Fabrication Of Carbon Nanofibers With The Embedded Transition Metal Nanoparticles And Their Bifunctional Electrocatalytic

Many advanced energy conversion devices have got intensive attentions,such as metal-air batteries and water electrolytic cells are employed to cope with the energy crisis and environmental pollution.To evaluate the efficiencies of the energy conversion devices,the development of economic and efficient multi-functional electrocatalysts is vital which is helpful to promote the catalytic performances of oxygen reduction reaction and oxygen evolution reaction.Up to date,the popular electrocatalysts mainly focus on the noble-based electrocatalysts such as Pt,Ru,Ir and so on.However,the noble-based electrocatalysts still face some challenges and problems,such as the expensive cost,limited abundance and poor stability,hindering its large-scale application.Therefore,the research and development of efficient,stable and low-cost mluti-funcitonal electrocatalyst is significant and important.In this paper,the exploration of carbon-based non-noble metal composite nanocatalysts with bifunctional electrocatalytic activities were fabricated via the electrospinning technology and high temperature carbonization treatments.The main contents are summaried as follows:The metal salts and carbon nanoparticles were uniformly mixed in the precursor solution and the precursors were fabricated by electrospinning process.The fabrication and structure of N,S co-doped carbon nanofibers with the decoration of Ni Co alloy nanoparticles and embedded carbon nanoparticles composite catalyst（Ni Co/Ni Co₂S₄@CNS-800）were manipulated by the followed carbonization treatments.The embedded carbon nanoparticles are beneficial to evaluate the conductivity and stability of catalysts.The decorated Ni Co alloy nanoparticles and doped heteroatoms provided numerous active sites which are significantly promote the bi-functional catalytic performances of ORR and OER.The ORR half-wave potential and OER over potential at the current density of 10 m A cm^-2 of Ni Co/Ni Co₂S₄@CNS-800 are 0.80 V and 370 m V,which are comparable to Pt/C and Ru O₂,respectively.And the catalyst Ni Co/Ni Co₂S₄@CNS-800 exhibits the superior bi-functional catalytic activities.The fabrication and structure of N-doped mesoporous carbon nanofibers with the decoration of Fe Co alloys nanoparticles（8%-Fe Co@NCNF）were manipulated through the foaming-assisted electrospinning technology.The decorated Fe Co alloy nanoparticles and the existence of Co-N and Fe-N active sites are both significant for ORR and OER catalytic activities.The ORR half-wave potential and OER over potential at the current density of 10 m A cm^-2 of 8%-Fe Co@NCNF are 0.825 V and344 m V,which are superior to Pt/C and Ru O₂,respectively.The assembled8%-Fe Co@NCNF-based Zn-air battery presents a peak power density of 134.83 m W cm^-2 and after 216h cycles at the 5 m A cm^-2,the voltage gap of charge-discharge does not change obviously,exhibiting the outstanding bifunction catalytic performances and charge-discharge stability.