Application Of Phosphated MOF Composite Derivaties And Porous Carbon Materials In Electrocatalyic Reaction

An increasing demand for energy and the ensuing problems of environmental pollution are prompting scientists to develop sustainable and environment-friendly alternative energy sources for replacing the constantly consumed non-renewable resources?fossil fuels?.Hydrogen,as a renewable and clean energy source,has been proposed as the most promising candidate for future fuel due to its high mass energy density and environmental friendliness.For this reason,electrochemical water splitting is considered as a clean and effective method of producing hydrogen.The popularization and sustainable production of hydrogen require efficient and low-cost electrocatalysts for the hydrogen evolution reaction?HER?.In this paper,we summarize two cheap,readily available catalysts with high catalytic performance,and discuss the theoretical understanding and mechanism analysis of HER.The first is a self-supporting nickel phosphide-based catalyst.The Ni-MOF material loaded on NF is synthesized by a simple hydrothermal method with different treatments of nickel foam?NF?as a self-supporting substrate,nickel nitrate hexahydrate as nickel source,adding 1.4-terephthalic acid?BDC?and N,N-dimethylformamide?DMF?solvents and then further subjected to high-temperature carbonization and low-temperature phosphating to finally obtain Ni₂P/C nanocomposites.The different NF treatment methods lead to different structures of the nanocomposite materials,resulting in distinction of hydrogen evolution performance.The Ni₂P without NF shows no directional stacking of layers.After NF etched by acid and alcohol,Ni₂P exhibits needle-like growth.After NF passivated by etching and high-temperature firing,Ni₂P grows in sheet orientation.The obtained self-supporting NPC-sheet@NF composite provides a current density of 10 mA cm² at an overpotential?g?of only 97 mV,which is much lower than that of non-oriented NPC catalysts and powder catalysts in alkaline electrolytes.At the same time,the initial overpotential of the prepared NPC-sheet@NF is only 29 mV.NPC-sheet@NF composite material has outstanding electrocatalytic activity and excellent stability to HER.The second is in situ loaded Pt/Ni porous carbon material based on the hollow ZSM-5 template.Firstly,the microporous ZSM-5 molecular sieve is synthesized by one-step hydrothermal method,and then etched in the NaOH solution with different concentrations to obtain the micropore-mesoporous multi-level channel ZSM-5molecular sieve.The obtained ZSM-5 molecular sieve is subjected to Ca²⁺exchange modification,loaded with Pt/Ni metal,and carbon deposition using CH₄ as a carbon source to get a carbon material with ZSM-5 as a skeleton.Finally,remove the ZSM-5template using concentrated NaOH to obtain the in-situ loaded Pt/Ni porous carbon material?Pt/Ni@ZSM-5/C?based on the hollow ZSM-5 template.The Pt/Ni@ZSM-5/C provides a current density of 100 mA cm² at an overpotential?g?of only 245 mV.Compared with the reported hydrogen evolution performance of similar carbon materials,Pt/Ni@ZSM-5/C has shown great superiority,but we believe that the hydrogen evolution performance of this material needs to be improved.For example,doping nitrogen atoms to improve the electron arrangement of the defect sites on the surface of the hollow carbon,as well as appropriate phosphorous sulfide to greatly improve the catalytic performance of Pt/Ni@ZSM-5/C.