Interfacial coupling of 3D nanoflower-like Bi2O2CO3 with PANI for tetracycline photocatalytic degradation and intermediate toxicity analysis

The interface coupling between solid electronic medium and semiconductor with good electrical conductivity can promote the separation of photoinduced electron-hole pair and improve the activity of photocatalyst. Polyaniline/Bi2O2CO3 with different proportions was synthesized by simple hydrothermal method under the strong interfacial coupling between polyaniline and Bi2O2CO3. XRD, XPS and FT-IR techniques were used to confirm the successful synthesis of the composite materials. With the help of SEM and TEM techniques, the morphology and structure of the materials were understood, and the photocatalytic properties of the composite materials were determined by UV–Vis, PL and other techniques. The photocatalytic activity of the synthesized photocatalyst was evaluated by degradation of tetracycline, and the effects of sample dose, pH, anion and other factors on the photocatalytic process were explored. The intermediates during the reaction were determined by liquid chromatography mass spectrometry (LC-MS), and five degradation pathways were deduced. Toxicity Estimation Software Tool and Ecosar software were used to test the toxicity of intermediate products, which further illustrated the green safety of photocatalytic technology. We also propose a possible photocatalytic reaction mechanism based on the band structure of the material and the reactive radicals generated during the reaction.