterials

Fig. 5. FTIR spectrum of YVO₄:Eu luminescent nanomaterials

Fig. 6. Mechanism for development of barefoot impressions using YVO₄:Eu nanomaterials

Fig. 7. Barefoot impressions left on ceramic tile (a—c) and laminate floor (d—f), then developed by YVO₄:Eu luminescent nanomaterials: (a, d) are images photographed in bright field, (b, e) are images photographed under 254 nm UV light in dark field, (c, f) are magnified images

Fig. 8. Mechanism for development of footwear impressions using YVO₄:Eu nanomaterials

Fig. 9. Footwear impressions left on ceramic tile (a—c) and laminate floor (d—f), then developed by YVO₄:Eu luminescent nanomaterials: (a, d) are images photographed in bright field, (b, e) are images photographed under 254 nm UV light in dark field, (c, f) are magnified images

Fig. 10. Footwear impression left on ceramic tile then developed by electrostatic attraction method