Electrochemical generation of H2O2 using immobilized carbon nanotubes on graphite electrode fed with air: Investigation of operational parameters

Khataee, Alireza; Safarpour, Mahdie; Zarei, Mahmoud; Aber, Soheil

doi:10.1016/j.jelechem.2011.05.002

Cited by 163 publications

(55 citation statements)

References 53 publications

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“…S4 in the supplemental material]). This is more negative than the theoretical dissolved O 2 reduction potential at a neutral pH of ϳ0.10 (43) and previously reported values of Ϫ0.5 to Ϫ0.8 V measured against 1 M Ag/AgCl (44), likely to due to a higher overpotential from the Nafion coating hindering electron transfer. The maximum H 2 O 2 concentration was ϳ0.01 mM after 5 min of electrolysis using saturated oxygen in the absence of bacteria and broth; thus, under the bacterial incubation conditions, the cumulative H 2 O 2 generation will be less than 0.07 mM in 3 h. If one also considers possible cathodic H 2 O 2 reduction pathways to the hydroxyl radical and water as well as H 2 O 2 loss via reaction with the broth components, the final H 2 O 2 concentration will be lower than the minimal concentrations observed to be toxic to bacteria (Ն0.15 mM) (45).…”

Section: Materials Characterizationcontrasting

confidence: 56%

Semiquantitative Performance and Mechanism Evaluation of Carbon Nanomaterials as Cathode Coatings for Microbial Fouling Reduction

Zhang

Nghiem

Silverberg

et al. 2015

Appl Environ Microbiol

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In this study, we examine bacterial attachment and survival on a titanium (Ti) cathode coated with various carbon nanomaterials (CNM): pristine carbon nanotubes (CNT), oxidized carbon nanotubes (O-CNT), oxidized-annealed carbon nanotubes (OA-CNT), carbon black (CB), and reduced graphene oxide (rGO). The carbon nanomaterials were dispersed in an isopropyl alcoholNafion solution and were then used to dip-coat a Ti substrate. Pseudomonas fluorescens was selected as the representative bacterium for environmental biofouling. Experiments in the absence of an electric potential indicate that increased nanoscale surface roughness and decreased hydrophobicity of the CNM coating decreased bacterial adhesion. The loss of bacterial viability on the noncharged CNM coatings ranged from 22% for CB to 67% for OA-CNT and was dependent on the CNM dimensions and surface chemistry. For electrochemical experiments, the total density and percentage of inactivation of the adherent bacteria were analyzed semiquantitatively as functions of electrode potential, current density, and hydrogen peroxide generation. Electrode potential and hydrogen peroxide generation were the dominant factors with regard to short-term (3-h) bacterial attachment and inactivation, respectively. Extended-time electrochemical experiments (12 h) indicated that in all cases, the density of total deposited bacteria increased almost linearly with time and that the rate of bacterial adhesion was decreased 8-to 10-fold when an electric potential was applied. In summary, this study provides a fundamental rationale for the selection of CNM as cathode coatings and electric potential to reduce microbial fouling. Biofilm formation is ubiquitous in aquatic environments and is undesirable for industrial systems, such as heat exchangers and ship hulls (1), as well as for engineered environmental systems, such as membrane filters (2) and water distribution pipelines. A critical initial stage of biofouling involves microorganism adhesion and formation of the primary slime layer that allows for continued biofilm development (3, 4). Thus, if initial microorganism adhesion is reduced, continued biofilm development may be slowed as well.Continuous research efforts have been devoted to microbial fouling control, from the development of antimicrobial surfaces (5) to the disturbance of bacterial biofilm ecology by quorum sensing (6, 7). With regard to antimicrobial surfaces, the interfacial energy between a surface and water has been identified as a key factor in microbial adhesion, and hydrophilic surfaces generally hinder protein adsorption and, in turn, reduce biofouling (8). A highly charged cationic surface has also been demonstrated to kill bacteria and reduce fouling (9). However, since microbes have a complex and species-dependent surface chemistry, a permanently modified surface will not reduce biofouling for all microbes, and decreased antifouling performance is often observed in complex environments. One solution may be active biofouling reduction that can be tuned in situ ...

