High-efficiency and rapid photocatalytic degradation of rhodamine B and tetracycline by BiOBr nanosheets under simulated solar light

Bismuth-based photocatalyst has garnered significant attention for degrading dyes and antibiotics in wastewater. However, their photocatalytic performance remains limited due to the high recombination rate of photoinduced carriers. Constructing a bismuth-based photocatalyst with high-efficiency and rapid degradation performance is crucial for its practical application. In this study, BiOBr nanosheets, with an ultra-thin structure and abundant (001) facet exposure, exhibiting stable photoelectric conversion ability, were successfully synthesized through a simply solvothermal method. Under simulated solar light irradiation, the catalyst achieved 100 % degradation of rhodamine B within 5 min and 97.6 % degradation of tetracycline within 30 min, while over 90 % degradation efficiency after 5 cycles was preserved, demonstrating high, rapid and stable performance of the catalyst. Moreover, 90.7 % and 44.5 % of removal and mineralization efficiencies for TC within 30 min were observed under natural sunlight irradiation. Superoxide radicals and photo-generated holes were the primary species responsible for the degradation of pollutants and the former contributed more effect in long reaction time. Finally, a possible photocatalytic oxidation pathway of tetracycline was proposed based on identified five main intermediates. The BiOBr nanosheets catalyst exhibits great potential for industrial applications in the elimination of hazardous and difficult-to-degrade organic pollutants in wastewater.