High-efficiency electrochemical degradation of phenol in aqueous solutions using Ni-PPy and Cu-PPy composite materials

https://doi.org/10.1016/j.jhazmat.2021.126986Get rights and content

Highlights

  • The crystalline polypyrrole powder from an organic medium was synthesized.

  • Ni-PPy and Cu-PPy electrodes provided new ideas for degradation of phenol.

  • The direct effect of the nature of the anode materials on oxidation was demonstrated.

  • The optimum value of current density was achieved at 0.58 mA cm−2.

  • Cu-PPy electrode is efficient and economical in treating real-scale phenol wastewater.

Abstract

Conductive crystalline polypyrrole (Cryst-PPy), Nickel-polypyrrole (Ni-PPy), and copper- polypyrole (Cu-PPy) hybrid materials were prepared using a chemical polymerization method in an aqueous solution. Part I was focused on the Chemical synthesis of Cryst-PPy powder from an organic medium. Cryst-PPy powder was successfully synthesized by chemical route from an organic medium of acetonitrile with polyethylene oxide as a stabilizing agent and oxidizing agent like potassium peroxydisulfate. The morphological study was showed the presence of spherical nanoparticles and cubic microparticles giving rise to a denser structure of PPy. In the second part, the based electrodes composites were examined in the oxidation of phenol by an electrochemical process in an alkaline medium. To follow the yield of phenol degradation at the alkaline solution, UV–visible analysis was performed at the following operating conditions: current density of 0.58 mA cm−2, phenol initial concentration of 0.150 M and for 3 h processing; the rate of phenol elimination was 56%, 38% and 28% for Cu-PPy, Ni-PPy, and pure PPy electrodes respectively. Thus, can be found that the doped Cu-PPy electrodes electrode is a new material with high electrochemical oxidation ability for phenol degradation in aqueous solutions.

Graphical Abstract

High-efficiency electrochemical degradation of phenol in aqueous solutions using PPy-based composite.

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Introduction

Water is considered a unique source of life and covers 70% of the Earth’s surface. Due to the lack of freshwater resources and remarkable increase in population and the massive expansion of urban areas involved in recent years, the improvement of new methods to increase the fraction of freshwater is needed (Wang et al., 2021a). Organic pollutants have emerged in the water system from various industrial wastes which are mainly recalcitrant stable-chemical compounds with toxicity relatively high (Doan et al., 2021).

Phenolic compounds are one of the most dangerous organic contaminations in the water systems. The presence of phenolic compounds in water is due to the wastes of many industrial effluents such as petroleum sources, pesticides and herbicides, textiles industries, pharmaceuticals by-products, and detergent (Moradi et al., 2021). Biodegradation of phenolic compounds is very limited due to their recalcitrant nature, stability, and high toxicity, thus their treatment in-situ is primordial (Muthu Kumara Pandian et al., 2021, Sridar et al., 2018). The treatment with conventional processes such as flocculation, sedimentation, etc. is not sufficient for ensuring of good quality of water (Vasseghian et al., 2021, Smaali et al., 2021). Nowadays; electrochemical treatment is considered as one the most efficient low-cost technique, which is based on electrochemical-coagulation, electrochemical-flocculation, electrochemical flotation, electrochemical-deposition, electrochemical oxidation, electrochemical-disinfection, etc. (Wang et al., 2021b).

Electrochemical oxidation has earlier been promising in the purification of wastewater charged the phenolic compounds (Min et al., 2020, Gui et al., 2020, Zhu et al., 2010). The electro-oxidation processes as a cost-effective technology (Norra and Radjenovic, 2021, Mansoorianfar et al., 2020) are suitable for the treatment of aromatic pollutants, and they could be used for both a pre-treatment to facilitate biodegradability or even for complete mineralization into water and carbon dioxide of organic pollutants (Jiang et al., 2021). No doubt that the electrode material is an important part of the electrocatalytic oxidation (Hwa et al., 2020), it should be noted that the electrode is efficient material for organic pollutant elimination and they are extremely electrochemically stable and inexpensive (Droguett et al., 2020).

