Facile synthesis of N/B-double-doped Mn2O3 and WO3 nanoparticles for dye degradation under visible light
Facile synthesis of N/B-double-doped Mn2O3 and WO3 nanoparticles for dye degradation under visible light
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DOI：
10.1080/09593330.2019.1567604
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发表时间：
2020-07
影响因子：
2.8
通讯作者：
J. H. Shah;M. Fiaz;M. Athar;Jafar Ali;Mahnoor Rubab;R. Mehmood;S. U. U. Jamil-S.-U.-U.-Jamil-14652038;R. Djellabi
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文献类型：
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作者：
J. H. Shah;M. Fiaz;M. Athar;Jafar Ali;Mahnoor Rubab;R. Mehmood;S. U. U. Jamil-S.-U.-U.-Jamil-14652038;R. Djellabi
摘要：本研究采用沉淀-水热法合成了氮掺杂和氮硼双掺杂氧化锰（Mn2O3）和氧化钨（WO3）纳米颗粒，用于可见光下亚甲基蓝的降解。使用 X 射线衍射 (XRD) 分析、扫描电子显微镜、能量色散 X 射线光谱和紫外可见光谱对材料进行表征。结果表明，N和B成功地融入到Mn2O3和WO3的晶格中。 XRD表明WO3以单斜晶格形式结晶，而立方Mn2O3以立方形式结晶。发现由于 N 和 B 元素的取代，微晶尺寸减小，这揭示了它们加速晶体成核速率导致尺寸减小的作用。另一方面，单掺杂和双掺杂成功地缩小了合成的金属氧化物光催化剂的带隙，从而在可见光中具有更好的吸收。 N-WO3、N/B-WO3、N-Mn2O3 和 N/B-Mn2O3 的带隙分别为 3.02、2.50、1.73 和 1.77 eV。光催化实验表明，所有合成材料在可见光≥420 nm下均表现出光催化效率。亚甲基蓝（MB）的降解效率顺序为：N-B共掺杂金属氧化物>N掺杂金属氧化物>金属氧化物。异丙醇、EDTA-2Na 和苯醌等清除剂分子的存在抑制了 MB 的降解。最后，结果表明这些材料可以重复使用多次，而效率不会明显下降。图解摘要
ABSTRACT In the present work, nitrogen-doped and nitrogen–boron-double-doped manganese oxide (Mn2O3) and tungsten oxide (WO3) nanoparticles were synthesized using precipitation-hydrothermal method for methylene blue degradation under visible light. Materials were characterized using X-ray diffraction (XRD) analysis, Scanning electron microscopy, Energy dispersive X-ray spectroscopy and UV-vis spectroscopy. Results showed that N and B were successfully incorporated into the crystal lattices of Mn2O3 and WO3. XRD showed that WO3 was crystallized in the form of a monoclinic lattice, while cubic Mn2O3 was produced in the cubic form. The crystallite size was found to be decreased due to the substitution of N and B elements which reveals their roles to accelerate the crystal nucleation rate resulting in the decreased size. On the other hand, single and double doping has successfully narrowed the band gaps of the as-synthesised metal oxide photocatalysts resulting in better absorption in the visible light. Band gaps obtained were as follows: 3.02, 2.50, 1.73 and 1.77 eV for N–WO3 N/B–WO3, N–Mn2O3 and N/B–Mn2O3 respectively. Photocatalytic experiments showed that all as-synthesised materials exhibited a photocatalytic efficiency under visible light ≥420 nm. The degradation efficiency of methylene blue (MB) was in the following order: N–B-co-doped metal oxides > N-doped metal oxides > metal oxides. The presence of scavenger molecules such as isopropanol, EDTA-2Na and benzoquinone inhibited MB degradation. Finally, the results showed that these materials can be reused several times without a notable decrease in efficiency. GRAPHICAL ABSTRACT