Synthesis and characterisation of 2nd layered graphene oxide nanostructures and its electrospun for water purification membrane

Abstract

The advent of nanoscience has enabled the synthesis of nanostructures with atomic-level precision across various dimensionalities. Within this landscape, two-dimensional (2D) materials have emerged as a primary focus of inquiry, owing to their exceptional carrier mobility, high surface-to-volume ratios, and inherently tunable electronic properties. Research indicates that rigorous control over morphology, lateral dimensions, and structural stability allows for the precise engineering of material functionalities. Specifically, modulating layer thickness and defect stoichiometry serves as a critical lever for optimizing performance. These refinements render 2D architectures particularly efficacious for high-performance applications in optoelectronics, electrochemical sensing, and heterogeneous catalysis. The synthesis of 2D layered graphene oxide (GO) via the modified Hummers method reveals a clear dependency on thermal conditions. By maintaining a 12-hour reaction time while varying temperatures (40 °C, 60 °C, and 80 °C), significant shifts in the material's physicochemical profile were observed. Structural evolution was confirmed through a combination of FTIR and XRD, which highlighted the successful integration of oxygen functional groups and temperature-sensitive changes in crystallinity. Interestingly, the Raman spectra indicated that defect density, represented by the D/G band intensity ratios, is directly influenced by heat, suggesting that higher temperatures alter the carbon lattice integrity. This is further supported by SEM imaging, which captured a transition toward increased exfoliation and wrinkling as the temperature rose. From a functional standpoint, the antimicrobial performance against E. coli and S. aureus peaked in samples synthesized at 40 °C and 60 °C. This suggests that while higher temperatures (80 °C) may increase exfoliation, they might simultaneously degrade the specific surface chemistry or structural features responsible for pathogen inhibition. These results underscore the importance of temperature as a tuning knob for optimizing GO for use as a novel antimicrobial agent. The SEM analysis of the electrospun poly(lactide co caprolactone (PLC) nanofibres confirmed the formation of a high-quality, non-woven membrane matrix. The images revealed a network of continuous, randomly oriented fibers with a consistently uniform diameter and smooth surface texture. Importantly, the complete absence of bead formation indicated that the electrospinning parameters, specifically solution viscosity and voltage stability, were optimized. This bead-free morphology is vital, as it directly correlates with improved mechanical stability and a more predictable pore size distribution. From a functional perspective, the random fiber orientation is highly advantageous for water treatment applications. Unlike aligned structures, this chaotic network creates tortuous flow pathways, which theoretically enhance particle capture and increase the residence time of water within the membrane. Furthermore, the inherent nanoscale porosity observed across the membrane surface suggests a high potential for efficient filtration. These structural characteristics collectively position the PLC nanofiber-based membrane as a robust candidate for advanced water purification systems. This is to be explored further as future work