NiO/Ag hybrid nanostructures synthesized using amine-functionalized NiO nanoparticles: structural, defect chemistry, morphological, optical properties and photocatalytic activity towards ciprofloxacin drug

The excessive use of antibiotics has led to the contamination of water bodies over the years. Ciprofloxacin, in particular, due to its antimicrobial properties, has been widely used, resulting in significant harm to aquatic ecosystems. The study focuses on the synthesis of NiO/Ag hybrid nanostructures by functionalization of NiO with 2-(3-aminoethylamino)propyl-trimethoxy-silane and their photocatalytic activity towards Ciprofloxacin. Structural, morphological, vibrational and optical properties are investigated using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy and photoluminescence spectroscopy (PL). Energy-dispersive X-ray spectroscopy confirms the presence of silver in the NiO/Ag hybrid nanostructures synthesized using co-precipitation method. PL revealed the quenching of emission bands with silver hybridization which leads to improvement of charge separation efficiency. The effect of different parameters such as catalyst dose, drug concentration as well as pH of the system, etc., on the photocatalytic performance of the synthesized NiO and NiO/Ag hybrid nanostructures towards degradation of Ciprofloxacin drug are studied. It is observed that photocatalytic efficiency of NiO/Ag hybrid nanostructures for Ciprofloxacin is highest for drug concentrations of 40 ppm and pH of 8. The NiO/Ag hybrid nanostructures show higher degradation rate i.e., ~ 96% towards Ciprofloxacin drug after 120 min of light exposure. On the other hand, NiO show only drug degradation efficiency of ~ 80%. Therefore, NiO/Ag hybrid nanostructures have potential towards degradation of drugs using photocatalytic processes.