Elsevier

Applied Surface Science

Volume 386, 15 November 2016, Pages 352-363
Applied Surface Science

Layered double hydroxide materials coated carbon electrode: New challenge to future electrochemical power devices

https://doi.org/10.1016/j.apsusc.2016.06.032Get rights and content

Highlights

  • MgAl and ZnAl LDH nanosheets were chemically synthesized and deposited over carbon electrode materials.

  • Catalytic performance of both LDHs was investigated for Fe(II) reduction reaction.

  • Satisfactory results have been achieved with the MgAl LDH material.

  • MgAl and ZnAl LDH modified carbon felt were applied in MFC as an efficient anode catalyst.

  • The LDH-modified anode significantly increased power performance of MFC.

Abstract

Layered double hydroxides (LDHs) have been widely used in the past years due to their unique physicochemical properties and promising applications in electroanalytical chemistry. The present paper is going to focus exclusively on magnesium-aluminum and zinc-aluminum layered double hydroxides (MgAl & ZnAl LDHs) in order to investigate the property and structure of active cation sites located within the layer structure. The MgAl and ZnAl LDH nanosheets were prepared by the constant pH co-precipitation method and uniformly supported on carbon-based electrode materials to fabricate an LDH electrode. Characterization by powder x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy revealed the LDH form and well-crystallized materials. Wetting surface properties (hydrophilicity and hydrophobicity) of both prepared LDHs were recorded by contact angle measurement show hydrophilic character and basic property. The electrochemical performance of these hybrid materials was investigated by mainly cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry techniques to identify the oxidation/reduction processes at the electrode/electrolyte interface and the effect of the divalent metal cations in total reactivity. The hierarchy of the modified electrode proves that the electronic conductivity of the bulk material is considerably dependent on the divalent cation and affects the limiting parameter of the overall redox process. However, MgAl LDH shows better performance than ZnAl LDH, due to the presence of magnesium cations in the layers. Following the structural, morphological and electrochemical behavior studies of both synthesized LDHs, the prepared LDH modified electrodes were tested through microbial fuel cell configuration, revealing a remarkable, potential new pathway for high-performance and cost-effective electrode use in electrochemical power devices.

Introduction

Microbial fuel cells (MFCs) are novel bioelectrochemical systems that exploit electrogenic bacterial to generate electrical power while degrading organic pollutants in wastewater [1], [2]. However, improving anode performance in MFCs remains one of the deciding factors for their applications, because the biological reactions mainly occur over its surface. During anodic bioelectrocatalysis, microorganisms oxidize organic matter and released electrons are transferred to the solid electrode material. Hence, the development of new and simple strategies to fabricate efficient anode materials to increase the bacterial loading capacity and improve substrate transport is of great interest and importance.

Nowadays, a major challenge for microbial fuel cells (MFCs) is to develop new anode materials for practical applications in bio-electroremediation devices. Commercial graphite-based materials such as carbon felt, carbon cloth, glassy carbon, carbon paper and graphite rods have been widely used as convenient materials for anode MFCs [3], [4], [5], [6]. Thus, improving anode performance is important for increasing power production. Previous research has shown that electrode performance can be improved through chemical modification of the anodes.

Clay’s minerals have emerged as one of the most promising modified electrode materials for developing high-performance due to their unique properties such as high metal dispersion, high surface area, controllable particle size and high thermal stability [7], all of which benefit the formation of highly stable and dispersed electrochemical active metal [8], [9]. Particularly interesting is the anionic clays, especially hydrotalcite-like compounds (HTs), which are relatively easy to synthesize and have an environmentally friendly nature. HTs exhibit a broad versatility which allows their synthesis with different ions for specific applications [10], [11], including degradation and adsorption of a wide variety of pollutants such as phenols, oxyanions and dyes [12], [13], [14]. Recently, Tonelli et al. [15] and Mousty et al. [16], [17] have reviewed the HT materials as electrode modifiers to be used for both electrochemical detection (chemical sensors and biosensors) and energy-storage devices.

