We investigated

the morphology and structure of the as-obtained precipitate by TEM, SEM, and SAED, respectively. When the solvent of the whole system is only water (none of EG), a dark-green precipitate is produced immediately after the FeSO4 solution is dropped into excessive NaOH solution. In contrast to pure aqueous solution, the precipitate of ferrous hydroxide in the H2O-EG mixture solution was white at the beginning and turns green then dark-green gradually. The precipitate of ferrous hydroxide obtained in pure aqueous solution is also known as ‘green rust’ in the crystal lattice of which iron(II) ions are easily substituted by iron(III) ions produced by its progressive oxidation [35–37]. However, the oxidation process is inhibited in the H2O-EG mixture solution because of the reducing power of EG. All forms of green rust 5-Fluoracil are more complex and variable than the ideal iron(II) hydroxide compound. TEM images of the precipitate (Figure 4a) obtained in H 89 concentration pure aqueous solution show that there are two kinds of products at least; one of them is a very thin nanoplate with a diameter of about 50 nm, and the other is a needle-shaped nanoparticle. TEM and SEM images (Figures 4b and 5a,b) of the end product of this precipitate after aging for 24h in 90°C show that the obtained product is a mixture of polygonal particles and fiber-like particles. The sizes

of the polygonal particles are about 50 to 100 nm. However, no rod-like or fiber-like nanoparticles can be found in the TEM and SEM images of the as-obtained ferrous hydroxide precipitate (Figure 4c,d) in the H2O-EG mixture solution. Ferrous hydroxide obtained in the H2O-EG mixture solution forms a large-scaled film rather than plate-like and rod-like nanoparticles in pure aqueous solution. Also, according to its SAED pattern (Figure 4e), the ferrous hydroxide film has a polycrystalline structure. TEM and SEM images of the Fe3O4 nanoplate obtained in the EG-H2O mixture solution with the ratio of EG/H2O = 3:1 and 5:1 are shown in Figure 5c,d,e,f. It

can be seen that the thickness of the Fe3O4 nanoplates decreases, and the shape of the nanoplate becomes more irregular when the concentration of EG increases. From the analysis of the above experiments, Ribonucleotide reductase it is obvious that the addition of EG affects the formation of Fe3O4 nanoplate. Figure 4 Fe(OH) 2 and the as-prepared Fe 3 O 4 . (a) TEM images of Fe(OH)2and (b) low-magnification SEM images of the as-prepared Fe3O4obtained in pure aqueous solution. It can be seen that the product is a mixture of polygonal particles and fiber-like particles. (c) SEM and (d) TEM images and (e) the SAED pattern of Fe(OH)2 obtained in the EG-H2O mixture. Figure 5 The Fe 3 O 4 nanoparticles and nanoplates prepared under different conditions. (a) TEM and (b) SEM images of the as-prepared Fe3O4 nanoparticle (EG/H2O = 0:1). (c) TEM and (d) SEM images of Fe3O4 nanoplates prepared under the condition of EG/H2O = 3:1.