Photocatalytic reduction of Cr(VI) by novel shuttle-like Bi2S3 nanocrystals under visible light

Heavy metal contamination in industrial wastewater poses a significant threat to the environment and public health. To address this issue, various nanocrystalline materials have emerged as promising photocatalysts for water treatment. In this research, by using ultra-high molecular weight of polyvinylpyrrolidone (PVP), a novel shuttle-like Bi₂S₃ nanocrystal was synthesized via a facile hydrothermal method. The material exhibited outstanding performance in water treatment, particularly in the photocatalytic reduction of Cr(VI) to Cr(III) under visible light. The photocatalytic performance of high concentration Cr(VI) (10 mg/L) reduction efficiency with shuttle-like Bi₂S₃ can reach near 100 % in only 5 min (k = 1.4754 min⁻¹). In-situ oxidants capture experiments confirmed ∙O²⁻ was the main active species in the reduction of Cr(VI). This study highlights a cost-effective and scalable approach to fabricating Bi₂S₃ nanocrystals, offering significant potential for morphology control of nanomaterials and industrial water treatment applications for heavy metal remediation.