Synthesis Of Molybdenum Disulfide-based Nanocatalysts For Electrocatalytic Oxidation Of Ethanol

MoS₂ is one of the excellent representatives of the two-dimensional?2D?layered nanomaterial family.Because of its single-layer structure,large specific surface area and easy functionalization,it has been successfully applied to sensors,energy storage,catalysts and other fields.In order to expand the application scope of MoS₂ and improve the application performance of MoS₂,graphene,noble metal nanomaterials,metal oxides and other organic and inorganic materials are hybridized with MoS₂ to construct a series of MoS₂-based nanocomposites.On the basis of this concept,this thesis selects platinum-based nanomaterials with excellent catalytic performance as the research object to prepare a series of platinum-based nanomaterials functionalized molybdenum disulfide nanocomposites by using chemical synthesis method.Based on the preparation,this nanocomposite was used as a catalyst to explore its application in electrocatalytic oxidation toward ethanol.This thesis is mainly divided into the following two aspects:1.Shaped-controlled platinum nanoparticles-decorated molybdenum disulfide nanocomposites were prepared.We use different halogen ions?Cl^-,Br^-and I^-?to control the morphology of platinum nanoparticles.After optimized the experimental conditions,Pt nanochains?MoS₂-Pt NCHs?,Pt nanoflowers?MoS₂-Pt NFs?and Pt nanocubes?MoS₂-Pt NCs?were successfully decorated on the surface of MoS₂ nanosheet to form MoS₂-based nanocomposites due to the adjustment of Cl^-,Br^-,and I^-ions,respectively.The electrochemical results show that three kinds of molybdenum disulfide-based nanocomposites can efficiently improve the electrocatalytic ability toward ethanol oxidation.Among them,the electrochemically active surface area?ECSA?of MoS₂-Pt NCs nanocatalyst is30487.5 m²g _Pt^-1,which is 3.1 times and 73.5 times than that of MoS₂-Pt NFs(9974.6 m²g _Pt^-1)and MoS₂-Pt NCHs(415.0 m²g _Pt^-1),respectively.In addition,the MoS₂-Pt NCs nanocatalyst still has good catalytic activity after 3000 s,suggesting has better catalytic durability and stability.Experimental results showed that platinum nanoparticle functionalized molybdenum disulfide nanocomposites have broad application prospects in the field of electrocatalysis and fuel cells.2.Platinum-palladium bimetallic nanoparticles functionalized molybdenum disulfide nanocomposites?represented by MoS₂-Pd_mPt_n?were synthesized.Shape-controlled platinum-palladium bimetallic nanoparticles-supported molybdenum disulfide nanocomposites were synthesized by adjusting the platinum-palladium molar ratio with the microwave-assisted method.After exploring the effects of reaction temperature,different halogens,reaction time and surfactant on the morphology,the optimal conditions were obtained,such as the reaction temperature?130?C?,the surfactact?PVP?and morphology guider?KI?.If the molar ratio of palladium and platinum was10:1,1:1,1:10,the spherical(MoS₂-Pd₁₀Pt₁),cubic?MoS₂-Pd₁Pt₁?and flower-like(MoS₂-Pd₁Pt₁₀)platinum-palladium bimetallic nanoparticles-supported molybdenum disulfide nanocomposites were obtained with the characterization of TEM,XRD and so on.Among them,the electrochemically active surface area?ECSA?of MoS₂-Pd₁Pt₁ nanocatalyst is 857.1 m²g^-1,which is 330.0 times and17.0 times than that of MoS₂-Pd₁₀Pt₁(2.6 m²g^-1)and MoS₂-Pd₁Pt₁₀(50.7 m²g^-1),respectively.In addition,the MoS₂-Pd₁Pt₁₀ nanocatalyst still has good catalytic activity after 1500 s,suggesting has better catalytic durability and stability.