Multi-branched FeO(OH) nanorods are successfully prepared using a facile one-pot solution-phase synthesis method. Their morphology and structure were characterized using field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), and Fourier transform infrared (FTIR) absorption spectrum. The results show amount of surfactant (PEO)20(PPO)70(PEO)20 (P123) and precipitant hexamethylenetetramine (HMTA) have significant effect on the shape of the particles. When 20-25 g of the P123 alcohol solution (20 wt%) is added the reaction solution containing 5.0 mL HMTA (2 mol/L) or when 18 g of the P123 alcohol solution (20 wt%) is added the reaction solution containing 10.0 mL HMTA (2 mol/L), the multi-branched FeO(OH) nanorods can be obtained. While when 19-22 g of the P123 alcohol solution (20 wt%) is added the reaction solution containing 10.0 mL HMTA (2 mol/L), the products became the Fe3O4 nanosheets with irregular shape. A possible growth mechanism of the multi-branched FeO(OH) nanorods is suggested.
Microdroplet synthesis of azo compounds with simple microfluidics-based pH control
