CN113145151B - Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof - Google Patents

Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof Download PDF

Info

Publication number
CN113145151B
CN113145151B CN202110134544.7A CN202110134544A CN113145151B CN 113145151 B CN113145151 B CN 113145151B CN 202110134544 A CN202110134544 A CN 202110134544A CN 113145151 B CN113145151 B CN 113145151B
Authority
CN
China
Prior art keywords
gqds
cds
catalyst
preparation
modified
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110134544.7A
Other languages
Chinese (zh)
Other versions
CN113145151A (en
Inventor
左宁
张梦竹
孙梦
马莹莹
李书珍
王磊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Institute of Technology
Original Assignee
Shanghai Institute of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Institute of Technology filed Critical Shanghai Institute of Technology
Priority to CN202110134544.7A priority Critical patent/CN113145151B/en
Publication of CN113145151A publication Critical patent/CN113145151A/en
Application granted granted Critical
Publication of CN113145151B publication Critical patent/CN113145151B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/24Nitrogen compounds
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00Catalysts, in general, characterised by their form or physical properties
    • B01J35/30Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/39Photocatalytic properties
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/30Treatment of water, waste water, or sewage by irradiation
    • C02F1/32Treatment of water, waste water, or sewage by irradiation with ultraviolet light
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00Nature of the contaminant
    • C02F2101/30Organic compounds
    • C02F2101/308Dyes; Colorants; Fluorescent agents
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00Nature of the contaminant
    • C02F2101/30Organic compounds
    • C02F2101/40Organic compounds containing sulfur
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2305/00Use of specific compounds during water treatment
    • C02F2305/10Photocatalysts
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00Technologies for wastewater treatment
    • Y02W10/30Wastewater or sewage treatment systems using renewable energies
    • Y02W10/37Wastewater or sewage treatment systems using renewable energies using solar energy

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Catalysts (AREA)

Abstract

The invention relates to a modified N-GQDs @ CdS nano catalyst and preparation and application thereof. The N-GQDs @ CdS nano catalyst takes CdS as a core, N-GQDs grow on the surface of the CdS as the core, the N-GQDs and the CdS are connected through a covalent bond, and the N-GQDs are nitrogen element doped graphene quantum dots. The preparation method specifically comprises the following steps: (a) Dissolving citric acid and ammonium carbonate in water, performing ultrasonic dispersion, transferring to a reactor for hydrothermal reaction, and sequentially cooling, rotary steaming and drying to obtain N-GQDs; (b) Dissolving the N-GQDs obtained in the step (a) in water, adding cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide, mixing, performing ultrasonic dispersion, transferring to a reactor for hydrothermal reaction, and then sequentially cooling, washing and drying to obtain N-GQDs @ CdS. Compared with the prior art, the photocatalyst can expand the light absorption range, is beneficial to hole-electron separation, can improve the catalytic efficiency, and has good degradation capability on methylene blue and methyl orange under the condition of ultraviolet light.

Description

Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof
Technical Field
The invention belongs to the technical field of photocatalysis, and particularly relates to a modified N-GQDs @ CdS nano-catalyst, and preparation and application thereof.
Background
With the development of global society and industrial progress, environmental issues are becoming important matters of social widespread concern, wherein water pollution is becoming serious. At present, organic dye wastewater becomes one of main water pollution sources, and the wastewater has the characteristics of large water quantity, high concentration, complex components, deep chromaticity, difficult degradation and the like. Methylene blue and methyl orange are important organic chemically synthesized cationic dyes which are widely applied in industry, but have toxic, carcinogenic, teratogenic and mutagenic effects and can inhibit photosynthesis of plants in an aquatic system; the COD value is high, which can lead to eutrophication of the water body. Common treatment methods include adsorption method, membrane separation method, common oxidation method, biological method and the like, but the methods have the defects of complex process flow, high equipment requirement, high cost, damage to microenvironment and the like. In recent years, photocatalytic degradation of toxic and harmful pollutants by semiconductor materials has become an important research direction. The photocatalysis technology has the advantages of low energy consumption, simple and convenient operation, mild reaction conditions and no secondary pollution, and can effectively convert organic pollutants into inorganic micromolecules to achieve the aim of complete inorganization.
