Fabrication uniform hollow Bi2S3 nanospheres via Kirkendall effect for photocatalytic reduction of Cr(VI) in electroplating industry wastewater.

Hazardous hexavalent chromium removal from wastewater is an urgent issue in industry environmental pollution. In this work, hollow Bi2S3 nanospheres have been successfully synthesized from unique Bi2O3 porous nanospheres via Kirkendall effect through hydrothermal process. It was found that the sulfur source and the initial Bi2O3 templates played key roles in the formation of the uniform morphologies and structures through an anion exchange process. Compared with other Bi2S3 samples, the synthesized hollow Bi2S3 nanospheres exhibited much enhanced photocatalytic ability for Cr(VI) photoreduction. XPS analysis demonstrated that Cr(VI) was reduced to less harmful Cr(III) species over hollow Bi2S3 nanospheres under visible-light irradiation. More importantly, the hollow Bi2S3 nanospheres remained high efficiency and good stability in the recycling Cr(VI) photoreduction, and exhibited remarkable Cr(VI) removal ability in actual electroplating industry wastewater treatment.