2D/1D Beta-Bi₂O₃/g-C₃N₄ Composite Photocatalytic Degradation Of Antibiotic Pollutant

Antibiotics were widely in disease prevention and medical treatment of human and animals.Their increasing accumulation in environment might induce the development of antibiotic-resistant pathogens and already resulted into some potential environmental threats.The elimination of antibiotics from wastewater using visible-light-driven photocatalysts has been attracted more and more attentions due to their higher sunlight utilization compared to conventional ultraviolet photocatalysts.Graphitic carbon nitride（g-C₃N₄）is a hot metal-free polymer semiconductor possesses narrow band gap（～2.7 eV）,considerable visible light response（～465nm）and excellent structural stability,which is suitable candidate for photocatalytic degradation of antibiotics.Over the past decades,multifarious strategies（i.e.heterojunction construction,elemental doping,combination with conductive materials,design various morphology of g-C₃N₄ and mesoporous g-C₃N₄）have been adopted to enhance the photocatalytic performance of g-C₃N₄.Direct thermal polymerization of the supramolecular aggregates precursor enable to prepare the g-C₃N₄ with various morphologies.The strategy of supramolecular aggregates precursor to prepare g-C₃N₄enable to improve electronic structure、enhance the specific surface area and improve surface properties of g-C₃N₄.Then,g-C₃N₄ heterojunction with other semiconductor used to further improve inhibit the electron-hole pair recombination may be generate great synergistic effect for enhanced photocatalytic activity.In the study,the strategy of supramolecular aggregates precursor to prepare g-C₃N₄ microtube.A novel 2D/1D beta-Bi₂O₃/g-C₃N₄ composite photocatalysts were prepared by the synthesize beta-Bi₂O₃ nanosheet in suit on the surface of g-C₃N₄microtube.Several characterization methods were applied to study the morphologies and phase structures and optical properties of the synthesized photocatalysts.The obtained 2D/1D beta-Bi₂O₃/g-C₃N₄ heterostructures exhibited enhanced photodegradation of ciprofloxacin（CIP）under visible light irradiation（λ>420 nm）.The optimum photocatalytic activity of 2D/1D beta-Bi₂O₃/g-C₃N₄ for the degradation of CIP was about 4.8 times higher than of g-C₃N₄ microtube.The photocatalytic degradation activity enhancement of 2D/1D beta-Bi₂O₃/g-C₃N₄ heterostructures might be attributed to the formation of a Z-scheme system,which could show strong redox ability and promote the separation and transportation efficiencies of photo-induced charge carriers.