Achieving the Enhanced Photocatalytic Degradation of Ceftriaxone Sodium Using CdS-g-C3N4 Nanocomposite under Visible Light Irradiation: RSM Modeling and Optimization

In this research, the cadmium sulfide—graphite carbon nitride (CdS-g-C3N4) nanocomposite was synthesized and characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy-dispersive spectrometer (EDX), transmission (TEM) techniques. The photocatalytic activity of as-prepared evaluated in degradation ceftriaxone sodium (CTX) antibiotic from aqueous solution under visible light irradiation. influence operational variables such as amount photocatalyst (g/L), initial CTX concentration (mg/L), pH, irradiation time (min) on photodegradation process investigated optimized using response surface methodology (RSM)—central composite design (CCD) model. maximum percentage (92.55%) obtained optimal condition, including 0.06 g/L CdS-g-C3N4 photocatalyst, 15 mg/L CTX, pH = 10.5, 81 min. efficient performance is due to appropriate alignment energy levels between CdS g-C3N4, which synergistically impact charge separation efficiency CTX. kinetics well described Langmuir–Hinshelwood’s pseudo-first-order model (kapp 0.0336 min−1).