Fabrication and characterization of PbO2 electrode modified with polyvinylidene fluoride (PVDF)

doi:10.1016/j.apsusc.2016.07.123

Applied Surface Science

Volume 389, 15 December 2016, Pages 278-286

https://doi.org/10.1016/j.apsusc.2016.07.123 Get rights and content

Highlights

•
PVDF composites are firstly used to modify PbO₂ electrode.
•
PVDF addition can enhance the electrocatalytic activity of PbO₂ electrode.
•
PVDF addition can enhance the stability of PbO₂ electrode significantly.
•
The optimum doping amount of PVDF was between 1 g L⁻¹–2 g L⁻¹.

Abstract

A novel PbO₂ electrode with a high oxygen evolution potential (OEP) and long service life was successfully fabricated by doping polyvinyl fluoride (PVDF) (marked as PbO₂-PVDF) through co-deposition method. The morphology (SEM), elemental analysis (EDX), hydrophobic property (contact angle), crystalline structure (XRD), chemical state (XPS), electrochemical performances (Lsv and EIS) and stability (accelerated life test) were characterized. The results showed that PVDF doping could improve the film morphology, increase oxygen evolution potential (OEP) and reduce the electrode film impedance. In addition, the proportion of adsorbed hydroxyl oxygen (O_ad) on the electrode also increased. During the electrochemical oxidation process, the PbO₂-PVDF(2.0) electrode showed the best performance on degradation of phenol due to the highest removal rate, lowest energy consumption and minimum Pb dissolution, which could be attributed to its hydrophobic surface, high oxygen evolution potential (OEP) and strong capability of HO radical dot generation. Furthermore, the stability of the electrodes were greatly improved after PVDF modification. PbO₂-PVDF(1.0) electrode showed the longest service life (501 h), which was more than 4 times longer than PbO₂ electrode (118.5 h).

Introduction

Electrochemical oxidation treatment (EOT), an attractive wastewater treatment technology, has been widely applied in wastewater treatment due to its high efficiency, mild condition, easy operation and environmental friendliness [1], [2]. Anode as the core component is particularly important in the electrochemical oxidation process [3], [4]. Therefore, it is essential to develop an excellent electrode with high catalytic activity and stability at low cost [5].

So far, various types of electrodes have been investigated. Such as graphite [6], Pt [7], boron-doped diamond (BDD) [8] and dimensionally stable anodes (Ti/IrO₂ [9], Ti/RuO₂ [10], Ti/MnO₂ [11], Ti/SnO₂ [12] and Ti/PbO₂ [13], etc.). Among these electrodes, Ti/PbO₂ was regarded as the most promising electrode and has been successfully used in EOT process due to its high electrocatalytic activity, high chemical stability, ease of synthesis as well as low cost [14], [15], [16]. However, due to its relatively large interface resistance, the surface coating would peel off easily, leading to the leakage of Pb elements [5], [17]. In addition, the electrocatalytic activity of Ti/PbO₂ electrode is still lower compared with BDD and Ti/SnO₂ electrodes [8], [18]. Therefore, the stability and electrocatalytic activity of the Ti/PbO₂ electrode still need further improvement. To solve the problem, many efforts have been devoted, including modifying substrate [19], [20], introducing the middle layer [21], [22] and doping elements [15], [23], [24], [25]. Meanwhile, some polymers materials, such as polyvinylpyrrolidone (PVP) [26], Polypyrrole (PPy) [27], fluorine resin [28] and polytetrafluoroethylene (PTFE) [29] were also adopted to enhance the electrochemical oxidation ability and stability of PbO₂ electrode. The results show that the introduction of polymers materials could effectively improve the properties of PbO₂ electrode.

