Synthesis And Properties Of Luminescent Molybdenum Disulfide Quantum Dots

Due to its similar structure and properties to graphene,molybdenum disulfide has become a hot research focus in current research and is widely used in many fields such as hydrogen evolution catalysis,energy storage,and optoelectronic devices.The molybdenum disulfide quantum dots has received a great deal of attention,because of nano-size effect,which has more unique magnetic,electrical and optical properties.Although the research on molybdenum disulfide quantum dots has made great progress,its related research is still very limited,and it needs to be developed in terms of material preparation,property research,and application exploration.This dissertation uses liquid phase ultrasonic stripping and hydrothermal method to prepare MoS₂.The influences of a series of hydrothermal reaction conditions on the luminescence properties of molybdenum disulfide were investigated.And the applications of molybdenum disulfide in metal ion probes and the photocatalytic degradation of Rhodamine B were explored.The main results are as follows:(1)The luminescence performance of MoS₂synthesized by liquid phase ultrasonic stripping and hydrothermal method was compared.The MoS₂synthesized by liquid phase ultrasonic stripping has no fluorescence performance because of large particle size and MoS₂synthesized by environmentally friendly and simple hydrothermal method has excellent luminescence performance.Under irradiation of ultraviolet light,it emits baby blue light,and has the excitation-dependent photoluminescence phenomenon.By studying the influence of related conditions of hydrothermal reaction on the luminescence properties of MoS₂,it showed when the temperature is 180?,for 36 h,filling degree of 80%,and S element is a little too much,the luminescence performance of MoS₂prepared at the conditions is best.The photoluminescence results reveal that the emission intensity is significantly enhanced when the surfactant is citric acid.(2)The MoS₂quantum dots synthesized by hydrothermal method have obvious response to Cu²⁺in aqueous solution,and a good linear regression relation is presented in a wide range of concentration(3.9?M-125?M).This method is low cost and easy to operate,so MoS₂quantum dots have the potential to be applied in the field of metal ion fluorescent probes.(3)Rhodamine B solution was degraded under the catalysis of MoS₂quantum dots,and the degradation rate was 17.7%after 3h reaction.Meanwhile,under the catalysis of the citric acid-assisted MoS₂quantum dots,the photocatalytic degradation rate was 24.7%,which was significantly increased by about 40%.It indicates the MoS₂quantum dots synthesized by hydrothermal method have catalytic ability.