The semiconductor photocatalyst is TiO 2 Silver-based semiconductors, tungsten-based semiconductors, znO, cdS and other semiconductor materials as a general term of substances for photocatalytic degradation. The photocatalyst mainly utilizes the fact that the energy of the emission of sunlight and ultraviolet light is larger than the energy gap of a semiconductor material, and valence band electrons in the semiconductor are excited to jump to a high-energy conduction band during illumination, so that electrons and holes are left in the valence band, and a part of photogenerated electrons (e) are generated - ) And a cavity (h) + ) Diffusing to the surface of the photocatalyst and finally undergoing redox reaction with electrons or electron acceptors adsorbed on the surface of the photocatalyst, thereby forming a series initiated by active groups of the photocatalystThe photocatalyst has the advantages of proper energy band potential, high chemical stability, no toxicity, no harm, higher photoelectric conversion efficiency, low cost, high activity and the like, can become an irreplaceable preferred material in chemical production and is mainly applied to the fields of organic synthesis, catalytic chemistry, environmental management, electrochemistry, biochemistry and the like.
However, the conventional photocatalyst is generally a single photocatalyst, and photo-generated electrons and holes generated in the process of illumination are easily self-recombined, which can reduce the number of the photo-generated electrons and holes, further cause the loss of active sites on the surface of the catalyst, reduce the photocatalytic efficiency, and hinder the further development of the photocatalyst. The modified graphene quantum dot integrates quantum confinement, size effect and edge effect, has the advantages of good water solubility, low biotoxicity, excellent chemical inertness, stable fluorescence, easy surface modification performance, excellent luminescence property, adjustable band gap and the like, and has wide application prospect in the fields related to chemical sensing, biological imaging, medical treatment and energy. Therefore, it is imperative to modify the traditional photocatalyst to prepare a high-efficiency photocatalyst, and how to improve the effective active sites by the mutual combination of the modified photocatalyst or multiple photocatalysts, reduce the recombination rate of the photogenerated electrons and holes generated in the illumination process, and improve the photocatalytic efficiency has become a hotspot of research at present.
Patent CN111682222A discloses a preparation method of a Pt-CdS-nitrogen doped graphene quantum dot composite material and a catalytic application thereof. The Pt-CdS-nitrogen doped graphene quantum dot composite material is prepared from soluble cadmium salt, thiourea, citric acid and urea serving as raw materials by a solvothermal method, and is in a nanowire shape. The invention relates to a method for preparing a composite material, which comprises the following steps of (1) preparing cadmium sulfide into a nano-wire shape, wherein the cadmium sulfide prepared by the invention is in a spherical shape, so that the specific surface area is greatly increased, the transmission rate of photogenerated electrons and holes on the surface of the cadmium sulfide is increased during illumination, and the photocatalytic efficiency is favorably increased, (2) preparing N-GQDs by the patent requires reaction for 48 hours, but the method only requires 4 hours to complete the preparation, 3. The composite material prepared by the patent is prepared in a subsection way, and the steps are complicated, but the experiment of the invention is completed in a one-pot hydrothermal method, so that the invention is convenient and quick, 4. The composite material prepared by the patent is used for electrochemistry, and how the photocatalytic efficiency of the material is in photocatalysis can not be known, and the catalyst can be used as a photocatalyst and can be used for degrading organic dyes, and is completely two different applications.
Disclosure of Invention
The invention aims to provide a modified N-GQDs @ CdS nano-catalyst and preparation and application thereof.
The purpose of the invention is realized by the following technical scheme:
a modified N-GQDs @ CdS nano-catalyst takes CdS as a core, N-GQDs grow on the surface, namely cadmium sulfide is the core, the N-GQDs load the surface of the CdS, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through covalent bonds, wherein, GQDs represents Graphene quantum dots (Graphene quantum dots), the N-GQDs are nitrogen-doped Graphene quantum dots, the specific surface area of spherical CdS is greatly increased, the rate of transferring photo-generated electrons and holes on the surface of cadmium sulfide is increased during illumination, and the photocatalytic efficiency is increased.
