Research And Application Of The G-C₃N₄-Based Composites As Oxygen Electrode Catalyst

In this work,we selected g-C₃N₄ which is a new carbon material as the object of study.The g-C₃N₄ composite was fabricated by solid phase method and the raw material using melamine.In order to construct an active catalytic performance of g-C₃N₄-based composite catalyst,then modifed,the nanoseets of g-C₃N₄ were prepared by acid stripping method which increase the specific surface area of material;and loading the g-C₃N₄ with Spinel type oxide which could increase more oxygen vacancy to form heterogeneous structure and synergistically improve catalytic activity.Different proportions of g-C₃N₄/CoFe₂O₄ composite material catalysts were prepared by two-step hydrothermal method,and then the prepared sample materials were characterized and morphologically analyzed by XRD,SEM and other technologies.It can be known that the composite material catalyst of CoFe₂O₄ nanoparticles evenly distributed in g-C₃N₄ nanosheets.The catalysts were prepared by two-step hydrothermal method.Oxygen reduction reaction?ORR? and oxygen oxidation reaction?OER? were tested by the method of rotating disk electrode technology.The results indicate that the 10% g-C₃N₄/CoFe₂O₄ of percentage composite exhibits higher electrochemical performance than g-C₃N₄,pure CoFe₂O₄ or XC-72 carbon catalysts.Finally,the prepared catalysts was used to assemble the battery,and the battery performance was tested under the condition of positive oxygen The g-C₃N₄/CoFe₂O₄ composite also exhibits better performance in a Li-O₂ battery than pure CoFe₂O₄ catalysts,which includes superior discharge capacity,low charge overpotential and high cycle stability.Different proportions of g-C₃N₄/NiCo₂O₄ composite materials were prepared through two-step hydrothermal method,and employed as anode materials catalysts for non-aqueous lithium-O₂ batteries.As a result,the 10% g-C₃N₄/NiCo₂O₄ composite exhibits higher catalytic activity for an oxygen cathode than the individual component of 20% g-C₃N₄/NiCo₂O₄ and pure NiCo₂O₄ both in the ORR and OER.Otherwise,the g-C₃N₄/NiCo₂O₄ composite also exhibits better performance in a Li-O₂ battery than pure NiCo₂O₄ catalysts,which includes superior discharge capacity,low charge overpotential and high cycle stability.The above results show that building the g-C₃N₄ composite as a positive electrode catalyst for Li-air battery,which not only improves its catalytic activity in the Li-O₂ battery oxygen electrode,but also improves the stability or circularity of the Li-O₂ battery oxygen electrode.