Multifunctional conducting cellulose acetate–graphene oxide–La nanomembrane for waste water treatment and energy production

Abstract

The treatment of dye wastewater is crucial due to the potential toxicity of dyes and their detectability even at very low concentrations. Membrane technology offers a promising avenue for dye removal, but challenges such as membrane fouling and trade-off effects limit its efficiency. To address this, we synthesized and characterized a novel conductive membrane composed of cellulose acetate (CA)–graphene oxide (GO)–lanthanum (La) for effective dye wastewater treatment. The membrane was characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Thermogravimetric analysis, Brunauer–Emmett–Teller surface area analysis and energy-dispersive X-ray spectroscopy. Subsequently, it was employed in a dead-end filtration cell setup as the cathode in an electrochemical treatment system. Additionally, the membrane displayed antibacterial properties and showed resistance to fouling by dye molecules, enhancing its suitability for long-term wastewater treatment applications. The nanocomposite (NC), with a crystallite size of 25.0 nm, demonstrated remarkable thermal stability, retaining 28.35% char residue at 800 °C. In wastewater treatment applications, the membrane achieved a methylene blue dye rejection rate of 95.23 ± 1.05% under 35 V, with a flux of 35.45 Lm⁻² h⁻¹ bar⁻¹. Antibacterial tests showed significant inhibition of S. aureus, enhancing the microbiological safety of treated water. Photocatalytic experiments revealed a hydrogen evolution rate of 2825.67 Lmol⁻¹ g⁻¹ h⁻¹ and a total yield of 6100 ± 50 L mol⁻¹ g⁻¹. This study not only presents a novel approach for dye wastewater treatment using a membrane but also contributes to the understanding of membrane-solute interactions through comprehensive characterization techniques. The synergy of CA, GO and La in the membrane matrix provides a multifunctional platform for efficient and sustainable wastewater treatment. These results underscore the CA–GO–La membrane's potential for sustainable environmental remediation and energy production, positioning it as a versatile solution to contemporary challenges.