Study On Morphology And Hydrogen Evolution Reaction Performance Of Molybdenum Carbide Catalyst

With the development of the economy,energy shortage and pollution of environment are becoming more and more serious.Hydrogen energy has been widely investigated as a clean energy source.Owing to the simple process and environmentally friendly electrolysis of water hydrogen production has become a research emphasis.Molybdenum carbides have been extensively studied as effective electrocatalysts for the HER due to the Pt-like behavior in catalytic hydrogenolysis.It is reported that the catalytic activity of molybdenum carbide is related to its micromorphology and binding energy of surface Mo.In this work,we controlled the microstructure of molybdenum carbide and treated the oxygen-containing groups on the catalyst surface.And then investigated the effect of these conditions on the catalytic performance of electrolytic hydrogen production of molybdenum carbide.The main research contents are as follows:Firstly,ultrathin molybdenum carbide nanosheet catalyst with a thickness of 4?5nm was prepared by controlling the synthesis temperature.Compared with the granular molybdenum carbide sample,the ultra-thin nanosheet had excellent electrocatalytic activity and stability.When the current density was 10 mA/cm² the overpotential was-160 mV in the 1M KOH solution,showing good electrocatalytic activity.Secondly,the oxygen-containing groups on the surface of molybdenum carbide were treated by hydrothermal procedure.The results show that in this system,some of the oxygen-containing groups on the surface of the catalyst were treated after hydrothermal treatment.The binding energy of the elements on the surface of the catalyst was changed and the electrocatalytic hydrogen evolution activity was significantly improved.Finally,element-doped molybdenum carbide catalysts were prepared.The results showed that the doping of different elements had a great influence on the microscopic morphology of molybdenum carbide.The nanorod structure S@Mo₂C/MoO₂ catalyst exhibited the best HER activity with an overpotential of-230 mV at a current density of10 mA/cm² in 0.5M H₂SO₄ solution.