Bi-component Cu2O-CuCl composites with tunable oxygen vacancies contents have been successfully fabricated via the introduction of Cl source using a simple hydrothermal reduction method. The morphology, composition and structure of the prepared catalysts were characterized by FE-SEM, HR-TEM, EDS, XRD, XPS, EPR, UV-vis DRS and N-2 adsorption-desorption. The O/Cl ratios of the microcube Cu2O-CuCl composites can be easily tuned by the glucose amount. The results indicate that oxygen vacancies contents and E-g values of the as-prepared samples are heavily dependent on the O/Cl ratios. Compared with the single component Cu2O sample, the Cu2O-CuCl composites show higher oxygen vacancies contents and narrower band gaps. These findings reveal that the introduction of Cl promotes the efficiencies of light harvest and charge carrier separation, ultimately enhancing the photodecoloration performance of MB. (C) 2015 Elsevier B.V. All rights reserved.