Graphene-encapsulated Fe3O4 nanoparticles with 3D laminated structure as superior anode in lithium ion batteries

Fe₃O₄–graphene composites with three‐dimensional laminated structures have been synthesised by a simple in situ hydrothermal method. From field‐emission and transmission electron microscopy results, the Fe₃O₄ nanoparticles, around 3–15 nm in size, are highly encapsulated in a graphene nanosheet matrix. The reversible Li‐cycling properties of Fe₃O₄–graphene have been evaluated by galvanostatic discharge–charge cycling, cyclic voltammetry and impedance spectroscopy. Results show that the Fe₃O₄–graphene nanocomposite with a graphene content of 38.0 wt % exhibits a stable capacity of about 650 mAh g^?1 with no noticeable fading for up to 100 cycles in the voltage range of 0.0–3.0 V. The superior performance of Fe₃O₄–graphene is clearly established by comparison of the results with those from bare Fe₃O₄. The graphene nanosheets in the composite materials could act not only as lithium storage active materials, but also as an electronically conductive matrix to improve the electrochemical performance of Fe₃O₄.     

Mn掺杂的铁电半导体BiFeO3本征光催化氧化水活性的研究

开发稳定高效的可见光吸收的氧化物半导体光催化剂是太阳能光催化分解水的一个重要研究方向.最近我们提出(J.Mater.Chem.A,2020,8,6863?6873),具有室温铁电性质的BiFeO3(BFO)薄膜体系表现出低光电流密度响应是由于铁电畴壁/界面处的电荷复合,而该作用在纳米粒子催化剂体系中应该会大大减少.为了...