Study On Preparation Of AgM Composite Material And Its Electrochemical Hydrogen Evolution Activity

Hydrogen energy is one of the most promising clean energy sources that can replace fossil fuels.The low-cost production of hydrogen through the electrolysis of water is essential for the development of new sustainable energy sources.Currently,the most effective hydrogen evolution reaction(Hydrogen evolution reaction,HER)catalyst is precious metal Pt-based materials.However,platinum's high price and limited reserves limit their commercial applications.Therefore,the development of efficient and durable catalysts that can replace Pt is essential for the large-scale production of hydrogen energy.According to statistics,the earth reserves of Ag are relatively high,and its good conductivity will facilitate charge transfer.However,due to the weak hydrogen adsorption energy of Ag,the hydrogen evolution performance of Ag alone is poor in acidity and alkalinity.In order to improve the utilization rate of Ag,this article combines Ag with other metals to obtain an efficient Ag M hydrogen evolution catalyst through the synergy between the metals.The research content and conclusions are as follows.(1)First,the magnetron sputtering method combines Ag with the selected non-noble metals,and explores their composition structure and electrochemical hydrogen evolution activity.The experiment found that the activity law of the combination of Ag and Fe,Co,Ni,Al and other non-noble metals follows the principle of volcanic curve with j₀-?_H*as a function,that is,when Ag is combined with the metal closer to the top of the volcanic curve When the time,their activity is more advantageous.Among them,the combination of Ag Ni is more worthy of further discussion.For example,the current density of Ag₃₀Ni₇₀at a potential of 300 mV is 44mAcm^-2,which is much higher than the hydrogen evolution activity of Ag(0.22mAcm^-2@300 mV);at the same time,it is better than the same Ni The loading of pure Ni samples has a 16%increase.(2)In order to further explore the changes in the hydrogen evolution activity of different ratios of Ag Ni,Ag Ni samples with the molar ratio of Ag ranging from 3 to 70%were prepared.The results show that when the Ag content is 5%and Ni content is 95%,the catalytic activity of the sample reaches the highest value(55mAcm^-2@300 mV),which is34%higher than pure Ni(41mAcm^-2@300 mV).The changes in hydrogen evolution activity of Ni electrodes with different loadings prove that the increase in the activity of Ag₅Ni₉₅is not due to the increase in the loading of Ni.SEM and TEM characterization prove that the particle size of Ag₅Ni₉₅is much smaller than that of Ag and is smaller than that of pure Ni,indicating that Ag₅Ni₉₅has a larger specific surface area,and the increased active sites improve the electrochemical hydrogen evolution activity;in addition,XRD and XPS indicate that Ag₅Ni₉₅is an alloy The change of electronic structure between metals effectively regulates the hydrogen evolution activity of Ag Ni.At the same time,the impedance test showed that Ag₅Ni₉₅has the smallest charge transfer resistance,which is conducive to the rapid occurrence of hydrogen evolution reaction.(3)By modifying a small amount of Ir on the surface of Ag Ni with different proportions,Ir/Ag_xNi_1-xwas obtained.Electrochemical tests show that after adding Ir,the hydrogen evolution activity of Ir/Ag_xNi_1-xis generally higher than that of Ag_xNi_1-x.CV analysis shows that the introduction of Ir promotes the hydrogen adsorption capacity of the sample,thereby increasing the hydrogen evolution activity.Among them,when Ag₅Ni₉₅is used as the substrate,Ir/Ag_xNi_1-xhas the best hydrogen evolution activity.When Ag or Ni alone is used as the substrate,the hydrogen evolution activity is reduced compared with Ir/Ag₅Ni₉₅This shows that when the content of Ag is 5%and the content of Ni is 95%,the synergy between Ag and Ni can be maximized to increase the hydrogen evolution activity.