Abstract

Successful studies have demonstrated that citric acid can significantly improve the photocatalytic reduction efficiency of Cr(VI) over semiconductor photocatalysts as a sacrificial donor. Here, we studied the Cr(VI) photoreduction performance of citric acid monohydrate (CAM) without any semiconductor photocatalysts. Water-soluble CAM displays extremely efficient photoreduction activity for Cr(VI), which is attributed to the synergism of H⁺, C₅H₇O₅COO⁻ and hv. Hence, the role of citric acid in photoreduction of Cr(VI) may be underestimated in the previous studies. This work may open a new perspective for the development of low-cost, high-efficient and green water-soluble materials applied in heavy metal ion wastewater treatment.

Graphic abstract

Here, the water-soluble citric acid monohydrate (CAM) for application in photoreduction of Cr(VI) is reported. The results suggest that Cr(VI) photoreduction over CAM attributes to the synergism of H⁺, C₅H₇O₅COO⁻ and hv. Moreover, CAM is a promising Cr (VI) photoreductant instead of a humble sacrificial donor.

中文翻译：

---

水溶性天然有机酸，可高效还原六价铬

摘要

成功的研究表明，柠檬酸可以显着提高Cr（VI）的光催化还原效率，超过半导体作为牺牲供体的光催化剂。在这里，我们研究了没有任何半导体光催化剂的柠檬酸一水合物（CAM）的Cr（VI）光还原性能。对Cr水溶性CAM显示非常有效的光还原活性（VI），这归因于H的协同作用⁺，C ₅ H ^ ₇ ö ₅ COO ^-和HV。因此，以前的研究可能低估了柠檬酸在Cr（VI）光还原中的作用。这项工作可能为开发用于重金属离子废水处理的低成本，高效和绿色水溶性材料开辟新的视野。

图形摘要

在此，报道了用于Cr（VI）的光还原的水溶性柠檬酸一水合物（CAM）。结果表明，铬（VI）光还原超过CAM属性H的协同作用⁺，C ₅ H ^ ₇ ö ₅ COO ^-和HV。此外，CAM是一种有希望的Cr（VI）光还原剂，而不是不起眼的牺牲供体。