In the current investigation, we report a facile preparation of a series of novel g-C 3 N 4 /BiOCl x Br 1−x hybrid photocatalysts and their enhanced photoactivity under visible light irradiation. The physicochemical and optical absorption of as-prepared g-C 3 N 4 /BiOCl x Br 1−x were characterized by means of X-ray diffraction (XRD), filed-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), Fourier transform infrared spectroscopy (FT-IR) and UV–vis diffuse reflection spectroscopy (DRS). A substantial decrease in photoluminance (PL) intensity of as-prepared hybrid photocatalyst compared to g-C 3 N 4 is because of carries transfer between g-C 3 N 4 and BiOCl x Br 1−x solid solution. The florescence lifetimes of g-C 3 N 4 and the corresponding hybrid photocatalyst were measured using time correlated single photon counting (TCSPC) as well. Both DFT calculations and Mulliken electronegativity method were employed to calculate band edges in BiOCl x Br 1−x solid solutions. The high carries separation efficiency at the interface, between g-C 3 N 4 and BiOCl x Br 1−x , of the hybrid photocatalyst renders g-C 3 N 4 /BiOCl x Br 1−x highly photocatalytically active. The hybrid catalyst showed excellent stability and efficiency even after many runs of photodegradation experiments.