Figure 1. Preparation of molybdenum-based hybrid metal materials with strong coupling
The new energy conversion and storage technology is the core way to solve the current fossil energy crisis and environmental pollution problems in the world today. Cheap hydrogen electrolysis catalysts and high-capacity energy storage materials become the key to large-scale promotion of such new energy technologies. For electrolysis and aquatic products hydrogen, the active hydrogen-platinum-based catalyst is preferably a noble metal, but can not promote the use of its limited resources. in contrast, non-noble molybdenum-based material with its specific physical and chemical properties exhibited excellent water decomposition activity, but presence of a conductive material and low reunite a serious problem, which results in less exposure to the active site material and poor stability. In order to address these challenging issues, recently, Peking University Institute of Technology Guoshao Jun molybdenum team proposed fund is a kind of strong coupling preparation of hybrid material of new strategies to enhance the electrical performance of the hydrogen producing catalyst, and found that a strong coupling material for sodium exhibits excellent storage capacity, rate stability and the corresponding published in Advanced materials, link: https: //onlinelibrary.wiley .com/doi/full/10.1002/adma.201706085.
The current work first prepares molybdenum-based metal chelates with multi-stage hollow structures and prepares a series of molybdenum-based compounds (including MoP, MoS) by in-situ calcination. 2, Mo 2C and MoO 2) Between the substrate and having a hollow carbon material strongly coupled hybrid interaction (FIG. 1). Multistage hollow carbon structure (HCSS) having a high surface area, excellent conductivity and structural stability, etc., to be the best Composite substrate. The ultra-small molybdenum-based active material obtained through in-situ conversion is strongly coupled with the carbon hollow substrate material to effectively improve the conductivity and stability of the material. Electrocatalytic hydrogen production test shows that MoP@HCSs are in acidic and alkaline solutions. Both have excellent hydrogen evolution reactivity and stability. Also found that MoS 2/C HCSs as cathode materials for sodium ion batteries exhibit excellent electrochemical performance. The charge/discharge cycle at 4A/g current density is 1000 cycles, its capacity is still as high as 410mAh/g. This unique carbon nanosheet grows on MoS 2The nanosheet structure can shorten the ion transmission path, and the multi-carbon hollow structure can effectively improve the electron transport performance and relieve the stress change during charge and discharge. At the same time, this strong mutual coupling can avoid the agglomeration of the MoS2 nanosheet structure and effectively improve the electrode material. The rate performance and cycle life. This work provides new strategies and guidelines for the design of the next generation of new high-performance energy materials.