The naturally occurring mineral hydrotalcite, Mg6Al2(OH)6CO3·4H2O, belongs to this class of materials, and consequently layered double hydroxides (LDHs) are also known as hydrotalcite-like materials. LDHs are a family of synthetic lamellar solids with positively charged brucite-like layers of mixed metal hydroxides separated by interlayer hydrated anions (Scheme 1) [18], [19], described by the general formula: [M(II)1-xM(III)x.(OH)2]x+[(An−)x/n,yH2O] (abbreviated as M(II)M(III)–A, where M(II) is a divalent metal cation, such as Mg, Mn, Ni, Zn, Co, Fe and Cu; M(III) is a trivalent metal cation, such as Al, Fe, Co, Ni, Mn and Cr; An− is an interlayer anion, such as Cl, F, CO32−, NO3 and SO42−; the value of x is between 0.2 and 0.33 generally represent the molar ratio M(II)/[M(II) + M(III)]).

As an inorganic clay that have been widely reported, layered double hydroxides (LDHs) have been subjected to intense research by the electrochemist community. However, the exploration of LDH-based materials as electrode modifiers is one of the important issues to be of concern [20], [21], [22], [23]. Previously, we reported that LDHs in which M(II) is a transition metal, undergoing a redox reaction in the range of applied potential, have been proposed as materials with improved charge transport [24], [25], [26], [27], [28]. Indeed, electron transfer within these Inorganic lamellar materials can further be promoted by two strategies: (i) the intercalation of redox active anions between the LDH layers and (ii) the presence of transition metal cations within the LDH intralayer domain, itself [17]. Accordingly, the modulation of the intrinsic properties of LDHs (electronic conductivity, redox or acid-base properties) is dependant on the nature of the cations in the layers [29], can render the LDH hybrid structure electroactive and endow redox properties to the LDH layers. However, to our knowledge, very few studies describe the electrochemical behavior of LDH in function of the cations. They have been dedicated to LDHs with Ni and Co divalent cations [28], [30], [31], [32], [33], [34], [35]. Because of their desirable properties including low cost, good biocompatibility, high catalytic activity, and high chemical stability, LDH materials could find application also as anode materials in the so-called biofuel cell, as very recently reported in literature [36], [37]. LDH modified electrodes are thus mainly prepared as a thin film coated on a working electrode surface through solvent casting, layer by layer assembly, or electrode position [38], [39], [40].

A comprehensive study of the electrochemistry of layered double hydroxides is evident to open new potentialities in regard to application in area of electrochemical devices. The current paper is devoted to investigate and hence improve electron transfer reaction using divalent cation metals containing LDH (Mg & Zn) supported on carbon electrodes. A special attention is paid on MgAl-LDH and ZnAl-LDH as illustrative examples of electrocatalyst materials in energy conversion. Furthermore, microbial fuel cell configuration has been tested.

Section snippets

Reagents

Aluminum chloride hexahydrate (AlCl3·6H2O), magnesium chloride hexahydrate (MgCl2·6H2O), nitric acid (HNO3), phosphate buffered saline tablet, potassium ferrocyanide trihydrate (K4Fe(CN)6·3H2O), sodium acetate (CH3COONa), sodium hydroxide (NaOH) and zinc chloride (ZnCl2) were purchased form Sigma–Aldrich. All chemical reagents were of analytical grade and used without further purification. Deionized water was employed for all the experiments.

LDH synthesis

MgAl and ZnAl LDH materials potentially intercalated

Structural characterization of MgAl and ZnAl LDHs

The X-ray diffraction patterns of prepared MgAl and ZnAl LDH are shown in Fig. 1. All diffraction patterns exhibit the characteristic reflections (003), (006), (009)(012), (015), (018), (110) and (113), corresponding to hexagonal LDH crystal structure with an R3¯m symmetry and suggesting that synthesized LDHs were crystallized with well-ordered structures. More intensive and sharper reflections of the (003) and (006) planes at low 2θ values (11−23°), and broad asymmetric reflections at higher 2θ

Conclusion

Layered double hydroxide MgAl and ZnAl materials were chemically synthesized and deposited over carbon electrode materials, and successfully tested as electrocatalysts for single chamber microbial fuel cell anodes. First, we introduced a structural and microstructural comparison between both samples, which is very meaningful for electrochemically fundamental research. Then, we showed that the dispersion of such LDH particles over carbon electrodes has a beneficial effect on the MFC performance

Conflict of interest

The authors declare no competing financial interest.

