Bio-capped and green synthesis of ZnO/g-C₃N₄ nanocomposites and its improved antibiotic and photocatalytic activities: An exceptional approach towards environmental remediation

In this research study, we have synthesized the bio-capped ZnO/g-C₃N₄ nanocomposites by employing lemon juice (Citrus limon) as a stabilizer and mediator. Fruitfully, lemon juice which contains various acidic functional groups and citric acid has the capability to block the surface of g-C₃N₄ from chemical reactivity and activated the surface of g-C₃N₄ for various reactions. Consequently, the agglomeration behavior and controlled shape of g-C₃N₄ has also been achieved. Our experimental results i.e. XRD, TEM, HRTEM, PL, FS, XPS, and PEC have confirmed that the lemon juice mediated and green g-C₃N₄ (L-CN) have good performances and remarkable visible light photocatalytic activities as compared to the chemically synthesized g-C₃N₄ (CN). Furthermore, the small surface area and low charge separation of g-C₃N₄ is upgraded by coupling with ZnO nanoparticles. It is proved that the coupling of ZnO worked as a facilitator and photoelectron modulator to enhance the charge separation of g-C₃N₄. Compared to pristine lemon-mediated green g-C₃N₄ (L-CN), the most active sample 5ZnO/L-CN showed ∼ 5-fold improvement in activities for ciprofloxacin (CIP) and methylene blue (MB) degradation. More specifically, the mineralization process and degradation pathways, and the mineralization process of ciprofloxacin (CIP) and methylene blue (MB) are suggested. Finally, our present novel research work will provide new access to synthesize the eco-friendly and bio-caped green g-C₃N₄ nanomaterials and their employment for pollutants degradation and environmental purification.