Preparation Of MoS₂ Micro/Nano-structure By Solvothermal Method And Their Visible Light Photocatalytic Property

Molybdenum disulfide?MoS₂?nano materials have received significant attention recently due to potential applications in?optical?electronics and other fields.The morphology and structure of Mo S₂ nano-materials prepared under different methods and conditions have great differences,which affect the purity,crystal quality and photocatalytic activity of MoS₂.Here we show that Mo S₂ nano-materials canbeprepared by a facile hydrothermal method and a hot-injection method respectively.This article has developed a series of researches based on the synthesis and properties of MoS₂ nano-materials,the specific work are as follows:1.Firstly,nano-sized MoS₂ materials are prepared by using sodium molybdate?Na₂Mo O₄·2H₂O?as molybdenum source and thiourea?CS?NH₂?₂?as sulfur source,and then exploring the effect of adding different types of surfactants on the structure and catalytic impact of performance.MoS₂ samples with different morphologies and structures are hydrothermally synthesized with six different types of surfactants,these samples aretested by XRD,EDS,Mapping and SEM to explorethe structure and appearance and analyzed the formation of the mechanism.The results show that different surfactants all regulate the morphology and structure of MoS₂ nano-materials in different aspects and find that the nonionic surfactant polyvinylpyrrolidone?PVP?plays a key role in forming Mo S₂ nanosheets with a small amount of layers.MoS₂ particles are most obviously modified by the addition of3×10^-3mol/L PVPat molybdenum-sulfur ratio of 1:3,PH=1,250°C,and 24 h.Secondly,the photocatalytic degradation of RhB dyes by surfactant-assisted hydrothermal synthesis of MoS₂ nanospheres are studied.The degradation efficiencies of PVP,SDS and CTMAB for RhB are 93.2%,83.1%and 71.1%,respectively?the reaction time w as 60 min?,the catalytic kinetic constants k are 0.04491 min^-1,0.02971 min^-1and 0.02085 min^-1,respectively.2.A few layers of MoS₂ nanosheets are prepared by thermal injection by using molybdenum acetylacetonate?Mo O₂?acac?₂?as the molybdenum source,dodecanethiol(C₁₂H₂₆S)as the sulfur source,and organic solvents such as oleylamine,oleic acid and octadecene as the reaction solvent.The appearance,structure,and numbers of layer of MoS₂ nanosheets are revealed by XRD,TEM,HRTEM,and Raman.The effects of different reaction temperature,reaction time and type of sulfur source on the preparation of MoS₂ nanosheets are explored in order to find the optimal process for preparing few nanolayers.It is found that 1³ layers of2H-MoS₂ nanosheets can be prepared under the optimal reaction conditions of 270^oC,30 min,Mo:S=1:3,proper surface ligand ratio and the timing of S source injection,which has a good stability.The photocatalytic degradation rate of RhB dyes by a few layers MoS₂ nanosheets prepared by the hot injection method is 92.6%?reaction time is 30 min?,and the k value is0.08851 min^-1.3.Using glucose as carbon source,sodium molybdate as molybdenum source and thiourea as sulfur source,MoS₂/amorphous carbon nanocomposites?MoS₂/AC?are prepared by hydrothermal method.Analyzing the effects of different concentrations of C sources and reaction temperatures on the growth of Mo S₂/AC composites.The results show that with the increase of the concentration of glucose in the reaction system,the spherical particle size of MoS₂/AC increases,but the size is not uniform;as the growth temperature gradually increases to 200^oC,the spherical particle size of Mo S₂/AC becomes smaller,and the specific surface area becomes larger and larger.Therefore,at the studied three temperatures,the optimal temperature for growth is 200^oC.Finally,the photocatalytic performance of sample0.2-MoS₂/AC is investigated,and its k value is 0.00914 min^-1.