Electrochemical sensors based on polymer nanocomposites such as polypyrole (PPy), polyaniline, or polythiophene that have been doped with various transition metals have been successfully used in various studies to degrade organic pollutants (Belgherbi et al., 2020, Lakhdari et al., 2021b) due to excellent catalytic and electrocatalytic properties (Lakhdari et al., 2021a, Sarojini et al., 2021).

The PPy polymer is the most utilization among conducting polymers (CPs) due to their remarkable environmental and thermal stability and, as well as to their excellent intrinsic conductivity, facile route of synthesis, and the formation of co-polymers providing optimal mechanical properties. Besides, PPy is considered an excellent material for wastewater treatment due to its physical properties as well as its good intrinsic properties (Prunet et al., 2021, Ramanavicius et al., 2021). CPs could be synthesized by various routes such as chemical, photochemical and electrochemical polymerization, solvothermal, electrospinning, self-assembly, hydrothermal, template-assisted, vapor phase synthesis, the solid-state method, and plasma polymerization (Rahaman et al., 2018, Namsheer and Rout, 2021).

CPs synthesis is mainly based on two methods that are most used including chemical and electrochemical polymerization (Alizadeh and Amjadi, 2011, Ilic et al., 2020). The chemical synthesis represents the most methodical of CPs preparing, which is conducted even in absence of electrodes and this method can provide CPs in the form of powder form or very thick films (Qian et al., 2020).

PPy like polyaniline can be obtained by both chemical or electrochemical methods, besides, PPy are non-toxic materials and biocompatible, which makes them a large alternative for biological systems (Akl et al., 2003).

PPy is typically synthesized using the oxidation of a black powdery pyrrole monomer with hydrogen peroxide. The PPy in non-crystalline form has a constant conductivity of 10−5 s m−1, and this is in the case of its doping with bromine or iodine providing halogenic electron acceptors, and it acts as amorphous (Müller et al., 2011). Therefore, the crystallinity of the bulk PPy is 15%, and the crystalline region is monoclinic (Benhaddad et al., 2013).

Many previous works described the chemical synthesis of PPy using a variety of oxidants as well as ferric chloride (Benhaddad et al., 2011), ammonium persulfate (Varma et al., 2012), manganese dioxide (Mileva et al., 2018), and a diversity of stabilizing agents as dodecylbenzene sulfonic acid (Zhang et al., 2020).

Besides, many electrodes of metallic-based nanoparticles (MNPs) such as palladium (Shi and Diao, 2011), silver (Nantaphol et al., 2015), gold (Lin et al., 2013), etc. have been recently reported. The high cost and the limited availability of some of these materials can inflict limitations on the development of sensors. To address these limitations, other MNPs such as Ni (NPs) (Chen et al., 2014) and Cu (NPs) (Sankar et al., 2014) have appeared as alternative materials for applications of catalysis and medicine (Guisbiers et al., 2014). Cu NPs have been used in electrochemical sensors for dopamine (Fredj et al., 2020), amino acids (Carvalho et al., 2013), and ascorbic acid so far (Fredj et al., 2020); due to their extraordinary catalytic activities, relatively inexpensive, and high conductivities.

Polymer crystallinity is a very significant property affecting all mechanical strength, thermal, and opacity features of polymers (Ameh, 2019). In material processing, the crystallinity measurements prepare critical information for both quality control and materials research (Liu et al., 2019). Crystallinity in polymers in compounds with low molecular weight is different to those only partial, and the chaining of polymers are not aligned with each other over their entire length, and the alignment is limited to small crystallite areas (Saheeda and Jayaleksmi, 2020).

