A coral CdS nanostructure is obtained via a simple one step synthesis with the addition of citric acid. The prepared CdS sample exhibits more superior activity for oxidation and reduction capacities compared with primitive CdS under visible light. Specifically, the CdS-0.5CA sample could reduce 100% of Cr(VI) within 2 min and degrade 94.4% of methyl orange within 180 min. Characterization results show that the dramatically increased photoactivity is attributed to improved specific surface area and meritoriously optimized charge separation after addition of citric acid. Meanwhile, the decrease of conduction band is conducive to photoreduction efficiency of CdS. In addition, the photocatalysis mechanism of CdS modified by citric acid for Cr(VI) and methyl orange removal is also investigated by a series of characterizations and experiments. In summary, this work reported a simple method to meritoriously increase photoactivity and obtained efficient bifunctional CdS modified by citric acid for photooxidation and photoreduction.

珊瑚 CdS 纳米结构是通过添加柠檬酸的简单一步合成获得的。与原始 CdS 相比，制备的 CdS 样品在可见光下表现出更优异的氧化和还原能力。具体来说，CdS-0.5CA 样品可以在 2 分钟内减少 100% 的 Cr(VI)，并在 180 分钟内降解 94.4% 的甲基橙。表征结果表明，显着增加的光活性归因于添加柠檬酸后改善的比表面积和显着优化的电荷分离。同时，导带的减小有利于CdS的光还原效率。此外，还通过一系列表征和实验研究了柠檬酸改性CdS对Cr(VI)和甲基橙去除的光催化机理。