Fabrication Of Molybdenum Sulfide/Molybdenum Oxide Based Two Dimensional Materials And Their Applications

Molybdenum is a kind of typical transition metal element with abundant reserves on the earth.Molybdenum Oxide,Molybdenum disulfide have drawn much attention due to their unique physical and chemical properties.For instance,the edge sites of layer Mo S₂ show high hydrogen evolution reaction?HER?catalytic activity,which made Mo S₂ a promising catalyst in HER.Molybdenum oxide owns to its stable physical structure and special bad gap structure,possessing great application potentials in energy storage and energy conversion.Although both of them are low in cost and outstanding in properties,there are still some limitations.The catalytic activity of per active sites in Mo S₂ are still low,for example,and the conductivity of Mo O₃is out of satisfied,which will narrow their further application.Bearing these in mind,efforts has been applied to optimize the properties of Mo S₂ and Mo O₃.Main research contents are described as follows:?1?One pot synthesis of single Cu atom doping 1T defective Mo S₂ with enhanced hydrogen evolution reactionIn this work,we successfully synthesized defective metallic 1T phase Mo S₂ with single Cu atom doping?Cu@Mo S₂?through a simple on-pot hydrothermal method,which has shown excellent hydrogen evolution reaction?HER?catalytic ability.The reaction mechanism and optimized Cu doping amount was then investigated.The high catalytic performance of the catalyst can be ascribed to several reasons,which includes that metallic phase possesses high conductivity,doping of single Cu atom can increase the surface electron density of Mo S₂ which can improve the catalytic ability of active sites,defects can supply more active sites.Finally,Cu@Mo S₂ shows outstanding HER performance due to the synergistic effect of single atom doping,defects and 1T metallic phase.The synthesized Cu@Mo S₂ has narrowed the gap between precious and nonprecious materials in HER,which exhibits a promising application prospect and a new strategy in enhancing the catalytic ability of the HER catalyst.?2?Preparation of Mo O@MXene with in-situ etching method and its applicationIn this work,we provided a new in-situ etching method to prepare MXene.During the etching process,Mo O³⁺can interact to MXene forming Mo O@MXene structure.Without harmful acid reactants involved,aforementioned in-situ method greatly improved the safety of MXene preparation process compared with traditional methods.Besides,Mo O³⁺can protect MXene from oxidized.To invest the application abilities of the sample,electrocatalytic nitrogen reduction reaction and photothermal conversion reaction were conducted.Mo O@MXene shows enhanced nitrogen reduction reaction catalytic ability due to the existence of Mo element.In addition,Mo O@MXene shows localized surface plasmon resonance in near infrared area due to ionic interaction and electron transfer,which made Mo O@MXene a promising candidate in photothermal conversion.?3?Fabrication of amorphous Mo O_3-x@MXene heterostructure and its application in lithium storageIn this work,defective amorphous Mo O_3-x@MXene heterostructure was obtained by thermal treatment with Mo O@MXene.Then it was demonstrated that existence of O defects can stabilize the both component of the heterostructure.After the electrochemical measurement,Mo O_3-x@MXene shows extremely high columbic efficiency,excellent long-term stability and a lower redox potential as lithium ion battery anode material,which means great energy storage properties.All of these advantages can be ascribed to the existence of Mo O_3-x and the stable heterostructure.In a word,our research has shown a new way to improve the energy storage ability of Mo O₃ based materials.