| Electrolyzed water is an effective method for producing hydrogen energy with low cost,no pollution and abundant production.The electrolysis water process includes two processes of electrolysis of water and hydrogen evolution and electrolysis of water and oxygen.Among them,the electrochemical oxygen evolution reaction?OER?involves 4electron?4e-?transmission,and the kinetics are slow,which is the rapid step of preparing hydrogen energy from electrolyzed water.The cobalt?Co?element in the cobalt-sulfur compound?Co-S?is close to the filling state of e02g due to the low-spin electrons of its 3d orbital electron arrangement,which is beneficial to the electron transport of the OER catalytic reaction and is often applied OER electrocatalytic reaction.However,a disadvantage of the Co-S compound as an electrocatalyst for electrolyzing water is that it is easily oxidized in an alkaline electrolyte,thereby lowering the catalytic activity of the material.When the Co-S compound is combined with an inert component or a hetero atom,the catalytic performance of Co-S can be further improved by the electron,composition,and morphology adjustment effects.Therefore,different transition metal sheet materials with different compositions were prepared by hydrothermal method and coprecipitation method.The specific research process is as follows:?1?Co9S8/ZnS/C composite material was prepared by hydrothermal method using Co?NO3?2·6H2O,Zn?NO3?2·6H2O and2,2'-thiodiacetic acid as raw materials in anhydrous ethanol solvent.On the one hand,the doping of a small amount of ZnS inert component in the Co9S8 material increases the specific surface area of the catalytic material,and its specific surface area can reach 291.677 m2·g-1.On the other hand,the synergistic effect between a small amount of the ZnS inert component and the Co9S8/C material also promotes an increase in the active site of the material.Thereby,the sheet-like composite material exhibits excellent electrocatalytic oxygen evolution performance.The results show that the sheet Co9S8/ZnS/C composite has an overpotential of 390mV at a current intensity of 10mA·cm-2 and a Tafel slope of 144mV·dec-1.The stability was measured by chronoamperometry?I-t?,the stabilization time was maintained at 12000s,indicating that the flaky Co9S8/ZnS/C catalytic material has high catalytic activity and good stability.?2?Co?NO3?2·6H2O,Zn?NO3?2·6H2O,2,2'-thiodiacetic acid,C6H12O6·H2O were used as raw materials,anhydrous ethanol and deionized water were used as solvents to prepare Co9S8/C electrocatalytic material by coprecipitation method.Co9S8/C electrocatalytic material.When the mass fraction of Zn2+is 5%,the electrolyzed water activity of Co9S8/C material is the highest.The synthesized Co9S8/C composite has an overpotential of 150mV at a current intensity of 10mA·cm-22 and a Tafel slope of 142mV·dec-1.After the stability was tested by the chronoamperometry?I-t?,the stabilization time of the 5%Co9S8/C catalyst was maintained at 12000s.The results show that the Co9S8/C catalytic material has good catalytic activity for OER,which can be contributed to the large specific surface area of the synthesized materials,leading to increasing the catalytic active sites of the materials. |
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