Nickel aluminum layered double hydroxides (LDHs) fabricated via sodium citrate (SC) assistant hydrothermal route were evaluated for removing p-nitrophenol from aqueous solutions. The characterization results indicate that the NiAl-LDHs nanoparticles have well-ordered layer structure with highly crystalline nature. The NiAl-LDH possessed hierarchically porous nanoarchitectures with high surface area (108.7 m(2)/g) and great pore volume (0.41 cm(3)/g). Meanwhile, interlamellar spacing of NiAl-LDH was increased to 0.73 nm, demonstrating that the citric acid ion was intercalated into NiAl-LDH in vertical alignment. The morphology of NiAl-LDH changed from a series of disordered growth hexagon nanosheets to the flower-like microspheres with modification of variable sodium citrate. The adsorption isotherms of p-nitrophenol on NiAl-LDHs obey the Langmuir equation. It is worthy to note that the NiAl-LDH modified by sodium citrate with the addition of 2.316 g exhibits excellent adsorption performance with the maximum p-nitrophenol adsorption capacity of 77.7 mg/g. (C) 2015 Elsevier B.V. All rights reserved.