Recently, the liquid-phase ambient laser preparation and processing laboratory of the Institute of Solid State Physics, Chinese Academy of Sciences, Hefei Research Institute of Materials Science has made new progress in the preparation of pure nickel/graphene composites and the electrocatalytic oxidation of methanol.
Nano-nickel-based catalysts have been widely recognized by researchers due to their high catalytic activity and low cost, and have become important non-platinum-based catalysts. Increasing nickel utilization by decreasing the size of nickel-based catalysts is increasing nickel-based catalysts. The usual method of efficiency. However, the reduction of the nanoparticle size is always inevitably accompanied by particle agglomeration and secondary growth. Obtaining an ultrafine nickel elemental nanocrystal with a large number of exposed active sites and not agglomerated growth is to increase the nickel base. The effective way of catalyst efficiency.
In this study, a liquid-phase laser ablation method was used as a technique to obtain high-activity NiOx-loaded nanocomposites using the electrostatic interaction of Ni colloidal nanoparticles (positively charged) and graphene oxide (GO, negatively charged). The hydrazine hydrate solution is reduced to form elemental nickel. NiOx is reduced by hydrazine hydrate to generate N2 continuously, creating an oxygen-free environment for the resulting elemental nickel, and finally obtaining a highly dispersed, ultra-small size of pure elemental nickel (2.3±0.4 nm) loaded Graphene nanocomposites. Among them, the ultra-small size of nickel provides a large number of active sites for its catalytic performance. The presence of graphene greatly limits its re-growth and aggregation during the catalytic process. Experiments have shown that The material exhibits ultra-high mass specific activity (1600mA/mg) and excellent stability in the electrocatalytic oxidation of methanol. After 1000 cycles, the elemental nickel still maintains its original size and morphology, and no aggregation occurs. Second growth.
In this study, liquid-phase laser ablation technology was used to obtain the advantages of ultra-small nanocrystals. A pure nickel-loaded graphene composite material was prepared and exhibited excellent oxidation electrocatalytic performance of methanol. It was designed to synthesize other high electrochemical activity. And the stability of non-platinum catalyst nanocrystals provides new ideas and strategies.
The relevant research results were published on Chemical Communications. The research was supported by the National Key Basic Research Development Program, the National Natural Science Foundation of China, the Scientific Research Equipment Development Project of the Chinese Academy of Sciences, and the Natural Science Foundation of Anhui Province.
Figure 1. (a), Synthesis of Ni/rGO; (b), (c) Low- and high-resolution transmission images of Ni/rGO.
Figure 2. (a), Ni/rGO in 1M KOH and 1M CH, respectively 3Cyclic voltammogram in OH+KOH solution; (b) Ni/rGO in 1-6M CH 3Cyclic voltammograms in OH+KOH solution; (c) Mass activity comparisons of Ni/rGO and commercial Pt/C catalysts at different cycle times.
