Ultrafast-Versatile-Domestic-Microwave-Oven Based Graphene Oxide Reactor for the Synthesis of Highly Efficient Graphene Based Hybrid Electrocatalysts

2018-01-14T00:00:00Z (GMT) by Barun Kumar Barman Karuna Kar Nanda
When solid graphene oxide (GO) is treated with microwave, it generates a huge amount of heat followed by reduction and exfoliation. This can be used as a high temperature reactor for ultrafast and <i>in situ</i> synthesis of reduced graphene oxide (rGO) based hybrids within 60 s in an open atmosphere. rGO based hybrids such as Fe<sub>3</sub>C-G@rGO, Co-Fe<sub>3</sub>C-G@rGO, Fe-Fe<sub>3</sub>C-NG@rGO, CoO@rGO, and Pt@rGO (G represents graphene, and NG represents N-doped graphene) have been synthesized by simply mixing appropriate precursors with GO and treating with microwave. The experiments require neither any external high temperature reactors/furnaces nor any chemical reagents or solvents. Then, rGO based hybrids have been exploited for oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and methanol oxidation activity. CoO@rGO and Co-Fe<sub>3</sub>C-G@rGO show outstanding OER performances with very low overpotential (η) and a current density of 10 mA/cm<sup>2</sup> at 1.52 and 1.56 V with long-term stability. Fe-Fe<sub>3</sub>C-NG@rGO hybrid shows better oxygen reduction performances, and the onset potential is comparable with precious Pt/C catalyst. The Pt@rGO is highly stable toward methanol oxidation as compared to the Pt/C catalyst. The high catalytic activity and stability are believed to be due to the better adherence of different inorganic nanostructures onto rGO. We strongly believe that this methodology would pave the way for a new era of synthesis of rGO based various hybrids for various applications.