A preparation method of the modified N-GQDs @ CdS nano-catalyst specifically comprises the following steps:
(a) Dissolving citric acid and ammonium carbonate in water, performing ultrasonic dispersion, transferring to a reactor for hydrothermal reaction, and sequentially cooling, rotary steaming and drying to obtain N-GQDs presenting blue fluorescent response;
(b) Dissolving the N-GQDs obtained in the step (a) in water, adding cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide, mixing, ultrasonically dispersing, transferring to a reactor for hydrothermal reaction, and then sequentially cooling, washing and drying to obtain N-GQDs @ CdS, wherein the polyvinylpyrrolidone has a cross-linking polymerization effect, N-GQDs quantum dots can be better loaded on the surface of cadmium sulfide, the dimethyl sulfoxide has a sulfur source providing effect, and the CdS is obtained by reacting with the cadmium acetate, and the specific reaction process is as follows: in a hydrothermal reaction kettle, cadmium acetate and dimethyl sulfoxide react under the conditions of high temperature and high pressure to generate cadmium sulfide, and N-GQDs grow on the surface of the cadmium sulfide under the action of polyvinylpyrrolidone and are finally anchored on the surface of the cadmium sulfide.
In the step (a), the molar ratio of citric acid to ammonium carbonate is 1:3, and the nitrogen-doped graphene quantum dots generated in the ratio have uniform particle size, uniform distribution and good water solubility.
In the step (a), the power of the ultrasonic wave is 150W, and the time of the ultrasonic wave is 0.1h, so that the reaction raw materials are uniformly dispersed to fully react.
In the step (a), the temperature of the hydrothermal reaction is 140-180 ℃, preferably 160 ℃, and the time is 2-6h, preferably 4h.
In the step (b), the adding amount ratio of N-GQDs, cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide is (0.01-0.03) g to (0.133) g and (0.06-0.12) g to 40mL.
In the step (b), the addition ratio of N-GQDs, cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide is preferably 0.02g.
In the step (b), the power of the ultrasound is 150W, the time of the ultrasound is 0.5h, the aim is to disperse the reaction raw materials uniformly so as to fully react.
In the step (b), the temperature of the hydrothermal reaction is 160-180 ℃ and the time is 12-18h.
In the step (b), the temperature of the hydrothermal reaction is 180 ℃ and the time is 15h.
In step (b), the reaction mixture was cooled to room temperature, washed with absolute ethanol, and dried at 60 ℃ overnight.
An application of the N-GQDs @ CdS nano-catalyst in degrading dye wastewater. Under the irradiation of ultraviolet light, the degradation effect of N-GQDs @ CdS on methylene blue and methyl orange is very excellent.
The invention provides a N-GQDs @ CdS nano-catalyst, and adopts a one-pot hydrothermal method, the performance of the catalyst is regulated and controlled by controlling the reaction time, the reaction temperature, the using amount of a precursor of the N-GQDs and the using amount of polyvinylpyrrolidone, so that the N-GQDs can be stably loaded on the surface of CdS under a proper condition, and finally the N-GQDs @ CdS catalyst is obtained, and the N-GQDs in the catalyst can emit blue fluorescence under 365 nm. The invention introduces N-GQDs into the CdS surface of the carrier, which can expand the light absorption range, is beneficial to the separation of holes and electrons, can improve the catalytic efficiency, can stably transmit electrons during the ultraviolet irradiation, and has good catalytic activity on methylene blue and methyl orange under the ultraviolet condition, probably because the synergistic action between N and GQDs leads to the increase of partial defects on the CdS surface of the catalyst, thereby forming a lower energy gap, and electrons can be transferred and retained under the ultraviolet light, thereby improving the catalytic efficiency. Compared with the traditional single N-GQDs and CdS, the N-GQDs @ CdS nano-catalyst obtained by the method overcomes the problems of instability and CdS light defects of the single catalyst, remarkably improves the catalytic efficiency, and expands the application of the N-GQDs @ CdS nano-catalyst in photocatalytic degradation of organic pollutants. According to the invention, through selecting the used raw materials, temperature and other conditions, the obtained final product is used for degrading two pollutants under a certain illumination condition, and the difference of the treatment effects of different catalysts prepared under different material doping conditions on the pollutants is explored, so that more ideas are provided for degrading dye wastewater.
