Improvement of Photocatalytic Degradation and Adsorption of Ciprofloxacin by Bismuth Oxyiodide

Abstract Bismuth oxyiodide (BiOI) hierarchical structures were fabricated by the solution route at room temperature (BiOI‐R) and solvothermal synthesis (BiOI‐S) in the presence of KI and ethylene glycol to improve the photocatalytic and adsorption ability for the removal of ciprofloxacin from the aqueous environment. BiOI was characterized by X‐ray diffraction, scanning electron microscopy, N 2 adsorption‐desorption isotherm, UV‐Vis absorption spectroscopy, and pH of the point of zero charge. It was observed that BiOI‐S has better adsorption and photocatalysis capacity as a result of having higher surface area, higher light absorption ability, and lower band‐gap energy than BiOI‐R. BiOI‐S exhibited good ciprofloxacin adsorption and photocatalytic degradation under visible‐light irradiation. Adsorption isotherm and kinetic studies fitted the Langmuir and Freundlich isotherm and pseudo‐second‐order models respectively. The photocatalytic degradation of ciprofloxacin by BiOI‐S followed a pseudo‐first‐order reaction based on Langmuir‐Hinshelwood kinetics.