The crucial oxidant in photocatalytic degradation of antibiotics is the photogenerated reactive oxygen species (ROS) but many photocatalytic processes suffer from low ROS generation efficiency. In this work, a Zn doping strategy is used to improve the photocatalytic oxygen activation ability of bismuth oxychloride (BiOCl) nanosheets with exposed (001) facets. Introduction of Zn into BiOCl can narrow the bandgap to extend photoresponse to visible region. Meanwhile, the separation of photoinduced charge carriers can also be promoted by increasing the valence band width of BiOCl. Furthermore, the adsorption and activation of oxygen molecules on the (001) surface are greatly enhanced by introducing more oxygen vacancies. Thus, the Zn‐BiOCl nanosheets have an excellent activity for the degradation of ciprofloxacin (CIP) under visible light by activating oxygen into superoxide radicals. The optimal ratio of Zn doping is 8% and the degradation rate is 2.6 times higher than that of BiOCl. The photocatalytic oxidation of CIP follows a pseudo‐first‐order kinetics. The removal efficiency of CIP reaches 98% in 80 min. Finally, the complete pathway of the CIP photocatalytic oxidation is unraveled by high performance liquid chromatography‐mass spectrometry. This study provides an advanced solution to promote the performance of photocatalyst to degrade organic pollutants in water.

Organic pollutants and cyanobacteria exist in water widely, which make significant impacts on human health so that appropriate methods are needed for their removal. In this work, Ni doped Bismuth oxychloride (BiOCl) photocatalysts were successfully synthesized by a simple hydrothermal method. The light absorption and charge carriers separation involved in superoxide (•O2 − ) generation can be optimized with the introduction of Ni element. And photocatalytic degradation experiments showed that the 9% Ni-BiOCl enhanced photodegradation activity of organic matter (Rh B and BPA) as well as M. aeruginosa. The degradation efficiency of Ni-BiOCl on the removal of Rh B and BPA were approximately 34.99% and 57% higher than that of pristine BiOCl. Furthermore, the algae inactivation was systematically studied by three-dimensional fluorescence spectrum. Results showed that •O2 − acted an irreplaceable role among the experiment of photocatalytic algae removal, and the details were described as •O2 − and h + first destroyed the cell wall of M. aeruginosa, secondly inactivated the active fluorescent substances in the cell, and then catalyzed the oxidation of intracellular exudates such as chlorophyll and phycocyanin as inorganic substances. This study provides a multifunctional catalyst for controlling water pollution and environmental restoration.

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