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Section: Materials Characterizationcontrasting

confidence: 56%

Semiquantitative Performance and Mechanism Evaluation of Carbon Nanomaterials as Cathode Coatings for Microbial Fouling Reduction

Zhang

Nghiem

Silverberg

et al. 2015

Appl Environ Microbiol

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“…In B system, in situ generation of H 2 O 2 on ACF cathode occurred via the following reaction (4) [31]:…”

Section: Comparison Of Three Systems For Cyanide Removalmentioning

confidence: 99%

Cyanide oxidation by singlet oxygen generated via reaction between H 2 O 2 from cathodic reduction and OCl − from anodic oxidation

Tian¹,

Zeng

et al. 2016

Journal of Colloid and Interface Science

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“…However, compared with CB and CNTs, AC was an inefficient GDC material for O 2 reduction to generate H 2 O 2 (Soltani et al 2012), which can react with sparged O 3 to produce ·OH. Thus, the above phenomena can be explained by the fact that CNTs have a great number of mesoporous pores and large accessible surface area (Khataee et al 2011), so that both O 2 and O 3 can be reduced easily on the cathode surface to generate more ·OH. Since the oxidation power of ozone-electrolysis system is mainly related to the produced intermediate reactive oxygen species, the cathode materials which have high ·OH production ability are essential for the effective degradation of pollutants.…”

Section: Resultsmentioning

confidence: 99%

“…Heterogeneous catalytic ozonation using CNTs can overcome the drawbacks of ozonation alone, such as selective reactivation and by-product formation (Fan et al 2014). As carbon materials, CNTs also exhibit excellent capability for electrogeneration of H 2 O 2 (Khataee et al 2011;Vahid and Khataee 2013). Thus, CNTs may be suitable cathode materials for the ozone-electrolysis process.…”

Section: Introductionmentioning

confidence: 99%

Enhanced hydroxyl radical generation in the combined ozonation and electrolysis process using carbon nanotubes containing gas diffusion cathode

Zhang

et al. 2015

Environ Sci Pollut Res

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Combination of ozone together with electrolysis (ozone-electrolysis) is a promising wastewater treatment technology. This work investigated the potential use of carbon nanotube (CNT)-based gas diffusion cathode (GDC) for ozone-electrolysis process employing hydroxyl radicals (·OH) production as an indicator. Compared with conventional active carbon (AC)-polytetrafluoroethylene (PTFE) and carbon black (CB)-PTFE cathodes, the production of ·OH in the coupled process was improved using CNTs-PTFE GDC. Appropriate addition of acetylene black (AB) and pore-forming agent Na2SO4 could enhance the efficiency of CNTs-PTFE GDC. The optimum GDC composition was obtained by response surface methodology (RSM) analysis and was determined as CNTs 31.2 wt%, PTFE 60.6 wt%, AB 3.5 wt%, and Na2SO4 4.7 wt%. Moreover, the optimized CNT-based GDC exhibited much more effective than traditional Ti and graphite cathodes in Acid Orange 7 (AO7) mineralization and possessed the desirable stability without performance decay after ten times reaction. The comparison tests revealed that peroxone reaction was the main pathway of ·OH production in the present system, and cathodic reduction of ozone could significantly promote ·OH generation. These results suggested that application of CNT-based GDC offers considerable advantages in ozone-electrolysis of organic wastewater.

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Electrochemical generation of H2O2 using immobilized carbon nanotubes on graphite electrode fed with air: Investigation of operational parameters

Cited by 163 publications

References 53 publications

Semiquantitative Performance and Mechanism Evaluation of Carbon Nanomaterials as Cathode Coatings for Microbial Fouling Reduction

Semiquantitative Performance and Mechanism Evaluation of Carbon Nanomaterials as Cathode Coatings for Microbial Fouling Reduction

Cyanide oxidation by singlet oxygen generated via reaction between H 2 O 2 from cathodic reduction and OCl − from anodic oxidation

Enhanced hydroxyl radical generation in the combined ozonation and electrolysis process using carbon nanotubes containing gas diffusion cathode

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