Drawings
FIG. 1 is an infrared spectrum of N-GQDs @ CdS nanocatalyst in example 1;
FIG. 2 is a Raman spectrum of the N-GQDs @ CdS nanocatalyst in example 1;
FIG. 3 is SEM electron micrograph of N-GQDs @ CdS nanocatalyst of example 1 at 10.0 μm;
FIG. 4 is SEM electron micrograph of N-GQDs @ CdS nanocatalyst of example 1 at 1.00 μm;
FIG. 5 is a graph showing the substantial comparison between the non-fluorescence of N-GQDs under natural light irradiation and the blue fluorescence under 365nm light irradiation in example 1;
FIG. 6 is a graph of the efficiency of N-GQDs @ CdS nanocatalyst in example 3 for degrading methylene blue and methyl orange as a function of time and light conditions;
FIG. 7 is a graph showing the efficiency of N-GQDs nanocatalyst degrading methylene blue in comparative example 1 as a function of time and light conditions;
FIG. 8 is a graph showing the efficiency of CdS nanocatalyst degrading methylene blue in comparative example 2 as a function of time and light conditions.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments.
The raw materials used in the invention can be purchased in the market, are analytically pure, do not need further treatment and can be directly used, wherein, the used citric acid, ammonium carbonate, cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide are purchased from chemical reagents of national drug group, inc.
Example 1
A modified N-GQDs @ CdS nano catalyst takes CdS as a core, N-GQDs grow on the surface, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through a covalent bond. The preparation method comprises the following steps of preparing raw materials, wherein the raw materials comprise 0.21g of citric acid, 0.237g of ammonium carbonate, 0.133g of cadmium acetate, 0.06g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide. The method comprises the following specific steps:
a preparation method for preparing N-GQDs @ CdS nano-catalyst based on controlling hydrothermal reaction time, temperature, N-GQDs and polyvinylpyrrolidone dosage comprises the following specific steps:
(1) Weighing 0.21g of citric acid and 0.237g of ammonium carbonate, dissolving in 40mL of deionized water, ultrasonically dispersing for 0.1h at 150W, transferring into a 50mL hydrothermal reaction kettle, putting the reaction kettle into a drying box, keeping the temperature at 160 ℃ for 4h, cooling, performing rotary evaporation, and drying (cooling to room temperature, wherein the whole rotary evaporation process is troublesome, firstly dialyzing, then performing rotary evaporation, and finally drying at 60 ℃ for 12h, the same below), preparing N-GQDs capable of emitting blue fluorescence under 365nm irradiation, and irradiating the N-GQDs under natural light, wherein the compound does not emit fluorescence, as shown in the right graph in figure 5, and under 365nm light, the compound emits blue fluorescence, as shown in the left graph in figure 5;
(2) Putting 10mg of the prepared N-GQDs into a beaker, adding 0.133g of cadmium acetate, 0.06g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide into the beaker, ultrasonically dispersing for 0.5h at 150W, transferring the beaker into a 50mL hydrothermal reaction kettle, preserving the temperature for 15h at 180 ℃, cooling to room temperature, washing with absolute ethyl alcohol, and drying at 60 ℃ overnight to prepare the N-GQDs @ CdS nano catalyst. An infrared spectrogram and a Raman spectrogram of the catalyst are respectively shown in fig. 1 and 2, characteristic peaks 1100C-N single bond and C-C single bond in the infrared spectrogram indicate that nitrogen is successfully doped into graphene quantum dots, 1400C = S bond indicates that the nitrogen-doped graphene quantum dots are connected with cadmium sulfide by C = S covalent bond, an electron micrograph of the catalyst is shown in fig. 3 and 4, as can be seen from fig. 3, a layer of coating matter is arranged on the surface of the cadmium sulfide, the nitrogen-doped graphene quantum dots loaded on the surface of the cadmium sulfide under the action of polyvinylpyrrolidone are arranged on the cadmium sulfide, and as can be seen from fig. 4, cdS particles are full and are basically round, and the particle size is 803-894nm.
