Fig. 3

TEM of hematite nanoparticles synthesized at two different temperatures in the presence of 1,2-diaminopropane as a structure-directing additive. a Nanoparticles synthesized over 24 h at 140 °C. b Higher magnification of the developing arms of a 140 °C particle. Lattice fringes are evident suggesting good crystallinity. c FFT analysis of the 140 °C particle. d Nanoparticles synthesized over 16 h at 180 °C showing the development of nanorods with aspect ratios much larger than those obtained from the phosphate-directing agents