Department of Physics, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.
College of Skills and Entrepreneurship, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.
Phys Chem Chem Phys. 2023 Jun 28;25(25):17043-17057. doi: 10.1039/d3cp02077k.
In this study, pristine SnS and SnS/reduced graphene oxide nanostructures were synthesized using a simple and cheap co-precipitation method. To investigate the effect of graphene oxide concentration on the structural and optical properties and photocatalytic activity, SnS/graphene oxide nanocomposites were prepared with different concentrations of graphene oxide (5, 15, and 25 wt%). The synthesized nanostructures were analyzed using X-ray diffraction, FESEM, Raman spectroscopy, UV-Vis spectroscopy, photoluminescence techniques, and electrochemical impedance spectroscopy. The results of the XRD analysis confirmed the orthorhombic phase of tin sulfide for all nanostructures. The absence of a peak at 2 = 10.21° for SnS/graphene oxide nanocomposites indicated that during the synthesis process, graphene oxide turns into reduced graphene oxide. The FESEM analysis results showed that surface cracking occurs for SnS/graphene oxide nanocomposites compared to pure graphene oxide sheets. This cracking of reduced graphene oxide sheets can act as sites for the growth of SnS nuclei on rGO. However, the presence of such nucleus sites for the growth of nanoparticles is an important factor in improving the photocatalytic efficiency of nanocomposites. The results of the Raman analysis of the nanocomposites show the highest reduction of oxygen for the SnS/rGO nanocomposite with 15 wt% concentration of graphene oxide, and this improves the conductivity and increases the separation of charge carriers. These results are confirmed by electrochemical impedance analysis with the longest lifetime (430 ns) and photoluminescence analysis with the least recombination of charge carriers for this nanocomposite. Therefore, the results of the research on the photocatalytic activity of the synthesized nanostructures for the decomposition of methylene blue under visible light irradiation show that the SnS/rGO nanocomposite has a higher efficiency than pristine SnS, and the optimal concentration of graphene oxide in the nanocomposites synthesized for 150 minutes to obtain the highest photocatalytic efficiency (more than 90%) was 15 wt%.
在这项研究中，使用简单且廉价的共沉淀法合成了原始的 SnS 和 SnS/还原氧化石墨烯纳米结构。为了研究氧化石墨烯浓度对结构和光学性能以及光催化活性的影响，使用不同浓度的氧化石墨烯（5、15 和 25wt%）制备了 SnS/氧化石墨烯纳米复合材料。使用 X 射线衍射、FESEM、拉曼光谱、UV-Vis 光谱、光致发光技术和电化学阻抗谱对合成的纳米结构进行了分析。XRD 分析的结果证实了所有纳米结构均为正交相的硫化锡。SnS/氧化石墨烯纳米复合材料中不存在 2θ=10.21°的峰表明，在合成过程中，氧化石墨烯转化为还原氧化石墨烯。FESEM 分析结果表明，与纯氧化石墨烯片相比，SnS/氧化石墨烯纳米复合材料表面出现裂纹。还原氧化石墨烯片的这种裂纹可以作为 rGO 上 SnS 核生长的位点。然而，纳米颗粒生长的核位点的存在是提高纳米复合材料光催化效率的一个重要因素。纳米复合材料的拉曼分析结果表明，氧化石墨烯浓度为 15wt%的 SnS/rGO 纳米复合材料的氧还原程度最高，这提高了导电性并增加了载流子的分离。电化学阻抗分析也证实了这一点，该纳米复合材料具有最长的寿命（430ns），光致发光分析表明载流子复合最少。因此，在可见光照射下对合成的纳米结构进行的光催化活性研究表明，SnS/rGO 纳米复合材料的效率高于原始 SnS，并且在 150 分钟内合成的纳米复合材料中氧化石墨烯的最佳浓度为 15wt%，以获得最高的光催化效率（超过 90%）。