The catalyst is used for catalyzing methylene blue and methyl orange, and specifically comprises the following components: respectively putting 20mgN-GQDs @ CdS nano-catalysts into 150mL quartz tubes, respectively adding 10mg/L methylene blue and methyl orange solutions into the two quartz tubes, respectively adding the two rotors into the two quartz tubes, opening a photocatalytic reactor, stirring for 90min under a dark condition to achieve adsorption-desorption balance, opening a water circulation system, carrying out photocatalytic degradation under the condition of a 500w mercury lamp, taking samples every 10min, filtering by using a 0.22 mu m microporous filter head to remove residual catalysts, and then measuring absorbance in an ultraviolet spectrophotometer. The degradation efficiency calculation formula is as follows: eta = A t /A 0 Eta: degradation efficiency; a. The t : absorbance at a certain time: a. The 0 : initial absorbance (same below). The degradation efficiency and the photocatalytic efficiency are shown in Table 1, and the degradation efficiency of N-GQDs @ CdS nano-catalyst to methylene blue and methyl orange under the ultraviolet light condition is determinedTherefore, the following steps are carried out: when the content of polyvinylpyrrolidone and N-GQDs is insufficient, the N-GQDs cannot be completely loaded on the surface of CdS and cannot provide enough effective active sites, so that the degradation efficiency of methylene blue and methyl orange is not high.
Example 2
A modified N-GQDs @ CdS nano catalyst takes CdS as a core, N-GQDs grow on the surface, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through a covalent bond. The preparation method comprises the following steps of preparing raw materials including 0.21g of citric acid, 0.237g of ammonium carbonate, 0.133g of cadmium acetate, 0.08g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide. The method comprises the following specific steps:
(1) Weighing 0.21g of citric acid and 0.237g of ammonium carbonate, dissolving in 40mL of deionized water, ultrasonically dispersing for 0.1h at the power of 150W, transferring into a 50mL hydrothermal reaction kettle, putting the reaction kettle into a drying box, preserving heat for 4h at 160 ℃, cooling, rotary evaporating and drying to prepare blue fluorescent N-GQDs;
(2) And (2) putting 20mg of the prepared N-GQDs into a beaker, adding 0.133g of cadmium acetate, 0.08g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide into the beaker, ultrasonically dispersing for 0.5h at 150W, transferring into a 50mL hydrothermal reaction kettle, preserving the temperature for 15h at 180 ℃, cooling to room temperature, washing with absolute ethyl alcohol, and drying at 60 ℃ overnight to prepare the N-GQDs @ CdS nano catalyst.
The catalyst is used for catalyzing methylene blue and methyl orange, the degradation efficiency and the photocatalytic efficiency are specifically shown in table 1, and the degradation efficiency of the N-GQDs @ CdS nano catalyst to the methylene blue and the methyl orange under the ultraviolet light condition can be known as follows: when the consumption of the polyvinylpyrrolidone is insufficient, the N-GQDs loaded on the surface of the CdS are easy to fall off and are not enough to provide enough effective active sites, so that the degradation efficiency of the methylene blue and the methyl orange is not high.
Example 3
A modified N-GQDs @ CdS nano catalyst takes CdS as a core, N-GQDs grow on the surface, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through a covalent bond. The preparation method comprises the following steps of preparing raw materials, wherein the raw materials comprise 0.21g of citric acid, 0.237g of ammonium carbonate, 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide. The method comprises the following specific steps:
(1) Weighing 0.21g of citric acid and 0.237g of ammonium carbonate, dissolving in 40mL of deionized water, ultrasonically dispersing for 0.1h at the power of 150W, transferring into a 50mL hydrothermal reaction kettle, putting the reaction kettle into a drying box, preserving heat for 4h at 160 ℃, cooling, rotary evaporating and drying to prepare blue fluorescent N-GQDs;
(2) And (2) putting 20mg of the prepared N-GQDs into a beaker, adding 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide into the beaker, ultrasonically dispersing for 0.5h at 150W, transferring into a 50mL hydrothermal reaction kettle, preserving the temperature for 15h at 180 ℃, cooling to room temperature, washing with absolute ethyl alcohol, and drying at 60 ℃ overnight to prepare the N-GQDs @ CdS nano catalyst.
The catalyst is used for catalyzing methylene blue and methyl orange, the degradation efficiency and the photocatalytic efficiency are specifically shown in table 1, the change condition of the degradation efficiency along with time is shown in fig. 6, and the degradation efficiency of the N-GQDs @ CdS nano catalyst on the methylene blue and the methyl orange under the ultraviolet light condition can be known: when the amounts of the polyvinylpyrrolidone and the N-GQDs are sufficient, the N-GQDs are loaded on the surface of CdS stably enough to provide active sites which are effective enough, so that the degradation efficiency of methylene blue and methyl orange is better.
