Exploring the catalytic degradation of 4-nitrophenol and in vitro cytotoxicity of gold nanoparticle-doped NiAlTi LDH

Abstract

Nanoparticles have gained significant interest in both the diagnosis and therapeutic intervention of cancer. Here we describe a novel fabrication of gold-supported flower-like NiAlTi LDH by using a two-step process: first, a hydrothermal route for flower-like NiAlTi LDH synthesis and second, an ion-exchange and sodium borohydride reduction method for supporting gold over the NiAlTi LDH. The assembled Au@NiAlTi LDH nanomaterial was characterized by a variety of physicochemical techniques – XRD, FTIR, and TEM. The gold nanoparticles were found to be well supported over the surface of NiAlTi LDH, and were spherical and oval in shape with an average diameter ranging from 30 to 50 nm. Furthermore, we show the anticancer activity of the Au@NiAlTi LDH nanoparticles for the first time in human lung adenocarcinoma through an in vitro cytotoxicity assay. The cytotoxicity of Au@NiAlTi LDH is concentration-dependent, displaying an IC₅₀ value of 441 μg ml⁻¹. We also tested the ability of the fabricated nano-hybrid in facilitating the catalytic degradation of 4-nitrophenol for wastewater remediation. The nanocatalyst was found to be an efficient agent for the catalytic degradation of 4-nitrophenol. The values of rate constant (k) and activation energy (E_a) were estimated as – 0.425 min⁻¹ and 12.5 kJ mol⁻¹, respectively. The thermodynamic parameters (ΔH, ΔS and ΔG) indicate that the degradation of p-nitrophenol is an endothermic and spontaneous process. In addition, Au@NiAlTi LDH exhibits excellent reusability in the degradation of organic contaminants without a reportable performance falloff.