Catalytic degradation of tetracycline using marigold flower-like structure erbium molybdate decorated on sulphur-doped g-C₃N₄ nanocomposite: Kinetics, thermodynamics, DFT calculations, and toxicity studies

In this study, a novel nanocomposite has been developed comprising erbium molybdate decorated on sulphur-doped graphitic carbon nitride (EMO/SGCN) acts as an effective catalyst for the degradation of tetracycline (TC) by NaBH₄. The as-prepared catalyst exhibited remarkable catalytic behavior towards the removal of TC, with degradation efficiency and rate constants (k) of 89.15% and 0.0576 min⁻¹, respectively, during the first 90 min. The TC degradation kinetics followed a pseudo-first order response based on the correlation coefficient (R²) values and adsorption capabilities. Catalytic degradation routes were spotted by GC-MS (Gas chromatography-mass spectrometry) analysis. The degradation mechanism of TC by the catalyst was suggested grounded on the experimental investigation and density functional theory calculations. Toxicity prediction was used to assess the toxicity of intermediates. Therefore, the use of EMO/SGCN in the presence of NaBH₄ for the catalytic degradation of antibiotics in wastewater treatment can provide new insights into metal composite-based catalysts.