Preparation And Electrochemical Performance Of Cobalt-based Nanocomposites

In recent years,the energy crisis and environmental problems caused by the global population have become increasingly serious.Therefore,the development of new and efficient energy storage and conversion devices has become a research hotspot.The development of these new energy devices is inseparable from the efficient and stable catalyst.Among them,cobalt?Co?has a wide range of applications in energy storage and conversion due to its rich content in the earth's crust,excellent electrical conductivity,and its series of derivatives.Therefore,we have prepared cobalt-based composite nanomaterials with different morphologies,and studied the application in different catalytic fields and devices.The specific work is as follows:?1?We develop a simple,mild and efficient method to synthesize N-doped carbon nanosheets encapsulating cobalt nanoparticles hybrid?Co@NCNSs?,which shows favorable catalytic properties toward both ORR and OER with high activity and good stability.The optimized hybrids?Co@NCNSs-900?exhibit an onset potential of 0.95 V vs.RHE and a half-wave potential of 0.85 V vs.RHE for ORR and an onset potential of 1.51 V vs.RHE,a potential of 1.59 V vs.RHE at 10 mA cm^-2 for OER,oxygen electrode activity parameter??E?of 0.802 V in alkaline electrolyte.Moreover,in Zn-air batteries comprising,Co@NCNSs-900 catalyst,it outperforms that with the commercial Pt/C catalyst in terms of the maximum power density and stability,shows great prospects in renewable energy applications.?2?We report the synthesis of iron doped cobalt diselenide nanowires on conductive carbon cloth(defined as Fe_0.1-CoSe₂/CC).Since the introduction of iron leads to more active sites,and the unique nanowire structure provides a large specific surface area,Fe_0.1-CoSe₂/CC not only has excellent glucose oxidation reaction?GOR?catalytic performance and good stability in an alkaline solution containing 0.5 M glucose,but also has good hydrogen evolution reaction?HER?catalytic performance and stability in an acidic solution.The material is assembled as a two-electrode into an alkali-acid asymmetric electrolytic cell to interrogate hydrogen,which requires only 0.72 V to achieve a current density of 10 mA cm^-2,which is expected to open up a new way for energy-saving hydrogen generation.