Rime-like NiO Nanowires/nanofibers hierarchical architectures have been fabricated employing a co-precipitation reaction and electrospinning method. The synthesized hierarchical structure was characterized using SEM, XRD and BET analysis methods. The effects of growth temperature and reaction time on the morphologies of the as-prepared structures were investigated by SEM characterization and a possible mechanism for the formation of NiO hierarchical structures is proposed. Based on the nitrogen adsorption and desorption measurements, the BET surface. area of the as-obtained sample is 61.0 m(2)/g and the pore sizes of ca. 5.0 nm. The catalytic efficiency of the NiO nanomaterials developed was evaluated by the photocatalytic degradation of acetaldehyde. In comparison with sphere-like and fiber-like structures, the NiO hierarchical structures show an excellent ability to rapidly acetaldehyde pollutant, which may be attributed to its unique hierarchical and porous surface structures. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.