Construction of magnetically separable NiAl LDH/Fe₃O₄–RGO nanocomposites with enhanced photocatalytic performance under visible light

Abstract

Magnetic NiAl layered doubled hydroxide (LDH)/Fe₃O₄-RGO composites were successfully synthesized via a simple hydrothermal route. The as-prepared samples were well characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The results showed that NiAl LDH nanoplatelets and Fe₃O₄ nanoparticles sized around 15 nm were uniformly anchored on the surface of graphene sheets. The NiAl LDH/Fe₃O₄-RGO₂₅ photocatalyst was employed to degrade ciprofloxacin (CIP) in an aqueous solution under visible light irradiation. It exhibited enhanced photocatalytic activity compared to pure NiAl LDH, the degradation rate of the as-prepared NiAl LDH/Fe₃O₄-RGO₂₅ was 1.5 and even 3 times faster than that of NiAl LDH/RGO₂₅ and pure NiAl LDH, respectively. This enhancement of photocatalytic activity is attributed to the addition of graphene and Fe₃O₄ NPs, which both efficiently promote the separation of charge carriers and improve the optical absorption properties, synergistically facilitating the photocatalysis process. Furthermore, the NiAl LDH/Fe₃O₄-RGO₂₅ photocatalyst was magnetically separable and exhibited stable catalytic activity, which is beneficial to its practical application.