Effect Of Two-dimensional SnS₂ Nanosheet Structure On The Performance Of Catalytic Hydrogen Evolution

The emerging two-dimensional（2D）nanomaterials have become candidates for platinum-based materials in the field of electrocatalytic hydrogen evolution reactions due to their unique layered structure.However,there are few reports on the intrinsic activity,conductivity,electrode stability and other aspects of the two-dimensional material and their structure.Transmission electron microscopy is a powerful means to characterize the microscopic atomic structure in the field of materials science research.Therefore,this paper uses the Transmission Electron Microscopy（TEM）to study the effect of their microstructure on the performance of electrochemical hydrogen evolution by taking pure SnS₂,SnS₂-Pt and SnS₂-Ni nanosheets as the research object,and provides a basis for the targeted improvement of electrocatalytic hydrogen evolution performance.（1）By solvothermal method,pure phase SnS₂ nanosheets were synthesized,and the SnS₂ samples were calcined at different temperatures in Ar/H₂ atmosphere to obtain three SnS₂ sample materials.In 0.5 M H₂SO₄,the overpotential of SnS₂-4 nanosheets measured at a current density of 10 m A cm^-2 is 551 m V,and the Tafel slope is 167 m V dec^-1.By comparing pure SnS₂ and annealing SnS₂ samples The electrocatalytic performance test results of the material show that SnS₂-4（350℃-8h）has the best electrocatalytic hydrogen evolution performance.（2）By doping Pt particles,a series of SnS₂-Pt composite materials with different doping concentrations were synthesized.The electrocatalytic performance shows that the overpotential of SnS₂-Pt with a Pt doping concentration of 0.5 wt%in 0.5 M H₂SO₄is 210 m V at a current density of 10 m A cm^-2,and the Tafel slope is 126 m V dec^-1.The C_dl value is 6.3 m F cm^-2.These results all indicate that SnS₂-Pt nanosheets utilize the synergistic effect between Pt and SnS₂ to promote the combination of Pt and SnS₂ active sites,increase the hydrogen production efficiency,and improve the catalytic hydrogen evolution performance.（3）By doping Ni particles,a series of SnS₂-Ni composite materials with different doping concentrations were synthesized.The SnS₂-Ni composite material was subjected to a photoelectrocatalytic hydrogen evolution test under the irradiation of 300W visible light.The photoelectrocatalytic performance showed that the overpotential of SnS₂-Ni with a Ni doping concentration of 6 wt%in 0.5 M H₂SO₄ at a current density of 10 m A cm^-2 is 408 m V,and the Tafel slope is 164 m V dec^-1.The C_dl value is 3.3 m F cm^-2.The synergistic effect between SnS₂ and Ni and the irradiation of the external light source improve the electrocatalytic HER performance of SnS₂-Ni.