The electrochemical properties of one-dimensional (1-D) nanomaterials are highly sensitive to their surface microstructure and crystal defects. MgO nanobelts were obtained by magnesium nitrate decomposition using the direct arc plasma jet chemical vapor deposition technique, with a molybdenum substrate at 950 degrees C for 5 min. The structural details, defects, and electrochemical properties of MgO nanobelts were determined. From high-resolution transmission electron microscopy, the nanobelts contain numerous contacts, rough edges, vacancies, and doping defects. Nanobelts with large surface area and oxide ions in low coordination (with O-5C(2-) and O-4C(2-), for terrace and edge sites, and O-3C(2-) for corner and kink sites) were seen by various analytical studies. The electrochemical performances of the MgO nanobelts-modified electrode were investigated using standard techniques. The unique nanostructural features and crystal defects endow MgO nanobelt with excellent electrochemical performance as demonstrated in their application in the selective determination of hydroquinone (HQ) and catechol (CC); both can be oxidized at the MgO nanobelt-modified electrode. This nanomaterial allows the sensitive determination of HQ and CC without cross-interference. The MgO nanobelts/glassy-carbon electrode exhibited high sensitivity in the selective determination of HQ and CC, with detection limits of 1 x 10(-8) M. (C) 2014 Elsevier Ltd. All rights reserved.