Structural Modifications of CdS/Graphene Oxide with Ionic Dopants of Fe/Ag for Degradation of Methylene Blue

Global demand for pollution removal agents requires advanced materials to provide a good protocol to keep clean water resources. The composition of CdS was modified with ionic dopants including iron (Fe) and silver (Ag) and is incorporated into graphene oxide (GO) nanoparticles. The obtained compositions are CdS, Fe-CdS, Ag-CdS, CdS@GO, Fe-CdS@GO, and Ag-CdS@GO that have been fabricated by the co-precipitation method and examined by several techniques to estimate the morphological, optical, and structural properties using TEM, SEM, UV–Vis analysis, and XRD. The crystallite size of the CdS@Go was measured using the Williamson-Hall (W–H) method and was found to be around 28.6 nm. Furthermore, the a-axis was found to be 5.78 Å and 5.80 Å for cubic crystals and the a-axis achieved 14.28 to 14.24 Å for an orthorhombic crystal of CdS, respectively. The average roughness varied from 32.30 ± 3.3 to 66.65 ± 10.9 nm for CdS and Ag-CdS@GO. The degradation of methylene blue (MB) is increased from 75.56, 73.87, 76.01, 81.53, 89.34, and 91.68% for CdS, Fe-CdS, Ag-CdS, CdS@GO, Fe-CdS@GO, and Ag-CdS@GO after 60 min of exposure under visible light irradiation. The pseudo-first-order constant (K_app) is increased from 4.4 × 10⁻³ to 39.4 × 10⁻³ min⁻¹ for CdS and Ag-CdS@GO.