Facile synthesis of Bi<inf>2</inf>Fe<inf>4</inf>O<inf>9</inf>nanoplate and its application as a novel adsorbent for Cu(II) removal

• Key Words:Adsorption;Adsorbents - Adsorption isotherms - Chemicals removal (water treatment) - Dyes - Fourier transform infrared spectroscopy - Free energy - Gibbs free energy - Heavy metals - Isotherms - Metal ions - Metals - Nanostructures - Recycling - Scanning electron microscopy - Solutions - X ray diffraction;Adsorption desorption isotherms - Adsorption kinetics and isotherm - Adsorption mechanism - Fourier transform infra red (FTIR) spectroscopy - Nano-Plate - Pseudo second order kinetics - Recyclable adsorbant - Removal of heavy metal ions
• Abstract:To our knowledge, there were hardly any reports on the application of Bi<inf>2</inf>Fe<inf>4</inf>O<inf>9</inf>for adsorptive removal of heavy metal ions. In this study, Bi<inf>2</inf>Fe<inf>4</inf>O<inf>9</inf>nanoplate was successfully fabricated through a facile hydrothermal method without addition of any template agents. The adsorption mechanism of Cu(II) and its behaviour on Bi<inf>2</inf>Fe<inf>4</inf>O<inf>9</inf>were investigated comprehensively. The adsorbents were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and the N<inf>2</inf>adsorption-desorption isotherm, respectively. The investigation on adsorption kinetics and isotherm showed that the pseudo-second-order kinetic and Langmuir isotherm models could well fit the experimental adsorption data. The maximum adsorption capacity of Bi<inf>2</inf>Fe<inf>4</inf>O<inf>9</inf>for Cu(II) was found to be 42.7 mg g^-1at short equilibrium time of 40 min and ambient temperature, which was higher than those of other adsorbents reported in literatures. Thermodynamic survey on Gibbs free energy (&Delta;G &lt; 0), enthalpy (&Delta;H &gt; 0) and entropy (&Delta;S &gt; 0) demonstrated that the adsorption process was endothermic and spontaneous. Due to the adsorptive reaction of Cu²⁺on the surface, the regular plates of product were corroded to fragments, which illustrated that -OH, Fe-O, Fe-O-Fe, O-Fe-O and Bi-O involved in the adsorption process by FTIR. After recycling five times, the decline of adsorption capacity of product for Cu(II) was 7.2%, which indicated that the adsorbent could be recycled in the removal of Cu(II). Therefore, Bi<inf>2</inf>Fe<inf>4</inf>O<inf>9</inf>nanoplate might be potentially applied in the removal of heavy metal ions from aqueous solution. &copy; 2016 Elsevier B.V. All rights reserved.
• Volume:5
• Issue:1
• Translation or Not:no