Graphene aerogel/cellulose fibers/magnetite nanoparticles (GCM) composite as an effective Au adsorbent from cyanide solution with favorable electrochemical property
| Autor: | Arash Ghazitabar, Davoud Fatmehsari Haghshenas, Malek Naderi, Delasa Alijani Ashna |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Graphene Composite number Nanoparticle Aerogel 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials law.invention Dielectric spectroscopy Adsorption Chemical engineering law Desorption Materials Chemistry Physical and Theoretical Chemistry Cyclic voltammetry 0210 nano-technology Spectroscopy |
| Zdroj: | Journal of Molecular Liquids. 314:113792 |
| ISSN: | 0167-7322 |
| DOI: | 10.1016/j.molliq.2020.113792 |
| Popis: | In the current work, the adsorption of Au, from an industrial alkaline cyanide solution, is reported by the use of a novel synthesized adsorbant, namely graphene aerogel/cellulose fibers/magnetite nanoparticles (GCM) composite. The GCM composite was successfully synthesized by a facile and cost effective mild chemical reduction route. The synthesized composite showed a high gold adsorption capacity (130 mg·g−1) with an appropriate hydrophilicity; in addition, it had the desired mechanical strength (7 kPa at 50% strain) that makes it suitable for the industrial exploitation. The effect of contact time and GCM concentration on the gold adsorption and also the kinetic aspects of the adsorption process were studied and it was found that a pseudo-second-order model can well described the experimental data. In addition, the synthesized composite can be easily collected and separated after the adsorption step by using a magnetic separator. The desorption efficiency of the Au loaded GCM composite was 60% after 20 adsorption-desorption cycles; interestingly, the remained Au in the GCM composite after these 20 cycles could provide the GCM composite decorated by Au nanoparticles (GCM/Au) that shows promising electrochemical characteristics. According to the Cyclic Voltammetry (CV) analysis, conducted in the [Fe(CN)6]3−/4− solution, the modification of glassy carbon electrode by the GCM/Au composite resulted in an increase in the electroactivity (more than two times increase in the redox peak separation); in addition, based on the results of Electrochemical Impedance Spectroscopy (EIS), there was a significant decrease in the charge transfer resistance (Rct) of the glassy carbon electrode modified by GCM/Au composite indicating a considerable improvement in the electrical conductivity and electron transfer. |
| Databáze: | OpenAIRE |
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