Researchers in Lab of Laser Fabrication in Liquids, Institute of Solid State Physics, Hefei Institutes of Physical Science reported their research results on preparing pure Ni nanocrystallines-reduced graphene (Ni/rGO) with excellent activity toward methanol oxidation in Chemical Communications (Chem. Commun., 2018, 54, 1563-1566).
Nickel-based catalysts are considered as the most promising candidates among non-platinum metal catalysts, and downsizing is a simple route to enhance Ni utilization efficiency.
However, such small Ni nanoparticles are always along with aggregation and secondary growth in electrochemical reaction progress.
For acquiring optimal MOR performance, it is very important to find an efficient strategy to obtain ultrafine Ni NPs with the most exposed active sites and keep a high stability against growth and aggregation.
Based on laser ablation in liquid technology, researchers developed an easy way to prepare pure nickel nanocrystallines on graphene. These nickel nanocrystallines are highly dispersed and sized of ~2.3nm. The result product was a highly efficient catalyst toward MOR in alkaline conditions. And the phase, morphology and size of nickel nanocrystallines are successfully maintained in the process of electrocatalysis.
This facile and low-cost design probably gives some inspiration for the development of non-platinum/rGO catalysts with desirable activity and stability, which should be also significant in sustainable energy and environmental applications.
This research was supported by China í░National Key Basic Research Programí▒, í░National Natural Science Foundationí▒, í░Instrument Developing Projectí▒ of the Chinese Academy of Sciences, and et al.
Figure 1. (a) Schematic illustration of Ni/rGO, (b) low-magnification TEM image of Ni/rGO, (c) HRTEM images of ultrafine Ni nanocrystals embedded in rGO, (d) CV curves of the prepared Ni/rGO catalysts in 1 M KOH with/without 1 M CH3OH at a scan rate of 50 mV s-1, (e) CV curves of Ni/rGO at different concentration of methanol (scan rate: 50 mV s-1), (f) Catalytic mass activity of Ni/rGO and commercial Pt/C catalysts at different cycles.(Image by YE Yixing)