Design of BiOBr0.25I0.75for synergy photoreduction Cr(Ⅵ) and capture Cr(Ⅲ) over wide pH range

作者：Lixia Jia; Xin Tan; Yanfang Li; Yizhong Zhang; Shiqian Cao; Wei Zhou^*; Xiang Huang; Lequan Liu; Tao Yu^*

来源：Chinese Chemical Letters, 2022, 33(06): 3053-3060.

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 p H 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 p H range (4–10) through the synergistic effect of adsorption,photoreduction and immobilization on the surface of Bi OBr0.25I0.75.The substitution of bromine by iodine reduced the adsorption energy of Cr(Ⅵ) on Bi OBr0.25I0.75,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 Bi OBr0.25I0.75can capture Cr(Ⅲ),achieving a high removal rate for Cr(T).The p H-independent feature for Cr(Ⅵ) and Cr(Ⅲ) removal make Bi OBr0.25I0.75a potential material for chromium-containing wastewater treatment.This work provides an effective strategy for removing chromium over a wide p H range.

• 单位
  西藏大学; 天津大学