Structure Regulation And Electrochemical Application Of Molybdenum Disulfide Nanostructure

Molybdenum disulfide?MoS₂?is a typical kind of two-dimensional materials with graphene-like structures.It is featured by the unique electronic optical,thermal,and mechanical properties,as well as the large specific surface area.It serves as promising functional materials,for energy storage/conversion,catalysis and sensing.Dealing with the shortcomings of MoS₂ nanostructures,this thesis proposed some rational nanoengineering on MoS₂-based biosensor and electrocatalysts.The in-situ surface-functionalization under microwave irradiation was introduced to one-pot fabricate MoS₂ nanosheets to construct efficient biosensor for cell detection.Meanwhile,V-modification during hydrothermal synthesis was introduced to engineer MoS₂ nanosheets with 1T crystalline structure,resulting in the rich active sites and enhanced conductivity for electrochemical hydrogen evolution reactions?HER?.In-situ surface functionalization by thiourea?TU?reactant was introduced to one-pot fabricate TU-capping MoS₂?TU-Mo S2?nanosheets,and the resulting amino-group terminated surface benefits the immobilization of GE11 peptide that can specifically recognize cancer cells.As expected,the designed TU-MoS₂ showed the sensitive and distinguishing capability for cell detection in electrochemical impedance spectroscopy,featured by a wide linear range?50 106 cells mL-1?with a detection limit of 50 cells mL-1 to human liver cancer cells.This work elucidates an efficient biosensing platform on the basis of surface engineered MoS₂ nanosheets.V-MoS₂ nanosheets were prepared by hydrothermal method,and their crystal structures were changed after acid treatment.Consequently,the catalyst showed metallic features,and the catalytic performance was obviously improved.The relevant mechanism was studied.The optimum reaction conditions were determined by optimizing experimental factors,such as doping amount,solvent ratio,reaction time,and etc.The V-MoS₂ catalyst exhibits an excellent activity for HER in 0.5 M H2SO4 with a current density of 10 mA cm-2 at ? =-154 mV.This performance,should be associated with the enriched active-sites and the improved conductivity after vanadium doping.Additionally,another metal sulfide,Ni3S2,was studied in this work,in which the nanostructures and electrocatalytic behaviors are investigated.In summary,we proposed facile strategies to optimize the nanostructure of MoS₂,with amino-group rich surface,enriched reactive sites,or better conductivity.This work will provide innovation for the development of electrochemical biosensors and electrocatalytic hydrogen evolution.