To date, a number of nanosized magnetite crystals with a variety of morphologies, such as nanoparticles, nanospheres, hollow spheres, nanorods, nanowires, nanotubes, nanorings, nanopyramids, nano-octahedra, and flowerlike nanostructures, have been prepared by a variety of chemistry-based processing Selleckchem ACP-196 routes, including Selleckchem ABT-737 coprecipitation, thermal decomposition, microemulsion, electrochemical synthesis, and solvothermal or hydrothermal synthesis [10–15]. However, to the best of our knowledge, there are only limited reports concerning the synthesis of ultrathin magnetite nanoplate and its interesting properties. Chen’s group synthesized γ-Fe2O3 nanoplates by a solvothermal process using ethanol as solvent
and poly(vinylpyrrolidone) (PVP) as stabilizer, followed by a reduction process to generate Fe3O4 nanoplates [16]. Xu and coworkers prepared triangular Fe3O4 nanoplates between two carbon films by pyrolyzing ferrocene and sodium oxalate at 600°C [17]. In this work, we report a facile one-pot hydrothermal approach for the preparation of magnetite nanoplates by the famous Schikorr reaction. Under anaerobic conditions, iron(II) hydroxide can be oxidized
by the protons of water to form iron(II,III) oxide and molecular hydrogen. This process is described by the Schikorr reaction [18–20]: (1) The Schikorr reaction usually occurs in the process of anaerobic corrosion of iron and carbon steel in various conditions [21, 22]. Herein, this reaction was used to prepare magnetite nanoplates. In addition, ethylene glycol (EG) was introduced to this reaction 4EGI-1 mw as another solvent besides H2O to adjust the morphology and thickness of the products. In a typical procedure, a FeSO4 water solution was added to a H2O-EG mixture containing NaOH at a constant rate and under stirring after nitrogen was bubbled through the two solutions for 2 h. When the precipitation was completed, the system was undisturbed and heated to 90°C for 24 h. Methods Materials All chemicals used in our experiments were purchased and used as received without further purification. Iron(II) sulfate heptahydrate (FeSO4·7H2O, 99+%), ethylene glycol (C2H6O2, Glycogen branching enzyme 99%), and sodium hydroxide (NaOH, 98%) were purchased
from Alfa Aesar (Ward Hill, MA, USA). Sulfuric acid (H2SO4, >92%) was purchased from Shanghai Ling-Feng Chemical Reagent Co., Ltd. (Changshu City, China). Synthesis In the typical synthetic procedure of the Fe3O4 nanoplates, nitrogen is bubbled through two solutions independently: (a) 54 ml of water-EG mixture containing NaOH to obtain the final concentration of 0.22 M NaOH and (b) 6 ml of FeSO4·7H2O dissolved in 10−2 M H2SO4 to obtain the final concentration of 2.4 × 10−2 M. After 2 h, the iron(II) sulfate solution was added to the basic solution at a constant rate and under stirring. When the precipitation was completed, nitrogen was allowed to pass for another 3 min, and the system was undisturbed and heated to 90°C for 24 h in a Teflon autoclave.