Abstract
The cationic basic fuchsin (BF) dye was removed from wastewater using green synthesized Zinc oxide-reduced graphene oxide nanocomposite (ZnO-rGO NC) derived from Carica papaya leaf extract (CPLE). The nanocomposite was characterized using various techniques: XRD, FT-IR, TEM, EDX, and FE-SEM. Adsorption experiments were conducted to examine the effects of several experimental parameters, including contact time, solution pH, temperature, initial dye concentration, and adsorbent dose. The highest amount BF dye removal was attained at pH 7 at a temperature range of 35 to 50°C, and equilibrium time was reached in 60 minutes. The Langmuir isotherm model provided a good fit for adsorption isotherms. The determination of thermodynamic parameters, including ΔG°, ΔH°, and ΔS°, revealed that spontaneous adsorption took place as evidenced by the negative values of ΔG°. An exothermic reaction was indicated by the values of ΔH°. ZnO-rGO NC was used to remediate basic fuchsin dye (BF) dye-polluted wastewater at 50 mg/L− 1. The maximum amount of dye adsorbed was found to be approximately 84.08 mg/g, indicating that the predominant adsorption mechanism was cation exchange. Based on the results, ZnO-rGO NC was shown to be a good adsorbent.