Example 4
A modified N-GQDs @ CdS nano catalyst takes CdS as a core, N-GQDs grow on the surface, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through a covalent bond. The preparation method comprises the following steps of preparing raw materials, wherein the raw materials comprise 0.21g of citric acid, 0.237g of ammonium carbonate, 0.133g of cadmium acetate, 0.12g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide. The method comprises the following specific steps:
(1) Weighing 0.21g of citric acid and 0.237g of ammonium carbonate, dissolving in 40mL of deionized water, ultrasonically dispersing for 0.1h at the power of 150W, transferring into a 50mL hydrothermal reaction kettle, putting the reaction kettle into a drying box, preserving heat for 4h at 160 ℃, cooling, rotary evaporating and drying to prepare blue fluorescent N-GQDs;
(2) And (2) putting 30mg of the prepared N-GQDs into a beaker, adding 0.133g of cadmium acetate, 0.12g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide into the beaker, ultrasonically dispersing for 0.5h at 150W, transferring into a 50mL hydrothermal reaction kettle, preserving the temperature for 15h at 180 ℃, cooling to room temperature, washing with absolute ethyl alcohol, and drying at 60 ℃ overnight to prepare the N-GQDs @ CdS nano catalyst.
The catalyst is used for catalyzing methylene blue and methyl orange, the degradation efficiency and the photocatalytic efficiency are specifically shown in table 1, and the degradation efficiency of the N-GQDs @ CdS nano catalyst to the methylene blue and the methyl orange under the ultraviolet light condition can be known as follows: when the amounts of polyvinylpyrrolidone and N-GQDs are too large, the N-GQDs are easy to agglomerate on the surface of CdS and are difficult to provide enough effective active sites, so that the degradation efficiency of methylene blue and methyl orange is not high.
Example 5
A modified N-GQDs @ CdS nano catalyst takes CdS as a core, N-GQDs grow on the surface, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through a covalent bond. The preparation method comprises the following steps of preparing raw materials including 0.21g of citric acid, 0.237g of ammonium carbonate, 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide. The method comprises the following specific steps:
(1) Weighing 0.21g of citric acid and 0.237g of ammonium carbonate, dissolving in 40mL of deionized water, ultrasonically dispersing for 0.1h at the power of 150W, transferring into a 50mL hydrothermal reaction kettle, putting the reaction kettle into a drying box, preserving heat for 4h at 160 ℃, cooling, rotary evaporating and drying to prepare blue fluorescent N-GQDs;
(2) And (2) putting 20mg of the prepared N-GQDs into a beaker, adding 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide into the beaker, ultrasonically dispersing for 0.5h at the power of 150W, transferring the beaker into a 50mL hydrothermal reaction kettle, preserving the temperature at 180 ℃ for 12h, cooling to room temperature, washing with absolute ethyl alcohol, and drying at 60 ℃ overnight to prepare the N-GQDs @ CdS nano catalyst.
The catalyst is used for catalyzing methylene blue and methyl orange, the degradation efficiency and the photocatalytic efficiency are specifically shown in table 1, and the degradation efficiency of the N-GQDs @ CdS nano catalyst to the methylene blue and the methyl orange under the ultraviolet light condition can be known as follows: when the amount of polyvinylpyrrolidone and N-GQDs is sufficient and the reaction time is insufficient, the N-GQDs cannot be completely loaded on the CdS surface and cannot provide enough effective active sites, so that the degradation efficiency of methylene blue and methyl orange is not high.
Example 6
A modified N-GQDs @ CdS nano-catalyst takes CdS as a core, N-GQDs grow on the surface, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through a covalent bond. The preparation method comprises the following steps of preparing raw materials, wherein the raw materials comprise 0.21g of citric acid, 0.237g of ammonium carbonate, 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide. The method comprises the following specific steps:
(1) Weighing 0.21g of citric acid and 0.237g of ammonium carbonate, dissolving in 40mL of deionized water, ultrasonically dispersing for 0.1h at the power of 150W, transferring into a 50mL hydrothermal reaction kettle, putting the reaction kettle into a drying oven, keeping the temperature for 4h at 160 ℃, cooling, rotary steaming and drying to prepare blue fluorescent N-GQDs;
(2) And (2) putting 20mg of the prepared N-GQDs into a beaker, adding 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide into the beaker, ultrasonically dispersing for 0.5h at 150W, transferring into a 50mL hydrothermal reaction kettle, preserving the temperature for 15h at 160 ℃, cooling to room temperature, washing with absolute ethyl alcohol, and drying at 60 ℃ overnight to prepare the N-GQDs @ CdS nano catalyst.
