Kisała Joanna, Wojnarowska-Nowak Renata, Bobitski Yaroslav
Institute of Biology, University of Rzeszow, Pigonia 1 Str., 35-310, Rzeszow, Poland.
Institute of Materials Science, College of Natural Sciences, University of Rzeszow, Pigonia 1 Str., 35-959, Rzeszow, Poland.
Sci Rep. 2023 Aug 29;13(1):14148. doi: 10.1038/s41598-023-41279-y.
Photocatalytic degradation is a promising method for removing persistent organic pollutants from water because of its low cost (see solar-driven photocatalysis), high mineralisation of pollutants, and low environmental impact. Photocatalysts based on transition metal dichalcogenides (TMDs) have recently attracting high scientific interest due to their unique electrical, mechanical, and optical properties. A MoS photocatalyst of the layered structure was managed to photodegrade methylene blue (MB) under visible light irradiation. The catalyst was thoroughly characterised using SEM, AFM, powder XRD, UV-Vis, Raman, and XPS measurements. The photocatalytic degradation of the MB solution was conducted under the following conditions: (i) reductive and (ii) oxidative. The impact of optical and electronic properties, and the MoS-MB interaction on photocatalytic activity, was discussed. The apparent rate constants (k) of degradation were 3.7 × 10; 7.7 × 10; 81.7 × 10 min for photolysis, oxidative photocatalysis, and reductive photocatalysis. Comparison of the degradation efficiency of MB in reductive and oxidative processes indicates the important role of the reaction with the surface electron. In the oxidation process, oxygen reacts with an electron to form a superoxide anion radical involved in further transformations of the dye, whereas, in the reduction process, the addition of an electron destabilises the chromophore ring and leads to its rupture.
光催化降解因其成本低（见太阳能驱动的光催化）、污染物矿化程度高以及对环境影响小，是一种从水中去除持久性有机污染物的有前景的方法。基于过渡金属二硫属化物（TMDs）的光催化剂由于其独特的电学、力学和光学性质，最近引起了科学界的高度关注。一种层状结构的MoS光催化剂在可见光照射下成功地对亚甲基蓝（MB）进行了光降解。使用扫描电子显微镜（SEM）、原子力显微镜（AFM）、粉末X射线衍射（XRD）、紫外可见光谱（UV-Vis）、拉曼光谱和X射线光电子能谱（XPS）测量对该催化剂进行了全面表征。MB溶液的光催化降解在以下条件下进行：（i）还原和（ii）氧化。讨论了光学和电子性质以及MoS与MB的相互作用对光催化活性的影响。光解、氧化光催化和还原光催化的降解表观速率常数（k）分别为3.7×10⁻³、7.7×10⁻³和81.7×10⁻³ min⁻¹。MB在还原和氧化过程中降解效率的比较表明了与表面电子反应的重要作用。在氧化过程中，氧与电子反应形成超氧阴离子自由基，参与染料的进一步转化，而在还原过程中，电子的加入使发色团环不稳定并导致其破裂。
