Integrating ZnO/CdS Schottky junction for remarkably enhanced photocatalytic performance under solar spectrum

Metal-oxide/sulfide-based semiconductor nanocomposites have been investigated as micro-/nanocatalysts for the photocatalytic degradation of pharmaceuticals in wastewater. The novelty of these micro-/nanocomposite materials is in their relative ease of synthesis, their ability to rein energy in the UV–visible range, their general high surface to mass ratio, wide bandgap, non-toxicity, low cost, etc. The most effective technique for maximizing solar spectrum utilization is the sensitization of a wide-bandgap semiconductor with a narrow-bandgap material. Ciprofloxacin is an inclusive chemically synthetic medication (antibiotic) of the fluoroquinolone group often traced in infirmary wastewater, surface water, and sewage remediation plant effluent. The extant inquisition examines the Ciprofloxacin (pharmaceutical drug) diminution from the water via photocatalysis process using ZnO/CdS micro-/nanocomposite, synthesized at different concentrations by an exotic massive and environmental friendly co-precipitation approach employing cadmium nitrate tetrahydrate and zinc acetate dihydrate as precursors and ethanol–water mixture in 1:1 volume ratio was used as a solvent. SEM (scanning electron microscopy), UV–visible spectroscopy, and PL (photoluminescence analysis) was applied to characterize the micro/nanoparticles. SEM images revealed micro/nanoclusters-like morphology. The optical bandgap energy (E_g) of the synthesized material was acquired from the UV–visible absorption spectra using Tauc’s equation which is tunable between 2.69 and 3.23 eV. ZnO/CdS micro-/nanocomposites had shown sharp yellow and narrow green and blue PL emission bands, increased Cd and S concentrations caused PL quenching, ascribed to increased charge separation characteristics, which improves photocatalytic performance. The reaction rate constants were calculated using photodegradation kinetics, which revealed that it follows pseudo-first-order kinetics.