Direct sunlight-driven degradation of 2-chlorophenol catalyzed by kaolinite-supported ZnO
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Commercial and laboratory-prepared ZnO nanoparticles are assessed here as a photocatalyst in photodegradation of aqueous 2-chlorophenol under direct sunlight. Kaolinite is used as a support for ZnO to enable its recovery after reuse. The composite ZnO/kaolinite is prepared by growing ZnO nanoparticles directly on kaolinite surface and is characterized by a number of methods such as electronic absorption spectra, photoluminescence spectra, X-ray diffraction and scanning electron microscopy. All ZnO systems (commercial, synthetic and supported) exhibit the wurtzite phase. The composite ZnO/kaolinite shows higher photocatalysis efficiency in 2-chlorophenol degradation over both commercial and synthetic ZnO powders. The composite ZnO/kaolinite is also easier to recover and reuse, showing no observable loss in its catalyst efficiency even after five cycles. These features highlight the merit of using composite ZnO/kaolinite as photocatalyst in water purification with direct sunlight for the first time. All catalyst systems are more efficient in basic media (pH ~ 8.5) than in neutral and acidic media, as rationalized by the point of zero charge concepts here. Moreover, the composite ZnO/kaolinite shows enhanced catalytic efficiency in 2-chlorophenol photodegradation in a wider pH range, compared to other counterparts, which shows another added value.
KeywordsPhotodegradation ZnO photocatalyst Kaolinite support 2-Chlorophenol Surface charge
The authors wish to thank An-Najah N. University for financial support. Assistance from technical staff of the Department of Chemistry is acknowledged. The authors also wish to acknowledge help from United Arab Emirates University for SEM and XRD measurements.
The results shown here are partly based on T. Zorba thesis (supervised by H. S. Hilal and A. H. Zyoud). A. H. Zyoud performed extra needed experiments. S. Zyoud, N. Qamhiya and A-R. Hajamohideen performed SEM, EDX and additional XRD measurements. Sh. Zyoud helped in TOC analysis. M. Helal helped in reviewing the literature and formulating the study. A. H. Zyoud and H. S. Hilal wrote up the manuscript. All authors read and approved the manuscript.
Compliance with Ethical Standards
Conflicts of interest
The authors declare that there are no conflicts of interest regarding the publication of this paper.
- Akhtar MJ, Ahamed M, Kumar S, Khan MM, Ahmad J, Alrokayan SA (2012) Zinc oxide nanoparticles selectively induce apoptosis in human cancer cells through reactive oxygen species. Int J Nanomed 7:845Google Scholar
- Bazrafshan E, Mostafapour FK, Faridi H, Zazouli MA (2012) Application of Moringa peregrina seed extract as a natural coagulant for phenol removal from aqueous solutions. Afr J Biotech 11:16758–16766Google Scholar
- Cardenas-Peña AM, Ibanez JG, Vasquez-Medrano R (2012) Determination of the point of zero charge for electrocoagulation precipitates from an iron anode. Int J Electrochem Sci 7:6142–6153Google Scholar
- Michaleowicz J (2005) The occurrence of chlorophenols, chlorocatechols and chlorinated methoxyphenols in drinking water of the largest cities in Poland. Pol J Environ Stud 14:327–333Google Scholar
- Michałowicz J, Duda W (2007) Phenols-Sources and toxicity. Pol J Environ Stud 16:347Google Scholar
- Misra AJ, Das S, Rahman AH, Das B, Jayabalan R, Behera SK, Suar M, Tamhankar AJ, Mishra A, Lundborg CS (2018) Doped ZnO nanoparticles impregnated on Kaolinite (Clay): a reusable nanocomposite for photocatalytic disinfection of multidrug resistant Enterobacter sp. under visible light. J Colloid Interface Sci 530:610–623CrossRefGoogle Scholar
- Pang X-Y (2010) Adsorption capacity and mechanism of expanded graphite for polyethylene glycol and oils. J Chem 7:1258–1265Google Scholar
- Rappoport Z (2004) The chemistry of phenols. Wiley, HobokenGoogle Scholar
- Zyoud AH, Hilal HS (2008) Silica-supported CdS-sensitized TiO2 particles in photo-driven water purification: assessment of efficiency, stability and recovery future perspectives, Chapter in a book, Water Purification, Novascience Pub, New York (in press, 2008)Google Scholar
- Zyoud A, Hilal H (2013) Curcumin-sensitized anatase TiO2 nanoparticles for photodegradation of methyl orange with solar radiation. In: 1st international conference and exhibition on the applications of information technology to renewable energy processes and systems (IT-DREPS). IEEE, pp 31–36Google Scholar
- Zyoud A, Dwikat M, Al-Shakhshir S, Ateeq S, Shteiwi J, Zu’bi A, Helal MH, Campet G, Park D, Kwon H (2016) Natural dye-sensitized ZnO nano-particles as photo-catalysts in complete degradation of E. coli bacteria and their organic content. J Photochem Photobiol A: Chem 328:207–216CrossRefGoogle Scholar