Graphitic Carbon Nitride Supported LaMnO3 Nanocomposite for Efficient Adsorption, Bio-Sensing and Thermodynamic Property Against Pesticides
摘要
In the present work, LaMnO₃ and GCN@LaMnO₃ NCs fabricated through solution combustion synthesis (SCS) and sonication-assisted techniques to examine structural, optical, adsorption and electrochemical characteristics. XRD analysis revealed the orthorhombic structure and the calculated crystallite sizes of 19.16 nm for LaMnO₃ and 38.19 nm for GCN@LaMnO₃. Integration of GCN to LaMnO₃ decreased the bad gap energy from 1.8 to 1.7 eV and significance in surface area as 13.32 m2 g⁻1 and pore volume as 0.268 cm3 g⁻1 compared to LaMnO₃ (4.55 m2 g⁻1 and 0.025 cm3 g⁻1). It showed enhanced dispersion stability (−48.06 mV) and decreased thermal weight loss as 55% suggesting the improved structural stability. Adsorption analysis examined at pH 9.0 and catalyst dosage 10 mg, followed second-order kinetics pathway. GCN@LaMnO₃ confirmed the superior adsorption performance towards pendimethalin at 97.74% and metolachlor at 99.44%. Thermodynamic variables described the favourable adsorption characteristics and the entropy dependent properties. An improved adsorption efficiency of GCN@LaMnO₃ NCs is associated with the GCN functionalities. Moreover, DPPH radical scavenging assay suggested the concentration-driven antioxidant property, with good inhibition performance enhanced to 74.71% for LaMnO₃ and 83.65% for GCN@LaMnO₃ NCs, for improving the electron-donating property. Electrochemical detection of spermine at optimum pH 7.0 and scan rate 10 mV s⁻1, demonstrating the decreased charge-transfer resistance as 45 Ω, increased redox reversibility as Ipc/Ipa ~ 1.05 with lower detection limit 7.3 × 10⁻3 ng μL⁻1 for GCN@LaMnO₃ NCs. Therefore, the synergistic enhancement in adsorption, anti-oxidant and electrochemical sensing characteristics represented GCN@LaMnO₃ NCs as promising multifunctional for environmental remediation and electrochemical biosensing applications.