Preparation Of RuCo Composite And Its Electrochemical Hydrogen Evolution Activity

Fossil energy has the problem of polluting the environment and depleting its reserves.Efficient,clean,and renewable hydrogen energy has gradually become a research hotspot that the world pays attention to.In this paper,RuCo composites were prepared by magnetron sputtering,hydrothermal and electrodeposition methods.The preparation method,morphological structure,electronic structure and electrochemical hydrogen evolution performance of RuCo composites are mainly investigated.At the same time,we analyzed the reasons for the increase in catalyst activity.The RuCo composite catalyst has excellent hydrogen evolution performance.The main research contents are as follows:(1)RuCo _MS/Ti electrodes doped with different molar content of Co were prepared by high-vacuum magnetron sputtering method.XRD analysis showed that RuCo electrodes with different molar ratios all formed an alloy structure.The morphology,element distribution and lattice fringes of Ru_1.7Co _MS/Ti were characterized and analyzed by scanning electron microscopy(SEM)and transmission electron microscopy(TEM).Among them,the grain size of Ru_1.7Co _MS/Ti is 4.9 nm,the element distribution is uniform,and the lattice spacing of RuCo alloy is 1.98(?).Electrochemical analysis shows that the addition of Co enhances the hydrogen evolution activity of RuCo.When the overpotential is 200 m V,the apparent hydrogen evolution activity current density of Ru_1.7Co _MS/Ti electrode is 87.6 m A cm^-2,which is1.39 times that of Ru _MS/Ti(63.1 m A cm^-2).At the same time,the Ru_1.7Co _MS/Ti electrode has a higher mass specific activity of 2.5 A mg^-1which is higher than the 1.8A mg^-1of the Ru _MS/Ti electrode.And the hydrogen evolution performance of Ru_1.7Co _MS/Ti electrode is higher than 40wt%Pt/C and 50wt%Ru/C with the same loading.In the electrochemical hydrogen evolution stability test,the Ru_1.7Co _MS/Ti electrode showed better hydrogen evolution stability than the RuCo _MS/Ti electrode.XPS analysis exhibited that Co modulates the electronic structure of Ru,reduces the binding energy of Ru-H,facilitates the desorption of hydrogen gas,and improves the hydrogen evolution activity of the Ru_1.7Co _MS/Ti electrode.(2)The Ru _HT-Co/Ti electrode with Ru supported on Co/Ti matrix was prepared by hydrothermal method.The surface morphology of the Ru _HT-Co/Ti electrode was characterized by SEM,which formed a special nano-network structure on the surface of the Co/Ti matrix,which improved the lack of magnetron sputtering to control the morphology of the catalyst.TEM characterization analysis shows that the interplanar spacing of Ru in the Ru _HT-Co/Ti electrode is 2.05(?)and 2.34(?).Electrochemical analysis showed that Ru _HT-Co/Ti electrode has high apparent hydrogen evolution activity and high-quality specific activity.When the overpotential is 200 m V,the current density of Ru _HT-Co/Ti reaches 81.82 m A cm^-2,and the mass specific activity is3.42 A mg^-1.The hydrogen evolution activity is better than the same loading of Ru _HT-Co,40wt%Pt/C and 50wt%Ru/C.At the same time,the mass specific activity of the Ru _HT-Co/Ti electrode is also significantly better than that of the Ru_1.7Co _MS/Ti electrode.This indicates that the special morphology brings excellent hydrogen evolution activity to the catalyst and improves the utilization rate of Ru.At the same time,it also shows the regulation effect of the Co/Ti matrix on the electronic structure of Ru,which makes it have excellent hydrogen evolution activity.On this basis,the effects of Co loading in the Co/Ti matrix,hydrothermal reaction time and hydrothermal reaction temperature on the hydrogen evolution activity of Ru _HT-Co/Ti electrodes were further explored,and the preparation process was optimized.(3)The Ru _ED-Co/Ti electrode with Ru supported on Co/Ti matrix was prepared by electrodeposition method.SEM and TEM characterization revealed that the surface of Ru _ED-Co/Ti is composed of nanoparticles with a trumpet flower-like morphology,and the average particle size of the nanoparticles is 3.08 nm.Electrochemical characterization analysis showed that Ru _ED-Co/Ti electrode has excellent hydrogen evolution activity.When the current density is 10 m A cm^-2,the overpotential is 57 m V;when the overpotential is 200 m V,the current density reaches 120.3 m A cm^-2,which is significantly better than the RuCo _MS/Ti electrode and Ru _HT-Co/Ti electrode.The Tafel slope(53.34 m V dec^-1)of Ru _ED-Co/Ti is slightly lower than 40wt%Pt/C(53.4m V dec^-1),which further proves its excellent electrochemical hydrogen evolution activity.In addition,compared with the Ru _HT-Co/Ti electrode in the previous chapter,the hydrogen evolution stability of Ru _ED-Co/Ti has been significantly improved.On this basis,the influence of deposition potential and deposition time on the hydrogen evolution activity of Ru _ED-Co/Ti electrode was also explored.Electrochemical tests found that as the potential and time increase,the apparent hydrogen evolution activity of Ru _ED-Co/Ti electrode gradually increased.Among them,the Ru _ED-Co/Ti(-0.5V-200s)electrode has the best mass specific activity,which improves the precious metal utilization rate per unit mass of Ru.