Conversion of hexavalent chromium (Cr(Ⅵ)) to trivalent chromium (Cr(Ⅲ)) is an effective way to reduce its environmental risk, especially via photoreduction process. However, over a wide range of pH values, it is still a great challenge to achieve a high removal rate, and the disposal of produced Cr(Ⅲ) should be concerned. In this work, we implemented a high removal rate at 98% for Cr(Ⅵ) and total chromium (Cr(T)) over a wide pH range (4–10) through the synergistic effect of adsorption, photoreduction and immobilization on the surface of BiOBr0.25I0.75. The substitution of bromine by iodine reduced the adsorption energy of Cr(Ⅵ) on BiOBr0.25I0.75, promoting the adsorption of Cr(Ⅵ). Meanwhile, the introduced iodine upshifted the conduction band (CB), enhancing the reduction ability for Cr(Ⅵ) to Cr(Ⅲ). The negative surface of BiOBr0.25I0.75 can capture Cr(Ⅲ), achieving a high removal rate for Cr(T). The pH-independent feature for Cr(Ⅵ) and Cr(Ⅲ) removal make BiOBr0.25I0.75 a potential material for chromium-containing wastewater treatment. This work provides an effective strategy for removing chromium over a wide pH range.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |