We report simple and cost-effective fabrication of amorphous CuxO (x=1, 2)/crystalline Cul p-p type heterojunctions based on crystallization-mediated approaches including antisolvent crystallization and crystal reconstruction. Starting from Cul acetonitrile solution, large crystals in commercial Cul can be easily converted to aggregates consisting of small particles by the crystallization processes while the spontaneous oxidation of Cul by atmospheric/dissolved oxygen can induce the formation of trace CuxO on Cul surface. As a proof of concept, the as-fabricated CuxO/Cul heterojunctions exhibit effective photo catalytic activity towards the degradation of methyl blue and other organic pollutants under visible light irradiation, although the wide band-gap semiconductor CuI is insensible to visible light. Unexpectedly, the CuxO/Cul heterojunctions exhibit restrained photocatalytic activity when ultraviolet light is applied in addition to the visible. It is suggested that the CuxO/CuI interface can enhance the spatial separation of the electron-hole pairs with the excitation of CuxO under visible light and prolong the lifetime of photogenerated charges with high redox ability. The present work represents a critically important step in advancing the crystallization technique for potential mass production of semiconductor heterojunctions in a mild manner. (C) 2017 Elsevier B.V. All rights reserved.