Synthesis and characterization of fly ash–graphene oxide nanocomposite ceramic membranes

Abstract The utilization of fly ash in ceramic membrane fabrication presents a sustainable solution to reduce solid waste disposal and lower production costs, positioning it as a promising material for membrane development. In this study, fly ash‐based photocatalytic nanocomposite hybrid ceramic membranes and systematically evaluates their structural, thermal, and functional properties. X‐ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier‐transform infrared spectroscopy (FTIR) were employed to characterize the crystallinity, morphology, and functional groups. SEM imaging confirmed a defect‐free surface with a porous architecture, whereas XRD identified dominant crystalline phases, including quartz, haematite, and mullite. Thermogravimetric analysis (TGA) established 750°C as the optimal sintering temperature, yielding membranes with 30.63% porosity and an average hydraulic pore radius of 0.311 μm. To enhance photocatalytic performance, graphene oxide (GO) was integrated via spin‐coating during phase inversion, achieving a significant increase in pure water flux of 0.042 to 0.145 L/(m 2 min bar) under 1–4 kg/cm 2 transmembrane pressures. This study uniquely investigates the influence of fly ash particle size on membrane properties, providing actionable insights for selecting appropriate fly ash grades for fabrication processes. Furthermore, membranes sintered at varying temperatures were compared to validate thermal stability and structural integrity. These findings underscore the potential of fly ash‐derived ceramic membranes in sustainable water treatment applications, combining cost efficiency, waste valorization, and enhanced separation performance through tailored nanocomposite design.