Study On Synthesis Of Metal Phosphide And Electrochemistry Performance Of Hydrogen Evolution

Energy is an important cornerstone of economic development and social progress in all countries of the world.At present,the energy structure of all countries in the world is dominated by fossil energy,but the reserves of non-renewable fossil energy are limited.The development of clean,renewable and new energy sources is imminent.Hydrogen energy came into being.For the new generation of energy systems,such as biological hydrogen production,photolysis of water to produce hydrogen and electrolysis of water to produce hydrogen have received highly attention.Among them,electrolyzed water products hydrogen efficiently and has mature industries,and it is expected to become the most extensive method for industrial to product hydrogen.The development of hydrogen is very promising.Platinum-carbon materials have occupied a major position on anode materials,but Transition metal phosphides have received much attention for the high cost of precious metal catalysts in recent years.Therefore,our group used solvothermal method to prepare a variety of transition metal phosphides,and in-depth study of a variety of transition metal phosphides,as follows:?1?First,CoNi-metal alkoxide precursors were prepared by solvothermal method.Then,the CoNi-P_x@C catalysts were prepared by calcining the mixture of the precursors and red phosphorus at high temperature.SEM,TEM,EDS and XPS were used to characterize the morphology,structure,and composition of the catalysts.The electrocatalytic activity and stability of HER were evaluated by linear sweep voltammetry and chronoamperometry in 0.5 M H₂SO₄ solution.It is clear that the initial potential of as-prepared Co₁Ni₁-P@C catalyst?the molar ratio of Co/Ni was 1:1?was only 96 mV and the Tafel slope was only 73 mVdec^-1.In addition,the overpotential at 10 mA cm^-2 was only 169 mV and only increased by 25 mV after5000 cycles.The authors suggested that the excellent electrocatalytic activity may be attributed to the synergistic effect of CoP and Ni₂P.?2?CoCd-metal alkoxide precursors were prepared by solvothermal method.Under an inert gas,the Co_x?Cd_y?-P@C catalysts were prepared by phosphating the mixture of precursors calcined at low temperatures and sodium hypophosphite.SEM,TEM,EDS and XPS were used to characterize the morphology,structure,and composition of the catalysts.The electrocatalytic activity and stability of HER were evaluated by linear sweep voltammetry and chronoamperometry in 0.5 M H₂SO₄solution.In the high-temperature carbonization process,cadmium ions were reduced by carbon to cadmium.The samples only consisted of cobalt and carbon after cadmium are volatilized.It is clear that the initial potential of as-prepared Co₂?Cd₁?-P@C-900 catalyst?the molar ratio of Co/Cd was 2:1?was only 43 mV and the Tafel slope was only 53 mV dec^-1.In addition,the overpotential at 10 mA cm^-2was only 99 mV and only increased by 7 mV after 4000 cycles.The authors suggested that the porous structure produced by high-temperature evaporation of cadmium improves the mass transfer diffusion efficiency and exposures more catalytically active sites in the catalyst.