Polymers semi-crystalline combines two major properties (crystalline and amorphous) which make them very interesting due to the strength of crystalline and amorphous regions, (Anuma et al., 2021). Thus, increasing in crystallinity of polymer could lead to an increase in the secondary bonding allowing good stiffness (elastic modulus) and strength of the polymer (Park et al., 2016). Few works studied the synthesis of highly crystalline regions in PPy films which are prepared from camphor sulfonic acid (CSA), so far (Bora and Dolui, 2012). In the present work, the chemical synthesis strategy used is novel where in has been attempted to synthesize highly crystalline PPy powder from an organic medium (Park et al., 2016). Besides, to increase conductivity and current density, various electrolytes such as Na2SO4, H2SO4, NaCl, and their mixtures were used for electrochemical degradation of phenol (Tawabini et al., 2020). However, very few investigators have used NaOH as a supporting electrolyte.

The purpose of the current study was to assay the beneficial impact of Ni and Cu particles on PPy-based electrode materials in the electro-oxidation of phenol. Moreover, the electro-oxidation of phenol using Cryst-PPy, Ni-PPy, and Cu-PPy composite electrodes in alkaline medium has been investigated by the methods of cyclic voltammetry as well as the phenol degradation tests were evaluated by UV–Visible spectra techniques.

Section snippets

Reagents

Pyrrole (Py) (CAS: 109-97-7) was provided from Alfa Aesar Company (France) and was kept at 4 °C in the dark and can be utilized without any further purification required. Sulfuric acid (CAS: 7664-93-9, chemical formula: H2SO4), copper sulfate (CAS: 7758-98-7, chemical formula: CuSO4.8H2O) nickel sulfate (CAS: 7786-81-4, chemical formula: NiSO4.6H2O), hydrochloric acid (CAS: 7647-01-0, chemical formula: HCl), sodium hydroxide (CAS: 1310-73-2, chemical formula: NaOH), and acetonitrile (CAS:

SEM and XRD analysis

Fig. 1a presents the X-ray diffraction pattern of PPy synthesized from an organic medium. As can be seen, the prominent peaks at about 23.8° and 26.5° denoted the d- spacing values 3.82 and 3.45 A0, respectively. The obtained values of (d) show the distance of interlayer between pyrrole, pyrrole ring, the dopant, and the face-to-face stacking distance, respectively (Carrasco et al., 2006).

However, it was reported in the literature that the XRD pattern relative to PPy powder synthesized from an

Conclusion

The Cryst-PPy, Ni-PPy, and Cu-PPy hybrid materials were successfully synthesized using the chemical route from an organic medium. The characterization by FTIR, XRD, SEM, TGA-DTA, and CV techniques was confirmed the high crystallinity structure of PPy powder with spherical nanoparticles and cubic microparticles this smoother and denser morphology would be more conductive and facilitating the transport of charge. Electrochemical oxidation of phenol was studied in alkaline solution using the

CRediT authorship contribution statement

Lamria Seid: Supervision, Conceptualization, Data curation, Formal analysis, Software, Methodology, Validation, Writing - original draft, Writing – review & editing. Delloula Lakhdari: Supervision, Conceptualization, Data curation, Formal analysis, Software, Methodology, Validation, Writing – original draft, Writing – review & editing. Mohammed Berkani: Adviser, Formal analysis, Software, Methodology, Validation, Writing – original draft, Writing – review & editing. Ouafia Belgherbi: Advisor,

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The authors thank the Algeria Directorate General for Scientific Research and Technological Development (DGRSDT) for grants that made this research work possible.

References (69)

  • D. Chen et al.

    Fabrication of polypyrrole/β-MnO2 modified graphite felt anode for enhancing recalcitrant phenol degradation in a bioelectrochemical system

    Electrochim. Acta

    (2017)
  • H. Chen et al.

    Molecularly imprinted electrochemical sensor based on nickel nanoparticles-graphene nanocomposites modified electrode for determination of tetrabromobisphenol A

    Electrochim. Acta

    (2014)
  • A. De et al.

    Heavy ion irradiation on conducting polypyrrole and ZrO2–polypyrrole nanocomposites

    Synth. Metals

    (2004)
  • V.-D. Doan et al.

    Cu2O/Fe3O4/MIL-101(Fe) nanocomposite as a highly efficient and recyclable visible-light-driven catalyst for degradation of ciprofloxacin

    Environ. Res.