Acknowledgments

I would like to thank Dr. Martiane Cabié from “Centre Pluridisciplinaire de Microscopie Electronique et de Microanalyse (CP2M), Aix Marseille Université, 13013 Marseille, France”, for assistance with microscopy analysis. I would like to thank Dr. Soumya Elabed from “Laboratoire de Biotechnologie Microbienne, Faculté des Sciences et Techniques, 2022 Fez, Morocco”, for help with angle contact measurements. Finally, I would like to acknowledge graciously Aisha Gharsalli from “LECOM School of

References (60)

  • J. Qiu et al.

    Anionic clay modified electrodes: electron transfer mediated by electroactive nickel cobalt or manganese sites in layered double hydroxide films

    J. Electroanal. Chem.

    (1997)
  • B. Ballarin et al.

    Electrocatalytic properties of Nickel(II) hydrotalcite-tipe anionic clays: application to methanol and ethanol oxidation

    J. Electroanal. Chem.

    (1999)
  • E. Scavetta et al.

    Electrochemical characterisation of Ni/Al-X hydrotalcites and their electrocatalytic behaviour

    Electrochim. Acta

    (2002)
  • E. Scavetta et al.

    AC impedance study of a synthetic hydrotalcite-like compound modified electrode in aqueous solution

    Electrochim. Acta

    (2003)
  • K. Nejati et al.

    Electrochemical synthesis of nickel-iron lzyered double hydroxide: application as a novel modified electrode in electrocatalytic reduction of metronidazole

    Mater. Sci. Eng. C

    (2014)
  • E. Scavetta et al.

    Electrochemical characterization of electrodes modified with a Co/Al hydrotalcite-like compound

    Electrochim. Acta

    (2005)
  • E. Scavetta et al.

    Electrochemical sensors based on electrodes modified with synthetic hydrotalcites

    Electrochim. Acta

    (2006)
  • P. Vialat et al.

    Insights into the electrochemistry of (CoxNi(1-x))2Al-NO3 layered double hydroxides

    Electrochem. Acta

    (2013)
  • Z. Feng et al.

    The application of Co-Al-hydrotalcite as a novel additive of positive material for nickel-metal hybride secondary cells

    J. Power Sources

    (2014)
  • A. Zebda et al.

    Hybrid layered double hydroxides-polypyrrole composites for construction of glucose/O2 biofuel cell

    Electrochim. Acta

    (2011)
  • S.N. Ding et al.

    Laccase electrodes based on the combination of the single-walled carbon nanotubes and redox layered double hydroxides: towards the development of biocathode for biofuel cells

    J. Power Sources

    (2010)
  • M.A. Djebbi et al.

    Abdesslem Ben Haj Amara, Novel Biohybrids of layered double hydroxide and lactate dehydrogenase enzyme: synthesis, characterization and catalytic activity studies

    J. Mol. Struct.

    (2016)
  • M.A. Djebbi et al.

    Abdesslem Ben Haj Amara, Preparation and optimization of a drug delivery system based on berberine chloride-immobilized MgAl hydrotalcite

    Int. J. Pharm.

    (2016)
  • X.X. Shi et al.

    Application of nitrogen-doped carbon powders as low-cost and durable cathodic catalyst to air-cathode microbial fuel cells

    Bioresour. Technol.

    (2012)
  • P. Teixeira et al.

    Interfacial interactions between nitrifying bactéria and mineral carriers in aqueous media determined by contact angle measurements and thin layer wcking

    Colloids Surf. B

    (1998)
  • L. Xie et al.

    CoxNi1-x double hydroxide nanoparticles with ultrahigh specific capacitance as supercapacitor electrode materials

    Electrochim. Acta

    (2012)
  • S. Kikkawa et al.

    Ferrocyanide anion bearing Mg, Al hydroxide

    Mater. Res. Bull.

    (1982)
  • D. Mondal et al.

    Improved reversibility of color changes in electrochromic Ni-Al LDH layered double hydroxide films in presence of electroactive anions

    J. Electroanal. Chem.

    (2012)
  • B.E. Logan et al.

    Microbial fuel cell: methodology and technology

    Environ. Sci. Technol.

    (2006)
  • B. Min et al.

    Continuous electricity generation from domestic waste water and organic substrates in a flat plate microbial fuel cell

    Environ. Sci. Technol.

    (2004)
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