Visible-light driven efficient elimination of organic hazardous and Cr (VI) over BiOCl modified by Chinese Baijiu distillers’ grain-based biochar

[Display omitted] •Carbonaceous materials were used to modify BiOCl.•Separaton of photoinduced carriers is boosted.•Construction of abundant OVs promotes the the generation of O2-.•DGBC/BiOCl samples possess superior visible-light photocatalytic activity. In this paper, distillers’ grains biochar (DGBC) was facilely gained by processing the distillers’ grains produced in Chinese Baijiu brewing, and the DGBC was used to modify BiOCl. The prepared DGBC/BiOCl composite photocatalysts show elevated visible light-driven catalytic performance. X-ray diffraction (XRD) and scanning electron microscope (SEM) suggest the presence of DGBC affects the crystal growth and microscopic morphology of BiOCl. The low-temperature electron paramagnetic resonance (EPR) test affirms more oxygen vacancies (OVs) exist in the DGBC/BiOCl composite photocatalysts. The 0.75-DGBC/BOC photocatalyst holds the highest efficiency for removal of rhodamine B (RhB), tetracycline (TC) and Cr (VI) compared with BiOCl, commercial TiO2 (P25) and other DGBC/BiOCl composites. Given the experimental results, the enhanced visible light responsive performance originates from the rich OVs introduced by the modification of BiOCl with DGBC and the higher separation rate of photoexcited carriers.