Design,Synthesis And Electrocatalytic Performance Of MOFs-derived Transition Metal Electrocatalytic Materials

With the exhaustion of non-renewable energy and environ ental pollution beco ing ore and ore serious,people are increasingly exploring sustainable green energy,such as wind,solar,nuclear and tidal energy.At present,electratalytic water electrolysis is an attractive and pro ising energy conversion and storage technology.Electroche ical water splitting consists of two key co ponents,one of which is oxygen evolution reaction（OER）,which takes place at the anode,and the other is the hydrogen evolution reaction（HER）occurs at the cathode.Metal-organic fra eworks（MOFs）and their derivatives have been widely used as electrocatalysts based on the advantages of high specific surface area,abundant pore structures,diverse ligands,and well-defined etal centers.MOFs that can exist stably in water ainly include zeolite i idazolate fra eworks（ZIFs）,the Institute Lavoisier（MIL）and the University of Oslo（Ui O）.Nitride,phosphide,sulfide,boride,and selenide-derived hybrid aterials of MOFs readily inherit the original porous structure with active sites,which is beneficial for ore contact with the electrolyte,and the carbonization of MOFs enables organic ligand-derived the nanocarbon atrix can i prove the electronic conductivity of the resulting aterial.In this paper,Fe Ni S₂/Ni Co₂S₄ heterojunctions and Ni-MOF-derived Fe Ni-LDH aterials were prepared on conductive substrate nickel foa by hydrother al ethod.The icroscopic orphology and che ical structure of the aterials were characterized by scanning electron icroscopy（SEM）,trans ission electron icroscopy（TEM）,X-ray diffraction（XRD）and other physical characterization ethods.And the electroche ical catalytic perfor ance of the aterial was studied by electroche ical workstation（CHI 760 e）.The ain research contents are as follows:（1）Firstly,after si ple surface oxide re oval of nickel foa（1×c）,the ZIF precursor supported by nickel foa was further vulcanized in gas phase through hydrother al reaction to obtain Fe Ni S₂/Ni Co₂S₄heterojunction nanocatalysis aterial.Benefiting fro the favorable heterostructure,the current density of 10 A c^-2 can be achieved with only 196 V for OER in 1 ol L^-1 KOH solution,the oxygen evolution overpotential re ains unchanged after 1000 cyclics volta etry scans at a scan rate of 100 V s^-1;the hydrogen evolution overpotential of 58 V can give a current density of 10 A c^-2.After 2000 cyclics volta etry scans at scan rate of 100 V s^-1,the hydrogen evolution overpotential re ained basically unchanged.In addition,the Fe Ni S₂/Ni Co₂S₄ was used as the cathode and anode to test the perfor ance of total water electrolysis.It was found that the voltage required to reach the current density of 10 A c^-2 was 1.518 V.（2）A Ni-MOF-derived Fe Ni-LDH aterial was explored through a si ple,fast,and environ entally friendly ethod.Firstly,a kind of Fe Ni-MOF with bulk orphology was synthesized on nickel foa by hydrother al reaction.The Fe Ni-MOF was soaked in sodiu thiosulfate solution for several inutes,and then stripped by anion and anion reoxidation reduction reaction,its orphology changed into a thin flower,for ing Fe Ni-LDH aterial.The electrocatalytic perfor ance test shows that the current density of 10 A c^-2 can be achieved with only201 V for OER in 1 ol L^-1 KOH.The redox che ical reaction stripping ethod proposed in this work is expected to be a fast,green and si ple strategy,providing a new idea for the synthesis of MOFs-derived transition etal nano aterials.