The catalyst is used for catalyzing methylene blue and methyl orange, the degradation efficiency and the photocatalytic efficiency are specifically shown in table 1, and the degradation efficiency of the N-GQDs @ CdS nano catalyst to the methylene blue and the methyl orange under the ultraviolet light condition can be known as follows: when the hydrothermal reaction temperature is insufficient, the N-GQDs are loaded on the CdS surface unstably and cannot provide enough effective active sites, so that the degradation efficiency of methylene blue and methyl orange is not high.
Example 7
A modified N-GQDs @ CdS nano catalyst takes CdS as a core, N-GQDs grow on the surface, the particle size of the N-GQDs is 3-8nm, the CdS is spherical, the particle size of the CdS is 800-900nm, and the N-GQDs and the CdS are connected through a covalent bond. The preparation method comprises the following steps of preparing raw materials, wherein the raw materials comprise 0.21g of citric acid, 0.237g of ammonium carbonate, 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide. The method comprises the following specific steps:
(1) Weighing 0.21g of citric acid and 0.237g of ammonium carbonate, dissolving in 40mL of deionized water, ultrasonically dispersing for 0.1h at the power of 150W, transferring into a 50mL hydrothermal reaction kettle, putting the reaction kettle into a drying oven, keeping the temperature for 4h at 160 ℃, and then cooling, rotary steaming and drying to prepare blue fluorescent N-GQDs;
(2) And (2) putting 20mg of the prepared N-GQDs into a beaker, adding 0.133g of cadmium acetate, 0.1g of polyvinylpyrrolidone and 40mL of dimethyl sulfoxide into the beaker, ultrasonically dispersing for 0.5h at 150W, transferring into a 50mL hydrothermal reaction kettle, preserving heat for 18h at 180 ℃, cooling to room temperature, washing with absolute ethyl alcohol, and drying at 60 ℃ overnight to prepare the N-GQDs @ CdS nano catalyst.
The catalyst is used for catalyzing methylene blue and methyl orange, the degradation efficiency and the photocatalytic efficiency are specifically shown in table 1, and the degradation efficiency of the N-GQDs @ CdS nano catalyst to the methylene blue and the methyl orange under the ultraviolet light condition can be known as follows: when the amount of polyvinylpyrrolidone and N-GQDs is sufficient and the reaction time is too long, agglomeration can occur between CdS, the load of N-GQDs is influenced, and sufficient effective active sites are difficult to provide, so that the degradation efficiency of methylene blue and methyl orange is not high.
TABLE 1 degradation efficiency summary of N-GQDs @ CdS nanocatalysts prepared in each example and two comparative examples for methylene blue and methyl orange
Figure BDA0002925274470000101
In conclusion, when the molar ratio of citric acid to ammonium carbonate is 1, the addition ratio of the citric acid to the ammonium carbonate is 0.02g to 0.133g.
Comparative example 1
Respectively putting 20mg of N-GQDs (obtained by adopting the preparation step (1) shown in the example 3 as the N-GQDs catalyst) into two 150mL quartz tubes, respectively adding 100mL of 10mg/L of methylene blue and methyl orange solution into the quartz tubes, respectively adding two rotors into the quartz tubes, respectively opening a photocatalytic reactor, stirring for 90min under the dark condition to achieve adsorption-desorption balance, opening a water circulation system at the moment, performing photocatalytic degradation under the condition of a 500w mercury lamp, taking samples every 10min, filtering by using a 0.22 mu m microporous filter head to remove residual catalyst, and then measuring the absorbance in an ultraviolet spectrophotometer, wherein as shown in FIG. 7, the degradation efficiency of 90min methyl orange under the dark condition is 21%, the degradation efficiency of 90min methyl orange under the illumination condition is 64%, the degradation efficiency of 90min methylene blue under the illumination condition is 24%, and the degradation efficiency of 90min methylene blue under the illumination condition is 68%.
