Insights into the complementary behaviour of Gd doping in GO/Gd/ZnO composites as an efficient candidate towards photocatalytic degradation of indigo carmine dye

Samuel Osei Bonsu Oppong, Francis Opoku, William Wilson Anku, Penny P. Govender

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

Water pollution caused by the discharge of hazardous organic pollutants from the food, textile, leather and paper industries is becoming a task for sustainable development. Photocatalysis is considered to be an effective method for removing organic contaminants from dye wastewater. The photocatalytic activity of ZnO-based catalyst based on its ability to generate electron–hole pairs upon photoillumination is limited due to its wide bandgap. In this study, novel GO/Gd/ZnO composites with varying percentages (0.3–1%) of Gd were fabricated via a hydrothermal approach and their photocatalytic degradation processes and performance of indigo carmine (IC) dye were investigated under light irradiation. The chemical composition and morphological features of the prepared GO/Gd/ZnO composites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope, energy-dispersive spectroscopy, Brunauer–Emmett–Teller, Raman and Fourier–transform infrared spectroscopy. GO/Gd/ZnO composites show much higher photocatalytic performance with complete IC dye degradation within 30 min of irradiation than bulk ZnO and GO/ZnO composite. Moreover, the optimal performance was revealed by the GO/Gd/ZnO (0.6% Gd) composite (nearly 96% degradation of IC dye). Using density functional theory, we explore the potential drop across the interface, electronic and structural properties of GO/ZnO and GO/Gd/ZnO composites. The photodegradation rate of IC dye by GO/Gd/ZnO (0.6% Gd) composite was 7.65 and 2.94-fold higher than those of bulk ZnO and GO/ZnO composite. The capture experiments revealed ˙O2 and ˙OH as the main active radicals during the photodegradation process. The theoretical and experimental findings obtained in this study indicate that GO/Gd/ZnO photocatalyst has great potential application for eliminating environmental pollutants.

Original languageEnglish
Pages (from-to)8511-8527
Number of pages17
JournalJournal of Materials Science
Volume56
Issue number14
DOIs
Publication statusPublished - May 2021

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering

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