Aluminum-doped zinc oxide (AZO) conductive powders have been successfully prepared by a simple chemical coprecipitation method. The obtained powders with different post-calcining atmospheres were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM/EDS), and dynamic light scattering (DLS). The resistivity-dependent photocatalytic activity was studied by degradation of methyl orange (MO) in aqueous solution. The result showed that photodegradation of methyl orange dyes obeyed the rule of a pseudo first-order kinetics reaction and the AZO photocatalytic activity was related to the resistivity under different post-calcining atmospheres. (C) 2013 Elsevier B.V. All rights reserved.