Green urea synthesis catalyzed by hematite nanowires in magnetic field

The catalytic activity of hematite (alpha-Fe2O3) nanowires under the influence of magnetic field on urea synthesis is considered green. The adsorption and subsequent dissociative reaction of hydrogen, nitrogen and carbon dioxide gases on the alpha-Fe2O3 (111) nanowires were investigated using the density functional theory (DFT) method. The average adsorption energy is -4.12 kcal/mole at different sites. The adsorption of gases resulted in a difference in density and net spin of electrons from 68 to 120 and 0-21 respectively. In addition, it induces magnetic moment value of 36.33 mu B, which confirms the enhanced magnetic behaviour of hematite. alpha-Fe2O3 nanowires (NWs) synthesized by heating iron wire in a box furnace at (750-800) degrees C and as synthesized alpha-Fe2O3 nanoparticles (NPs) were received to use as a catalyst in the magnetic reaction of urea synthesis. X-ray Diffractometer (XRD) confirms the peaks of rhombohedral structure of alpha- Fe2O3 and Raman spectrum analyses confirms the alpha- Fe2O3 peaks at 410 cm(-1), 500 cm(-1) and 616 cm(-1). The needle-like shape of hematite nanowires with length ranging from 16-25) mu m and diameter from 74 to 145 nm confirmed by Field emission scanning electron microscopy (FESEM). The magnetic properties of the nanowires exhibited different levels of saturation magnetization, for alpha- Fe2O3 perpendicularly aligned direction (13.18 emu/g) and random direction (10.73 emu/ g). Urea synthesis was done under magnetic field ranges from 0.0 to 2.5 T. The activation energy of alpha-Fe2O3 NWs for urea production is lower than NPs in the range of 0-1 T, whereas it is reversed for higher magnetic induction values. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of urea at the peaks of 1690-1600 cm(-1). This green urea employing magnetically induced method could be a contender to the Haber-Bosch process currently used by the current industry which utilizes high temperature and high pressure.