The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, PR China; State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environment, Beijing Normal University, Beijing 100875, PR China; School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing 100083, PR China.
J Hazard Mater. 2020 Jun 5;391:121016. doi: 10.1016/j.jhazmat.2019.121016. Epub 2019 Aug 14.
In this work, a novel CdS-SnS-SnS/rGO photocatalyst with two tin valence states (Ⅱ and IV) was successfully synthesized by a one-pot solvothermal method. For comparison, CdS-SnS/rGO (GCS2) with tin in only the IV valence state was made by the same method. Based on a series of characterizations, CdS, SnS and SnS were shown to be successfully loaded onto the rGO surface. The introduction of rGO may increase charge carrier separation. The degradation efficiency increased gradually with increasing rGO loading content, and the optimum photocatalytic activity was observed at 6.0 wt% rGO loading content (GCS1), which achieved the efficient removal (84.46%) of ibuprofen over 60 min. Compared with GCS2, the CdS-SnS-SnS/rGO composite exhibited significantly improved photocatalytic performance, which can be ascribed to the formation of a double heterostructure. rGO worked as a transfer mediator to transfer electrons from the conduction band (CB) of SnS to the CB of SnS at the heterointerface, which then flowed to the CB of CdS because of another heterojunction, further enhancing the separation efficiency of photogenerated carriers. Therefore, this study highlights a novel double heterojunction system with a facial preparation method, visible light response and good recyclability, which is beneficial for environmental remediation.
在这项工作中，通过一步溶剂热法成功合成了一种具有两种锡价态（Ⅱ和Ⅳ）的新型 CdS-SnS-SnS/rGO 光催化剂。为了进行比较，通过相同的方法制备了仅具有 IV 价态锡的 CdS-SnS/rGO（GCS2）。通过一系列的表征，表明 CdS、SnS 和 SnS 成功地负载到 rGO 表面上。rGO 的引入可能会增加载流子分离。随着 rGO 负载含量的增加，降解效率逐渐提高，在 rGO 负载含量为 6.0wt%（GCS1）时观察到最佳的光催化活性，在 60 分钟内实现了布洛芬的有效去除（84.46%）。与 GCS2 相比，CdS-SnS-SnS/rGO 复合材料表现出显著提高的光催化性能，这可以归因于形成了双异质结构。rGO 作为转移介质，将 SnS 的导带（CB）中的电子转移到异质界面处的 SnS 的 CB 上，然后由于另一个异质结，电子流到 CdS 的 CB 上，进一步增强了光生载流子的分离效率。因此，这项研究突出了一种具有制备方法简单、可见光响应和良好可回收性的新型双异质结体系，有利于环境修复。
