Research On The Fabrication Of MoS₂/N-CDs Nanocomposites And Its Photoelectrochemical Properties

Photoelectric chemistry is mainly obtained through the mutual transformation of the photoexcitation source and the electrical signal,and the light source is applied to the photoelectric material,then it is displayed in the form of electrical signals.Of course,the photoelectric material as the basis of this method is also the object of this study.Because the photoelectric analysis method has many characteristics such as high sensitivity,good selectivity,low cost,and so on,it is widely used in the field of clinical analysis and detection of pollutants in the environment.In this paper,nanomaterials,photoelectrochemical analysis and semiconductor materials will be combined to study the photoelectric properties.The the main content is as follows:1.Preparation of molybdenum disulfide by ultrasonic stripping and hydrothermal synthesis of carbon dots composites and its photoelectric effectIn this chapter,natural soybean meal is used as the basic raw material,nitrogen-doped carbon quantum dots are synthesized by a one-step hydrothermal method.Where soybean meal is used as a carbon source and the solvent is water.The carbon dots were characterized by high resolution transmission electron microscopy(HRTEM)images and energy dispersive spectroscopy(EDS).The results show that its size is about 5 nm.Its optical properties were studied by fluorescence(FL)and UV-vis spectra.From the energy level point of view,the few layer of molybdenum disulfide broadband is 1.3 eV-1.9 eV,which is superior semiconductor material.The carbon point is a good sensitizer,greatly promoted the photoelectric effect of less layer molybdenum disulfide.In this chapter,the photoelectric properties of the carbon quantum dot and the molybdenum disulfide complex are studied,and the influence factors of the photoelectric effect from the angle of the offset voltage and the modified quantity are analyzed.The possible mechanism is also described in detail later.2.Preparation of molybdenum disulfide synthesized by intercalation and microwave synthesis carbon dots composites and its photoelectric effectIn this chapter,citric acid is used as the basic raw material,a nitrogen-doped carbon quantum dot with excellent fluorescence is rapidly synthesized by a one-step microwave method.Here,citric acid is used as a carbon source,ethylenediamine is used as a dispersant and a modifier,and water is used as a solvent.The carbon dots obtained were characterized by high resolution transmission electron microscopy(HRTEM)images and energy dispersive spectroscopy(EDS).The results show that its size is about 5-10 nm.Its optical properties were studied by fluorescence(FL)and UV-vis spectra.The method uses the programmed heating of the microwave reactor to make the organic material(here referred to as the carbon source citric acid)pyrolyzed at high temperature to obtain the carbon dots.By this heating method,bumping of the reaction liquid can be avoided and the polymerization which has not completely reacted can be further carbonized.And the energy of the electromagnetic wave generated by the microwave oven directly acts on the organic molecules to achieve the purpose of high-temperature pyrolysis.Microwave method as a commonly used experimental research method,its advantage is fast,easy to operate.And n-butyllithium,as a good intercalation agent for intercalation and exfoliation of layered materials,has also become an internationally recognized research topic,a single layer of molybdenum disulfide is also a semiconducting material with a 1.9 eV bandgap,with good optoelectronic effects.This thesis also studies the optoelectronic properties of the complexes of carbon quantum dots and monolayer molybdenum disulfide.The optimal amount of molybdenum disulfide is discussed and its photoelectric stability is discussed.In this paper,using the natural soybean powder and citric acid as the carbon source,by hydrothermal synthesis and microwave were synthesized through these two kinds of common nitrogen doped carbon quantum dots(N-CDs).And carries on the comparison to these two kinds of synthesis methods.In terms of choice of carbon source is the use of the available soybean meal and citric acid,raw material is cheap.On the synthesis method of using one-step hydrothermal and microwave synthesis has strong fluorescence properties of nitrogen doped carbon quantum dots.Ultraviolet and fluorescence characterization of preliminary demonstrates the advantages and disadvantages of the two methods,and the carbon particle size are 2 to 5 nm.Ultrasonic liquid stripping and n-butyl lithium intercalating stripping are used to prepare few-layer molybdenum disulfide.The complex is formed by coupling the carbon quantum dots with less layer molybdenum disulfide.The photoelectric properties of MoS2/N-CDs complex are mainly studied.And the influence of different molybdenum disulfide modification conditions on its photoelectric effect is studied,and the photoelectrochemical reaction mechanism is preliminarily discussed.