    (2021)
  • L. Gui et al.

    Preparation and characterization of ZnO/PEG-Co (II)-PbO2 nanocomposite electrode and an investigation of the electrocatalytic degradation of phenol

    J. Hazard. Mater.

    (2020)
  • R. Hu et al.

    Efficient removal of phenol and aniline from aqueous solutions using graphene oxide/polypyrrole composites

    J. Mol. Liq.

    (2015)
  • Y. Jiang et al.

    Anodic oxidation for the degradation of organic pollutants: anode materials, operating conditions and mechanisms. A mini review

    Electrochem. Commun.

    (2021)
  • D. Lakhdari et al.

    A novel non-enzymatic glucose sensor based on NiFe(NPs)–polyaniline hybrid materials

    Food Chem. Toxicol.

    (2021)
  • X. Lin et al.

    Glassy carbon electrodes modified with gold nanoparticles for the simultaneous determination of three food antioxidants

    Anal. Chim. Acta

    (2013)
  • M. Mansoorianfar et al.

    Scalable fabrication of tunable titanium nanotubes via sonoelectrochemical process for biomedical applications

    Ultrason. Sonochem.

    (2020)
  • S.T. McBeath et al.

    Simultaneous electrochemical oxidation and ferrate generation for the treatment of atrazine: a novel process for water treatment applications

    J. Hazard. Mater.

    (2021)
  • S.-J. Min et al.

    Role of carbon fiber electrodes and carbonate electrolytes in electrochemical phenol oxidation

    J. Hazard. Mater.

    (2020)
  • M. Moradi et al.

    Ultrasound‐assisted synthesis of FeTiO3/GO nanocomposite for photocatalytic degradation of phenol under visible light irradiation

    Sep. Purif. Technol.

    (2021)
  • D. Müller et al.

    Chemical in situ polymerization of polypyrrole on bacterial cellulose nanofibers

    Synth. Metals

    (2011)
  • A. Muthu Kumara Pandian et al.

    Anaerobic mixed consortium (AMC) mediated enhanced biosynthesis of silver nano particles (AgNPs) and its application for the removal of phenol

    J. Hazard. Mater.

    (2021)
  • S. Nantaphol et al.

    Sensitive and selective electrochemical sensor using silver nanoparticles modified glassy carbon electrode for determination of cholesterol in bovine serum

    Sens. Actuators B Chem.

    (2015)
  • G.-F. Norra et al.

    Removal of persistent organic contaminants from wastewater using a hybrid electrochemical-granular activated carbon (GAC) system

    J. Hazard. Mater.

    (2021)
  • M. Omastová et al.

    Polypyrrole and polyaniline prepared with cerium (IV) sulfate oxidant

    Synth. Metals

    (2010)
  • G. Prunet et al.

    A review on conductive polymers and their hybrids for flexible and wearable thermoelectric applications

    Mater. Today Phys.

    (2021)
  • J. Qian et al.

    Development of highly efficient chemosensors for Cu2+ and N2H4 detection based on 2D polyaniline derivatives by template-free chemical polymerization method

    J. Hazard. Mater.

    (2020)
  • M. Rashid et al.

    Zirconium (IV) phosphosulphosalicylate-based ion selective membrane electrode for potentiometric determination of Pb (II) ions

    Arab. J. Chem.

    (2019)
  • P. Saheeda et al.

    Liquid/liquid interfacial polymerization as an effective synthesis approach for polypyrrole/MWCNTs nanocomposite with impressive nonlinear optical properties

    Opt. Mater.

    (2020)
  • R. Sankar et al.

    Anticancer activity of Ficus religiosa engineered copper oxide nanoparticles

    Mater. Sci. Eng. C

    (2014)
  • G. Sarojini et al.

    Facile synthesis and characterization of polypyrrole - iron oxide – seaweed (PPy-Fe3O4-SW) nanocomposite and its exploration for adsorptive removal of Pb(II) from heavy metal bearing water

    Chemosphere

    (2021)
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