Polyvinyl fluoride (PVDF) is an important and excellent polymer, possessing many excellent properties such as excellent chemical corrosion resistance, flexibility, high abrasion resistance, hydrophobicity and low cost, which has been extensively investigated and applied in many industrial fields [30], [31], [32]. Therefore, the PbO₂ electrode modified with PVDF may be promising and interesting. However, the study of electrodes modified with PVDF is rarely reported. Zhao et al. [5] has prepared a hydrophobic PbO₂ electrode with high OEP and excellent electrochemical oxidation performance by doping with fluorine resin. The literature points out that the electrode with a hydrophobic surface is more favorable for improving the utilization rate of HO radical dot radical. In addition, F doping could greatly enhance the service life of PbO₂ electrode.

Therefore, in this work, PVDF composite doped PbO₂ electrode was successfully developed to form a hydrophobic PbO₂-PVDF electrode with excellent electrocatalytic activity and stability. The morphology, hydrophobic property, crystalline structure, chemical state, electrochemical performances and stability were characterized. The capability of HO radical dot generation on the electrodes were also evaluated. One of the widely used crude material, phenol, was chosen as the model pollutant for electrochemical oxidation in order to evaluate its electrochemical ability. Besides, Pb element leaching of PbO₂ electrodes was also studied during electrolysis process to evaluate the safety.

Section snippets

Chemicals and reagents

All chemicals used in experiment were obtained from Sinopharm Chemical Reagent Xi’an Co., Ltd and were of analytical grade without further purification. The aqueous solutions were deionized water (18 MΩ cm). PVDF composite (size 6.5 μm, French arkoma HSV900) were purchased from Shanghai Shi Quan Industrial Co., Ltd.

Electrode preparation

Ti plates (Purity >99.6%, BaoTi Ltd., China) with a dimension of 3 cm × 3 cm × 0.5 mm were used as the electrode substrate. The pre-treatment of Ti plate and introduction of inner Sb–SnO₂

Surface morphology and hydrophobic property of the electrodes

Fig. 1 shows the SEM images of the PbO₂ electrodes prepared with different PVDF doping amounts. From Fig. 1a, it could be observed that the PbO₂ electrode was rough with typical pyramidal shapes on the surface [23]. After further observation, some damages and cracks were found on the surface (Inside the circle). This morphology could cause the decrease of the stability of the electrodes in the electrolysis, because electrolyte may permeate the Ti substrate through the damages and cracks easily,

Conclusions

A novel PbO₂ electrode with a high oxygen evolution potential (OEP) and long service life was modified by PVDF composites through co-deposition method and used for electrochemical degradation of phenol. PVDF modification could improve the film morphology, increase OEP and reduce the electrode film impedance. During the electrochemical oxidation process, the electrochemical oxidation of phenol followed pseudo-first-order kinetics and the PbO₂-PVDF(2.0) electrode showed the best performance on

Acknowledgement

This work was supported by the National Natural Science Foundation of China (Grant No. 21507104).

References (46)

E. Brillas et al.
Decontamination of wastewaters containing synthetic organic dyes by electrochemical methods. An updated review
Appl. Catal. B: Environ.
(2015)
J. Chen et al.
Electrochemical degradation of chloramphenicol with a novel Al doped PbO2 electrode: performance, kinetics and degradation mechanism
Electrochim. Acta
(2015)
Y.H. Cui et al.
Electrochemical degradation of bisphenol A on different anodes
Water Res.
(2009)
B. Cercado-Quezada et al.
Electrochemical micro-structuring of graphite felt electrodes for accelerated formation of electroactive biofilms on microbial anodes
Electrochem. Commun.
(2011)
M.G. Tavares et al.
Electrochemical oxidation of methyl red using Ti/Ru0.3Ti0.7O2 and Ti/Pt anodes
Chem. Eng. J.
(2012)
L.S. Andrade et al.
On the performances of lead dioxide and boron-doped diamond electrodes in the anodic oxidation of simulated wastewater containing the Reactive Orange 16 dye
Electrochim. Acta
(2009)
M. Li et al.
Electrochemical degradation of phenol using electrodes of Ti/RuO2-Pt and Ti/IrO2-Pt
J. Hazard. Mater.
(2009)
J.L. Fernández et al.
Kinetic study of the chlorine electrode reaction on Ti/RuO2 through the polarisation resistance part III: proposal of a reaction mechanism
Electrochim. Acta
(2002)
H. Lin et al.
Electrochemical degradation of perfluorooctanoic acid (PFOA) by Ti/SnO2-Sb, Ti/SnO2-Sb/PbO2 and Ti/SnO2-Sb/MnO2 anodes
Water Res.
(2012)
L. Xu et al.
Preparation and characterization of Ti/SnO2-Sb electrode with copper nanorods for AR 73 removal
Electrochim. Acta
(2015)

