Advanced Z-scheme H-g-C3N4/Bi2S3 nanocomposites: Boosting photocatalytic degradation of antibiotics under visible light exposure

Abnormal concentrations of antibiotics found in aquatic environments have raised serious environmental concerns. For the efficient degradation of antibiotics, it is necessary to develop photocatalysts that react to visible light. In this work, calcination and hydrothermal methods were used to synthesize bare H-g-C₃N₄ and Bi₂S₃, respectively. Various analytic methods, such as XRD, XPS, FT-IR, HR-SEM, and HR-TEM, were utilized to verify the accomplished synthesis of the materials produced. The results of ultraviolet–visible diffuse reflectance spectroscopy (UV–DRS) showed that the synthesized nanocomposites exhibited a lower band gap than the bare materials and thus greater visible-light absorption. The degradation efficacy of the bare materials and hydrothermally synthesized nanocomposites over ciprofloxacin were investigated. A high degradation efficiency of 92 % was demonstrated for ciprofloxacin using the H-g-C₃N₄/Bi₂S₃ (5 %) nanocomposite. This remarkable efficiency underscores the potential of this nanocomposite in removing antibiotic pollutants from wastewater. In addition, the electron transfer dynamics amid the two materials (H-g-C₃N₄ and Bi₂S₃) within the heterojunction was elucidated. The findings provide valuable insights into the mechanisms underlying the enhanced photocatalytic activity of nanocomposites, paving the way for further optimization and development of advanced photocatalytic systems for environmental remediation.