An efficient and sustainable Cu2O–TiO2 heterogeneous photocatalyst for the degradation of ciprofloxacin under visible light exposure

Antibiotic effluents from pharmaceutical industries, hospitals, and livestock industries are one of the main concerns for water pollution. A reliable, cost-effective, eco-friendly catalyst along with the possibility of reuse is badly desired for antibiotic removal from the environment. In this study, TiO2 NPs, 3% Cu2O–TiO2, and 5% Cu2O–TiO2 heterogeneous photocatalysts were synthesized in a very cost-effective route without using any organic solvent or surfactant. The structural, functional, and micro-morphological properties of the nanophotocatalysts were comprehensively studied using x-ray diffraction, Fourier transform infrared, and transmission electron microscope. UV–visible diffusive reflectance spectroscopy and photocatalytic activity evaluation experiments revealed that the 5% Cu2O–TiO2 photocatalyst exhibits a narrowed bandgap (2.75 eV) and strong visible light absorption and achieved 96.6% ciprofloxacin (CIP) degradation under 110 min visible light irradiation with a 9.5-fold higher kinetic rate constant than the TiO2 photocatalyst. The formation of the p–n junction due to the strong coupling between Cu2O and TiO2, crystal defects, and the highly dispersed fusiform shape of the mixed phase nanocomposite are attributed to such remarkable photocatalytic performance. Radicals’ scavenger test affirmed that hydroxyl radicals (·OH) served the dominant role in CIP degradation. Furthermore, Cu2O–TiO2 nanomaterial exhibits only an ∼6.6% decrease in performance after seven cycles in the reusability test. Considering the possible reusability, this Cu2O–TiO2 photocatalyst proves itself an efficient and sustainable photocatalyst and might be a viable candidate for real-world pharmaceutical effluent removal from wastewater.