Synthesis of porous Ni@rGO nanocomposite and its synergetic effect on hydrogen sorption properties of MgH2
Synthesis of porous Ni@rGO nanocomposite and its synergetic effect on hydrogen sorption properties of MgH2
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多孔Ni@rGO纳米复合材料的合成及其对MgH2吸氢性能的协同作用
DOI：
10.1039/c2jm34730j
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发表时间：
2012-11-14
影响因子：
--
通讯作者：
Yuan, Huatang
中科院分区：
文献类型：
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作者：
Liu, Guang;Wang, Yijing;Yuan, Huatang
采用乙二醇法和热处理工艺成功地制备了多孔Ni@rGO纳米复合材料。结果表明，面心立方镍纳米颗粒固定在还原的氧化石墨烯上，形成了多孔结构。研究还发现，Ni@rGO纳米复合材料对氢氧化镁的脱氢反应具有良好的催化效果。球磨法制备的MgH2-5wt%Ni@rGO复合材料比纯MgH2具有更快的吸附动力学和更低的吸附温度。脱附峰温度由纯球磨的356℃移至247℃-5wt%Ni@rGO。在300℃下，经9次循环后，MgH2-5wt%Ni@rGO复合材料在10min内即可脱附6.0wt%H2，而未掺杂的MgH2仅在120 min内脱附2.7wt%H2。此外，活化能(Ea)明显低于氢氧化镁，在氧化镁表面存在少量还原的氧化石墨烯，阻止了纳米颗粒在循环过程中的烧结和团聚，从而提高了氢氧化镁的分解和循环稳定性。结果表明，多孔Ni@rGO复合材料对氢氧化镁的吸附性能有协同作用。
A porous Ni@rGO nanocomposite was successfully prepared by the ethylene glycol method followed by an annealing process. It was shown that fcc Ni nanoparticles anchored on reduced graphene oxide sheets producing a porous structure. It was also found that Ni@rGO nanocomposite had a good catalytic effect on de/hydrogenation of MgH2. The MgH2–5 wt% Ni@rGO composite acquired by ball milling exhibited improved faster sorption kinetics and relatively lower sorption temperature than pure MgH2. The desorption peak temperature shifted from 356 °C for pure milled MgH2 to 247 °C for MgH2–5 wt% Ni@rGO. The MgH2–5 wt% Ni@rGO composite could desorb 6.0 wt% H2 within 10 min at 300 °C even after nine cycles, in contrast, only 2.7 wt% H2 was desorbed even after 120 min for undoped MgH2. In addition, the activation energy (Ea) decreased significantly compared to MgH2 and the presence of a few layer reduced graphene oxide sheets on the MgH2 surface prevented the nanograins sintering and agglomeration during cycling, which enhanced the MgH2 decomposition and cycling stability. It was suggested that the porous Ni@rGO composite had a synergetic effect on the MgH2 sorption properties.