Hydrolysis of urea induces the formation of bismuth-rich Bi4O5I2 nanosheets with promoted visible-light photoreduction of Cr (VI)

Bismuth-rich Bi4O5I2 nanosheets were prepared through progressive hydrolysis of urea in a facile solvothermal route, which is different from the conventional strategies of pH adjusting or calcination. To promote the hydrolysis of urea for the formation of Bi4O5I2 nanosheets, the type of solvents and urea concentration were the distinctive roles. Especially, urea concentration over 1.0 g but less than 3.0 g in the solvent of ethylene glycol could boost the formation of Bi4O5I2 nanosheets. Furthermore, the resulted Bi4O5I2 nanosheets possessing more negative conductive band level of -1.02 eV showed superior visible-light photoreduction activity of Cr (VI) due to the efficient separation of charge carriers. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Bismuth-rich Bi4O5I2 nanosheets were successfully prepared through progressive hydrolysis of urea in ethylene glycol solvent, and the urea concentration played a key role in promoting the formation of nanosheets. The resulting Bi4O5I2 nanosheets exhibited a more negative conductive band level, showing superior visible-light photocatalytic activity.