W. Zhang et al.

Preparation and characterization of lead dioxide electrode with three-dimensional porous titanium substrate for electrochemical energy storage

Electrochim. Acta

(2014)

G. Darabizad et al.

Electrodeposition of morphology- and size-tuned PbO2 nanostructures in the presence of PVP and their electrochemical studies

Mater. Chem. Phys.

(2015)

X. Hao et al.

Fabrication and characterization of PbO2 electrode modified with [Fe(CN)6]3- and its application on electrochemical degradation of alkali lignin

J. Hazard. Mater.

(2015)

A.Y. Bagastyo et al.

Electrochemical oxidation of reverse osmosis concentrate on mixed metal oxide (MMO) titanium coated electrodes

Water Res.

(2011)

H. An et al.

Fabrication and electrochemical treatment application of a microstructured TiO2-NTs/Sb–SnO2/PbO2 anode in the degradation of C.I. Reactive Blue 194 (RB 194)

Chem. Eng. J.

(2012)

D. Shao et al.

Electrochemical oxidation of lignin by two typical electrodes: ti/SbSnO2 and Ti/PbO2

Chem. Eng. J.

(2014)

X. Li et al.

Fabrication of a stable Ti/TiOxHy/Sb-SnO2 anode for aniline degradation in different electrolytes

Chem. Eng. J.

(2016)

W. Zhang et al.

Fabrication, characterization and electrocatalytic application of a lead dioxide electrode with porous titanium substrate

J. Alloys Compd.

(2015)

D. Devilliers et al.

Modified titanium electrodes: application to Ti/TiO2/PbO2 dimensionally stable anodes

Electrochim. Acta

(2010)

Q. Li et al.

Fabrication of cerium-doped lead dioxide anode with improved electrocatalytic activity and its application for removal of rhodamine B

Chem. Eng. J.

(2013)

Y. Jin et al.

Preparation and characterization of Ce and PVP co-doped PbO2 electrode for waste water treatment

J. Taiwan Inst. Chem. Eng.

(2015)

Q. Dai et al.

The application of a novel Ti/SnO2–Sb2O3/PTFE-La-Ce-β-PbO2 anode on the degradation of cationic gold yellow X-GL in sono-electrochemical oxidation system

Sep. Purif. Technol.

(2013)

L.L. Sun et al.

Achieving very high fraction of β-crystal PVDF and PVDF/CNF composites and their effect on AC conductivity and microstructure through a stretching process

Eur. Polym. J.

(2010)

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Fabrication and characterization of PbO2 electrode modified with polyvinylidene fluoride (PVDF)

Highlights

Abstract

Introduction

Section snippets

Chemicals and reagents

Electrode preparation

Surface morphology and hydrophobic property of the electrodes

Conclusions

Acknowledgement

Appl. Catal. B: Environ.

Electrochim. Acta

Water Res.

Electrochem. Commun.

Chem. Eng. J.

Electrochim. Acta

J. Hazard. Mater.

Electrochim. Acta

Water Res.

Electrochim. Acta

Electrochim. Acta

Mater. Chem. Phys.

J. Hazard. Mater.

Water Res.

Chem. Eng. J.

Chem. Eng. J.

Chem. Eng. J.

J. Alloys Compd.

Electrochim. Acta

Chem. Eng. J.

J. Taiwan Inst. Chem. Eng.

Sep. Purif. Technol.

Eur. Polym. J.

Fabrication and characterization of PbO₂ electrode modified with polyvinylidene fluoride (PVDF)