Indigo carmine ic

A thin film of pPy was electrodeposited onto the surface-modified Au-Si wafer (1.5 cm × 0.5 cm area) by applying a constant potential of 0.70 V (vs. Ag/AgCl) in an aqueous solution containing 200 mM pyrrole and 25 mM indigo carmine (IC, Sigma Aldrich)^{11 (link)}. The thickness of the pPy layer was determined by controlling the charge per unit area. All thickness profiles and roughness characteristics of the pPy samples were obtained using a Dektak 150 instrument. Cyclic voltammetry (CV) was performed in 0.2 M HCl solutions at various potential windows and scan rates. After electrodeposition of the pPy layer on the Au electrode, the electrode was rinsed with DI water and dried under a fixed relative humidity (30 %) and temperature (23 °C). The surface morphologies of the delaminated pPy layer and the Au surfaces after delamination were observed by field emission scanning electron microscopy (FE-SEM) (S-4800, Hitachi High-Technology).

The chemicals necessary for the synthesis of the Mo-LDH phase, e.g., magnesium nitrate hexahydrate Mg(NO₃)₂∙6H₂O, aluminum nitrate nonahydrate Al(NO₃)₃∙9H₂O, sodium molybdate dihydrate Na₂MoO₄∙2H₂O, anhydrous sodium carbonate Na₂CO₃, and sodium hydroxide NaOH (pearls), were all of chemical purity grade and were purchased from Merck (Darmstadt, Germany). For the preparation of the GO phase, graphite powder 325 mesh from Sigma–Aldrich (Saint Louis, MO, USA), sodium nitrate NaNO₃, potassium permanganate KMnO₄ (chemical purity from Merck), H₂SO₄ (98%), hydrochloric acid HCl 37% (from Merck), and hydrogen peroxide H₂O₂ 30% (from ChimReactiv, Bucharest, Romania) were utilized.
Indigo carmine (IC) from Sigma–Aldrich (Saint Louis, MO, USA) was used to prepare the simulated dye-contaminated water in the laboratory.
All the aqueous solutions were obtained using distilled water with a conductivity of 2.5–5 μS/cm.