Preparation Of Molybdenum Compounds/Carbon Nanocomposites And Their Study In Electroanalytic Application

Carbon nanotubes and graphene are very important parts of carbon nanomaterials.As widely used catalytic carrier materials currently,they possess many unique properties,such as larger surface area,good mechanical strength and electrical conductivity.Transition metal compounds,such as transition metal nitrides and transition metal sulfides,have strong hardness,good wear resistant and super conductivity.However,the electrochemical application of this kind of catalyst is limited because they could not provide a large surface area and small particle size.The high surface area of carbon nanomaterials is favorable for the deposition of transition metal compounds.They can also limit the size of transition metal compounds nanomaterials.As a result,the combination of carbon nanomaterials and transition metal compounds will be an ideal method to get good electrochemical properties.In this paper,the transition metal compounds nano-materials were loaded on the surface of supporting carbon materials and the molybdenum compounds/carbon nanocomposites were established.We employed a variety of methods to analyze composition,structures and morphologies of the as-prepared nanocomposites.L-CySH and glucose were chosed as probe molecules to study the electrochemical activity of molybdenum compounds/carbon nanocomposites.The main contents mentioned in this dissertation are summarized as follow:?1?A novel,facile and effective strategy by using hydrothermal reaction and following high-temperature pyrolysis under the ammonia flow were presented to fabricate the molybdenum nitride nanosheets/N-doped multi-walled carbon nanotubes?MoN/N-MWNTs?hybrid nanocomposite.Taking use of this method,we have successfully synthesized the MoN/N-MWNTs nanocomposites with different loading amounts of MoN.The excellent properties of MoN and N-MWNTs endow the MoN/N-MWNTs nanocomposites with good electrochemical performance.The electrocatalytic oxidation of L-CySH was investigated using cyclic voltammetry and amperometric method at the MoN/N-MWNTs modified electrodes.Compared with N-MWNTs,MoN/N-MWNTs nanocomposites show greater catalytic current and lower overpotential.?2?Ni-doped molybdenum disulfide nanoparticles/reduced graphene oxide?Ni-MoS₂/rGO?composites have been synthesized with a simple and scalable strategy.This material displayed an excellent performance to non-enzymatic glucose detection because of the improved conductivity as well as electron transport rates due to rGO and the highly exposed catalytic sites of Ni-MoS₂.The proportion of Mo and Ni was also optimized and the results indicated that Ni-MoS₂/rGO displayed a rapid response time?< 2 s?,wide linear range?0.005-8.2 mM?,good reproducibility and ideal stability when the molar ratio of Mo to Ni is 1:1.Moreover,the Ni-MoS₂/rGO composite also showed large diffusion coefficient?D = 1.83×10-3 cm2 s-1?and catalytic rate constants?Kcat = 6.26×105 cm3 mol-1 s-1?.