A microwave promoted continuous flow approach to self-assembled hierarchical hematite superstructures

作者：Bayazit M K; Cao E; Gavriilidis A; Tang J

来源：Green Chemistry, 2016, 18(10): 3057-3065.

DOI：10.1039/c5gc02245b

In this work, a microwave promoted flow (MWPF) system to reproducibly synthesize self-assembled hierarchical hematite superstructures (Hem-SSs) using the sole precursor (Fe(NO3)(3)center dot 9H(2)O) and single mode microwave under aqueous conditions was developed. The functional characterisation by XRD, (HR) TEM, XPS, UV-vis and Raman spectroscopy proved that highly crystalline ellipsoid Hem-SSs (similar to 180 nm x 140 nm) were produced, built from primary hematite nanoparticles, 5-10 nm in size using 0.05 mol L-1 precursor concentration, 1 mL min(-1) flow rate and short reaction time (about 6 min). Particles produced via conventional heating (CH) at 120 and 140 degrees C in the same flow reactor under similar experimental conditions were found to consist of mixtures of goethite and hematite. The effects of precursor concentration (0.1 and 0.2 mol L-1) and flow rate (2 and 5 mL min(-1)) were further investigated and the synthesis mechanism was also discussed. This novel method opens a window for continuous fabrication of metal or metal oxide nanoparticles/superstructures by a green approach.

• 出版日期2016