Pearl necklace-like ZnO–ZnWO₄ heterojunctions composites have been designed and synthesized. The photocatalytic activity of the ZnO–ZnWO₄ heterojunctions depended on the calcination temperature and ZnO–ZnWO₄ molar ratio. The ZnO–ZnWO₄ composites showed higher degradation efficiency than that of ZnO or ZnWO₄ individually. The photocatalytic reaction was enhanced due to the heterojunctions construction, which improved charge separation of the photogenerated electron–hole pairs.