Advanced g-C₃N₄ and bimetallic FeNi-BTC integration with carbon quantum dots for removal of microplastics and antibiotics in aqueous environments

Abstract

In this study, a novel approach was undertaken by integrating the photocatalyst graphite carbon nitride (g-C3N4) with FeNi-BTC (BTC: Benzene-1,3,5-tricarboxylic acid) and carbon quantum dots (CQDs) to enhance the interaction between semiconductors. The g-C3N4/CQD/FeNi-BTC material was synthesized using an environmentally friendly method that eschews the use of harmful solvents, using a combination of hydrothermal and microwave methods. The resulting material boasts a large pore volume (1.192 cm3g–1), a high surface area (1090 m2g–1), a small particle size (40–60 nm), and the capability to absorb visible light (2.27–2.52 eV). This material demonstrates remarkable efficiency in adsorbing microplastics, including polystyrene and polyethylene terephthalate (PET), at a concentration of 1200 mg L–1, achieving nearly 100% efficiency in just 45 minutes. Additionally, the g-C3N4/CQD/FeNi-BTC material shows significant effectiveness in degrading tetracycline, with an efficiency of 98.28% after 90 minutes of exposure to visible light irradiation. The study extensively explores factors that influence the pollutant treatment process, including time, concentration, pH value, temperature and the water source. The process of adsorbing MP on g-C3N4/CQD/Fe8Ni2BTC material is mainly physical adsorption, following pseudo-second-order reaction kinetics, endothermic reaction (ΔH > 0), and the adsorption process occurs spontaneously (ΔG < 0). This comprehensive approach provides valuable insights into the potential of the g-C3N4/CQD/FeNi-BTC material for treating pollutants in a range of aquatic environments, highlighting its versatility and effectiveness in environmental remediation.