Synthesis And Electrocatalytic Application MOF Derived Transition Metal-based Carbon Nanomaterials

Nano-structured materials,such as porous metal oxides,metal nanoparticles,porous carbon,and composite materials,have been widely used in energy conversion and storage devices,catalysts,and so on.In electrocatalysis,although precious metals are good catalysts,they cannot be widely used because of their high cost.Therefore,researchers have developed transition metal-based materials as efficient electrocatalysts to replace precious metal materials.Metal-organic frameworks?MOFs?thermal conversion provides a promising method for the synthesis of transition metal-based functional nanomaterials that are difficult to obtain using conventional methods.This article mainly regulates the morphology of metal-organic framework structures and prepares derived transition metal-based nano-carbon materials to develop efficient electrocatalysts.The main contents are as follows:?1?A new type of N-doped carbon-coated CoP particle/carbon nanotube composite?CNT-NC-CoP?has been synthesized by in situ nucleation and growth of ZIF-67 nanoparticles onto carbon nanotubes,which subsequently is treated with carbonization and phosphorization.Hierarchical structure endows as-obtained CNT-NC-CoP with high specific surface area,abundant exposed active sites,quick ion diffusion path,and good electrical conductivity,thus exhibiting the excellent electrocatalytic capability with the current density of 10 m A cm^-2 at the low overpotential of 251 m V and remaining long-term durability.Besides,density functional theory?DFT?calculations reveal that Co OOH/graphene interfaces are more effective for facilitating intermediates adsorption and improving the corresponding catalytic activity.?2?A novel and environmentally friendly strategy has been developed for the preparation of MOF derived carbon-coated bimetallic phosphates?Fe Ni P/C?.Fe Ni P/C-900 is a 3D hollow barrel with a high specific surface area and excellent OER catalytic performance.The current density is 10m A cm^-2 under the overpotential of 229 m V,and the Tafel slope is low of74.5 m V dec^-1.Meanwhile,the mechanism of heat transformation of P-containing MOF and the change of P bonds during heat treatment have been explored.Focusing on the MOF thermal transformation process itself and exploring the interactions among components in the MOF thermal transformation process,there is still a lot of space and significance for us to explore in this field.?3?A general method uses a series of In-based MOFs to derive two-dimensional Co,N co-doped carbon nanosheets.After high-temperature pyrolysis,the porous metal-organic framework?CPM-5?impregnated with Co?NH₃?₆³⁺can convert the three-dimensional CPM-5 structure into two-dimensional functional nanosheet.Compared with the commercially available Pt/C,the obtained porous Co,N-doped carbon nanosheets(NCNS-Co_0.5In_0.5)have excellent ORR catalytic activity,and the half-wave potential is 0.82V.Meanwhile,it also has good stability and methanol tolerance,so it is suitable as a catalyst for Zinc-Air batteries(power density132.2 m W cm^-2).This method can be easily extended to other In-based MOFs,including QMOF-2,In-MIL-68,and In OF-1,where all derived materials have efficient ORR performance.Our work provides a new way to adjust the morphology and catalytic performance of MOF derivatives.