Gatou Maria-Anna, Bovali Natalia, Lagopati Nefeli, Pavlatou Evangelia A
Laboratory of General Chemistry, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 15772 Athens, Greece.
Laboratory of Biology, Department of Basic Medical Sciences, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
Molecules. 2024 Sep 11;29(18):4299. doi: 10.3390/molecules29184299.
The increasing global requirement for clean and safe drinking water has necessitated the development of efficient methods for the elimination of organic contaminants, especially dyes, from wastewater. This study reports the synthesis of magnesium oxide (MgO) nanoparticles via a simple precipitation approach and their thorough characterization using various techniques, including XRD, FT-IR, XPS, TGA, DLS, and FESEM. Synthesized MgO nanoparticles' photocatalytic effectiveness was evaluated towards rhodamine B and rhodamine 6G degradation under both UV and visible light irradiation. The results indicated that the MgO nanoparticles possess a face-centered cubic structure with enhanced crystallinity and purity, as well as an average crystallite size of approximately 3.20 nm. The nanoparticles demonstrated a significant BET surface area (52 m/g) and a bandgap value equal to 5.27 eV. Photocatalytic experiments indicated complete degradation of rhodamine B dye under UV light within 180 min and 83.23% degradation under visible light. For rhodamine 6G, the degradation efficiency was 92.62% under UV light and 38.71% under visible light, thus verifying the MgO catalyst's selectivity towards degradation of rhodamine B dye. Also, reusability of MgO was investigated for five experimental photocatalytic trials with very promising results, mainly against rhodamine B. Scavenging experiments confirmed that •OH radicals were the major reactive oxygen species involved in the photodegradation procedure, unraveling the molecular mechanism of the photocatalytic efficiency of MgO.
全球对清洁安全饮用水的需求不断增加，因此有必要开发高效方法以去除废水中的有机污染物，特别是染料。本研究报告了通过简单沉淀法合成氧化镁（MgO）纳米颗粒，并使用包括XRD、FT-IR、XPS、TGA、DLS和FESEM在内的各种技术对其进行全面表征。评估了合成的MgO纳米颗粒在紫外光和可见光照射下对罗丹明B和罗丹明6G降解的光催化效果。结果表明，MgO纳米颗粒具有面心立方结构，结晶度和纯度提高，平均晶粒尺寸约为3.20 nm。这些纳米颗粒具有显著的BET表面积（52 m/g）和等于5.27 eV的带隙值。光催化实验表明，罗丹明B染料在紫外光下180分钟内完全降解，在可见光下降解率为83.23%。对于罗丹明6G，在紫外光下的降解效率为92.62%，在可见光下为38.71%，从而验证了MgO催化剂对罗丹明B染料降解的选择性。此外，还对MgO进行了五次光催化实验的可重复使用性研究，结果非常有前景，主要针对罗丹明B。清除实验证实，•OH自由基是光降解过程中主要的活性氧物种，揭示了MgO光催化效率的分子机制。
