Tailoring hydrophily and composition of BiOI for an ultrafast photodegradation of tetracycline hydrochloride

The improvements of light absorption, charge separation and conductivity are the most common methods to enhance the degradation performance of photocatalysts. But the enhancement of hydrophily of photocatalyst is equally important and the designed approach is rarely reported. Here, a simple method to introduce hydrophilic hydroxyl (-OH) on BiOI is proposed by adding citric acid into the reactive system. Further, the conductive metal Bi is grown on BiOI by in-situ reduction. Benefiting from the elevated hydrophily, specific surface area, conductivity and photoinduced carrier separation efficiency, the optimized catalyst shows the outstanding photodegradation of methyl blue and tetracycline hydrochloride (both >90% removal ratio in 15 min). This work opens up a new way to design the high-performance photocatalyst. • The Bi and -OH co-modified BiOI is synthesized by a simple hydrothermal method. • The metal Bi improves the conductivity of BiOI and acts as the electron acceptor. • The superficial -OH prompts the adsorption capacity of hydrosoluble contaminant. • The superficial -OH enhances the hydrophily and works as the hole acceptor. • The optimized catalyst shows the ultrafast MB and TCH removal.