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

In this work,we selected g-C₃N₄ as the research object.g-C₃N₄ compound was synthesized by solid phase method using melamine as raw material.In order to build high catalytic performance of g-C₃N₄-based composite catalyst,first,modification the g-C₃N₄,the mesoporous structure g-C₃N₄ nanosheets are prepared to increase the specific surface area of material;and doping the g-C₃N₄ with metal silver to change the electronic structure and reduce the surface potential barrier to improve the electrochemical performance;then,the transition metal oxide is reacted with modified g-C₃N₄ complex,the formation of heterojunctions and improve the catalytic activity.The catalysts were prepared by two-step hydrothermal method.The catalysts were characterized by XRD and other techniques.The ?-MnO₂ nanorods are uniformly distributed on the surface of the porous g-C₃N₄ sheets.Oxygen reduction reaction?ORR?and oxygen oxidation reaction?OER?were used to test the electrochemical properties of porous g-C₃N₄/?-MnO₂ prepared by the method of rotating disk electrode technology.The porous g-C₃N₄/a-MnO₂ composite exhibits higher electrochemical performance than porous g-C₃N₄,pure a-MnO₂ or XC-72 carbon catalysts.The porous g-C₃N₄/?-MnO₂ composite also exhibits better performance in a Li-air battery than pure ?-MnO₂ catalysts,which includes superior discharge capacity,low charge overpotential and high cycle stability.Through in situ deposition and growth of Ag and Co₃O₄ nanoparticles on graphitic carbon nitride sheets,an Ag-g-C₃N₄/Co₃O₄ composite was synthesized and employed as the catalyst for non-aqueous lithium-air battery.As a result,the Ag-g-C₃N₄/Co₃O₄ composite exhibits higher catalytic activity for an air cathode than the individual component of Co₃O₄ for both the ORR and OER.The Ag-g-C₃N₄/Co₃O₄ composite also exhibits better performance in a Li-air battery than pure Co₃O₄ catalysts,which includes superior discharge capacity,low charge overpotential and high cycle stability.The Co₃O₄ Nanoparticles catalyze the OER and the Ag nanoparticles catalyze the ORR.