Preparation Of 3D Graphene And Carbon Nanotube Materials Based On Melamine Sponge And Their Catalytic Performance For Oxygen Reduction Reaction

With the development of society,human demand for energy is growing.On the one hand the traditional fossil fuel resources are gradually depleted,on the other hand they bring increasingly serious environmental pollution.So there is no time to delay to develop new and efficient energy,energy conversion and storage device.In recent years,fuel cells,metal air batteries and supercapacitors have attracted people's attention.However,due to the sluggish kinetic characteristics of oxygen reduction reaction(ORR),people have to develop new ORR catalysts with unique structure and enough active sites.In this paper,we prepare two kinds of novel and noble metal free carbon-based catalysts with different structures.The main research contents are as follows:1.The preparation and ORR performance of three dimension GO co-doped with metal and nitrogen(M,N-3D-GO)were studied.The 3D-GO was prepared by hydrothermal method with GO homemade by Hummers' method.The influence of type and amount of transition metal Fe,Co,Ni,hydrothermal reaction temperature and other factors on the structure and performance of the materials were studied systematically.In order to improve its ORR performance,new active sites were introduced by doping nitrogen from dicyandiamide in the pyrolysis process and the effect of pyrolysis temperature was studied.Eventually,the Fe,Ni-N-3D-GO catalyst is obtained and has good ORR performance,which is comparable to Pt/C.2.The preparation and ORR performance of carbon nanotube co-doped with iron and nitrogen(Fe,N-CNT)were studied in this part.The melamine sponge with new 3D porous structure was used as carbon source to prepare carbon nanotube.The effects of different raw material,the type and amount of iron salt,pyrolysis temperature on ORR activity was investigated in detail.The results show that appropriate amount of DICY and PVP in iron nitrate solution can promote the formation of CNT,and 900? is the best pyrolysis temperature to produce uniform CNT.Finally,we prepared a catalyst Fe,N-CNT with the onset potential of 0.966 V,half wave potential of 0.843 V,limiting current density of 5.42 mA cm-2,which is better than Pt/C.And its durability to CH3OH and stability is also better than Pt/C.