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Experimental and Computational Design of Highly Active Ce–ZrO2–GO Photocatalyst for Eosin Yellow Dye Degradation: The Role of Interface and Ce3+ Ion

  • Samuel Osei-Bonsu Oppong
  • Francis OpokuEmail author
  • William Wilson Anku
  • Ephraim Muriithi Kiarii
  • Penny Poomani GovenderEmail author
Article
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Abstract

As future photocatalyst require high activity and structural stability, the demand for high-performance photocatalyst that increases photocatalytic conversion efficiency is of significant interest. In this study, Ce–ZrO2–GO nanocomposite was fabricated by a co-precipitation technique and used for the photocatalytic degradation of eosin yellow (EY) dye under visible light irradiation. A hybrid DFT calculation was employed to analyse the electronic properties and the underlying mechanism of the observed photoactivity. The as-prepared Ce–ZrO2–GO (0.3% Ce) nanocomposite showed enhanced photodegradation of EY dye, which was about 15.98-fold higher than pure ZrO2. The enhanced performance of Ce–ZrO2–GO nanocomposite for EY dye degradation is due to the synergistic effect between the GO sheets and Ce–ZrO2. From the computational study, Ce ion could act as an electron mediator to capture the photoinduced electrons from ZrO2 to restrain the recombination rate of charge carriers. Testing with different scavengers showed that hydroxyl radicals play a major contribution to the degradation of EY dye with a pseudo first-order reaction kinetics. Total Organic Carbon analysis showed 76% mineralisation of EY dye over Ce–ZrO2–GO (0.3% Ce) nanocomposite, which is photostable and its efficiency remained almost the same after five cycles without any photocorrosion. The present study could offer an alternative approach to develop highly efficient photocatalysts for organic pollutant degradation using metal ion as a mediator to enhance charge migration, activity and structural stability of the nanocomposite.

Graphical Abstract

A series of Ce–ZrO2–GO nanocomposite were employed as a photocatalytic to degrade eosin yellow dye from wastewater. The present study offers an alternative approach to develop highly efficient photocatalysts for organic pollutant degradation using Ce ion as a mediator to enhance charge migration, activity and structural stability of the nanocomposite.

Keywords

ZrO2 Eosin yellow Hybrid density functional theory Co-precipitation technique Photodegradation 

Notes

Acknowledgements

The authors would like to acknowledge the financial contributions from the Faculty of Science: University of Johannesburg–South Africa, Centre for Nanomaterials and Science Research, Department of Applied Chemistry and the National Research Foundation (TTK14052167682). The authors are also grateful to the Centre for High Performance Computing (CHPC), Cape Town for access to their computational resources.

Compliance with Ethical Standards

Conflict of interest

There are no conflicts to declare.

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Authors and Affiliations

  1. 1.Department of Applied ChemistryUniversity of JohannesburgJohannesburgSouth Africa

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