Synthesis,heteroatom Doping And Sensitive Detection Of Sulfur Quantum Dots With High Luminous Efficiency

Quantum dot is a promising material because of its unique three-dimensional quantum confinement,caused by its unique photophysical and photochemical properties.Therefore,they can be applied to biological imaging,lasers,solar cells,light-emitting diodes and other fields.However,most high-performance quantum dots(including CdS,CdSe,CdTe,HgTe,and PbSe)and their hybrid structures are limited by the toxicity of metal elements such as Cd,Hg and Pb.The inherent toxicity of traditional heavy metal-based quantum dots hinders their application prospects.In order to solve the toxicity problem,many quantum dots without metal elements have been developed to meet the new demand of obtaining the next generation of green nanomaterials.High-quality pure element quantum dots show low toxicity,excellent solubility and stable photoluminescence,which attract the attention of researchers.Typical examples of metal-free quantum dots include carbon dots,graphene quantum dots,black phosphorus quantum dots and silicon quantum dots,which have been widely studied.However,there is a lack of related research on sulfur quantum dots which show different luminescence properties from bulk materials in quantum size.Sulfur is extremely abundant in the earth and the 14 th richest element in the earth's crust.It is widely used in sulfuric acid production,lithium-sulfur batteries,sulfur modified polymers and organic conversion materials.As a single-element nanomaterial,sulfur quantum dots have the characteristics of no heavy metals,no pollution,easily available raw materials,excellent biocompatibility,etc...They are considered superior to traditional compound semiconductor nanocrystals in practical applications.At present,the research field of sulfur quantum dot luminescent materials is faced with several urgent problems.Firstly,there is no unified conclusion about the photoluminescence mechanism under the quantum size effect;secondly,the fluorescence performance and reaction rate of sulfur quantum dots are not superior to those of other quantum dots;thirdly,the work of doping other elements to modify the photoluminescence properties of sulfur quantum dots is relatively lacking.In recent years,research teams at home and abroad have adopted different strategies to solve the above problems.Based on these different strategies,this paper further explores sulfur quantum dot luminescent materials,which adopts some methods to improve the synthesis strategy of fluorescent sulfur dots and provides some ideas for exploring sulfur quantum dot luminescent materials doped with elements.