Electrochemical Hydrogen Evolution Of MOFs Modified Molybdenum Disulfide Nanosheet

Hydrogen,as a new clean energy,is considered as an ideal alternative to traditional fossil fuels.Among various producing hydrogen methods,electrochemical catalytic hydrogen evolution is clean,near-zero pollution,fast and convenient.For the electrochemical catalysts of hydrogen evolution,platinum and other noble metal catalysts have lower onset potential and superior electrochemical performance,but high price and rare reserves.Molybdenum disulfide as a typical two-dimensional graphene-like structure has better electrocatalytic hydrogen evolution performance and attracted enormous attentions.MOFs?Metal-organic frameworks?are novel porous materials composed of metal ions or clusters and polyfunctional organic ligands.Due to their controlled pore structure and large specific surface areas,they have been widely used in catalysis in recent years.Through the improvement of the literature synthesis process,this thesis adopted the hydrothermal synthesis method,using thiourea as the sulfur source and sodium molybdate as the molybdenum source.At high temperature,molybdenum disulfide nanosheets were produced.A series of physical property characterizations and electrochemical catalytic performance tests were carried out.The experiment showed that the molybdenum disulfide nanosheets have higher crystallinity,better morphology feature,larger specific surface area(26m² g^-1),smaller average pore size?8.1nm?and excellent electrochemical hydrogen evolution performance.In order to further improve the electrocatalytic hydrogen evolution performance of molybdenum disulfide nanosheets,they were modified by HKUST-1 MOF material?MoS₂@HKUST-1?using stirring method.A series of characterizations such as SEM,XRD and BET test were performed on MoS₂@HKUST-1 materials.Their hydrogen evolution performances were tested.The results showed that the MoS₂@HKUST-1materials had larger specific surface area(124m² g^-1),smaller average pore size?4.6nm?,a lower onset potential?-99mV?,a smaller Tafel curve slope(69mV dec^-1)and excellent electrochemical stability in acidic media.ZIF-67 MOF material was modified on the surface of molybdenum disulfide nanosheets to obtain MoS₂@ZIF-67 materials with better hydrogen evolution performance.A series of characterizations such as SEM,XRD and BET test were performed on MoS₂@ZIF-67 materials.Their hydrogen evolution performances were tested,which showed that the MoS₂@ZIF-67 materials had larger specific surface area(253m² g^-1),smaller average pore size?3.7nm?,a lower onset potential?-49mV?,smaller Tafel curve slope(57mV dec^-1),lower electrochemical impedance?49??and superior stability.