Photoelectrochemical degradation of eosin yellowish dye on exfoliated graphite–ZnO nanocomposite electrode

In the quest for harnessing more power from the sun for water treatment by photoelectrochemical degradation, we prepared a novel photoanode of exfoliated graphite (EG)–ZnO nanocomposite. The nanocomposite was characterised by X-ray diffractometry, energy dispersive spectroscopy, Brunauer–Emmett–Teller surface area analyser, thermal gravimetric analyser, and X-ray photoelectron spectroscopy. The EG–ZnO nanocomposite was fabricated into a photoanode and applied for the photoelectrochemical degradation of 0.1 × 10⁻⁴ M eosin yellowish dye in 0.1 M Na₂SO₄ under visible light irradiation. The degradation was monitored with a visible spectrophotometer. The photoelectrochemical degradation process resulted in enhanced degradation efficiency of ca. 93 % with kinetic rate of 11.0 × 10⁻³ min⁻¹ over photolysis and electrochemical oxidation processes which exhibited lower degradation efficiencies of 35 and 40 % respectively.