Comparative example 2
Respectively putting 20mg of CdS (the CdS catalyst is obtained by the same operation as the preparation step (2) shown in the example 3 except that N-GQDs and polyvinylpyrrolidone are not added) into two 150mL quartz tubes, respectively adding 100mL of 10mg/L methylene blue and methyl orange solution into the CdS catalysts, respectively adding two rotors into the two quartz tubes, opening a photocatalytic reactor, stirring for 90min under a dark condition to achieve adsorption-desorption balance, opening a water circulation system at the moment, performing photocatalytic degradation under the condition of a 500w mercury lamp, taking a sample every 10min, filtering by using a 0.22 mu m microporous filter head to remove residual catalyst, and then performing absorbance measurement in an ultraviolet spectrophotometer, specifically as shown in FIG. 8, wherein the dark efficiency of 90min of methyl orange under the dark condition is 23%, the degradation efficiency of 90min of methyl orange under the illumination condition is 74%, the degradation efficiency of 90min of methylene blue under the dark condition is 27%, and the degradation efficiency of 90min of methylene blue under the illumination is 72%.
Example 8
A modified N-GQDs @ CdS nano-catalyst is prepared by the following preparation method, and the preparation method is the same as the preparation method of the embodiment 3 except that the hydrothermal temperature in the step (1) is 140 ℃ and the time is 6 hours.
Example 9
A modified N-GQDs @ CdS nano-catalyst is prepared by the following preparation method, and the preparation method is the same as the preparation method of the embodiment 3 except that the hydrothermal temperature in the step (1) is 180 ℃ and the time is 2 hours.
The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims (7)

1. The preparation method of the modified N-GQDs @ CdS nano catalyst is characterized in that the catalyst takes CdS as a core, N-GQDs grow on the surface of the CdS as the core and are connected through a covalent bond, the N-GQDs are nitrogen element doped graphene quantum dots, the catalyst is used for catalyzing and degrading methylene blue and methyl orange, and the preparation method specifically comprises the following steps:
(a) Dissolving citric acid and ammonium carbonate in water, performing ultrasonic dispersion, transferring to a reactor for hydrothermal reaction, and sequentially cooling, rotary steaming and drying to obtain N-GQDs;
(b) Dissolving the N-GQDs obtained in the step (a) in water, adding cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide, mixing, ultrasonically dispersing, transferring into a reactor for hydrothermal reaction, and then sequentially cooling, washing and drying to obtain N-GQDs @ CdS;
in the step (a), the temperature of the hydrothermal reaction is 140-180 ℃ and the time is 2-6h.
2. The preparation method of the modified N-GQDs @ CdS nanocatalyst as claimed in claim 1, wherein in step (a), the molar ratio of citric acid to ammonium carbonate is 1:3.
3. The preparation method of the modified N-GQDs @ CdS nano-catalyst as claimed in claim 1, wherein in step (b), the addition ratio of N-GQDs, cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide is (0.01-0.03) g:0.133g (0.06-0.12) g:40mL.
4. The preparation method of the modified N-GQDs @ CdS nanocatalyst as claimed in claim 3, wherein in the step (b), the addition ratio of N-GQDs, cadmium acetate, polyvinylpyrrolidone and dimethyl sulfoxide is 0.02g.
5. The preparation method of the modified N-GQDs @ CdS nano-catalyst as claimed in claim 1, wherein in step (b), the hydrothermal reaction temperature is 160-180 ℃ and the time is 12-18h.
6. The preparation method of the modified N-GQDs @ CdS nano-catalyst as claimed in claim 5, wherein in step (b), the temperature of hydrothermal reaction is 180 ℃ and the time is 15h.
7. The method for preparing the modified N-GQDs @ CdS nanocatalyst as claimed in claim 1, wherein in step (b), cooling to room temperature, washing with absolute ethanol, and drying at 60 ℃ overnight.
CN202110134544.7A 2021-01-30 2021-01-30 Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof Active CN113145151B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110134544.7A CN113145151B (en) 2021-01-30 2021-01-30 Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110134544.7A CN113145151B (en) 2021-01-30 2021-01-30 Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof

Publications (2)

Publication Number Publication Date
CN113145151A CN113145151A (en) 2021-07-23
CN113145151B true CN113145151B (en) 2022-11-15

Family

ID=76879064

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110134544.7A Active CN113145151B (en) 2021-01-30 2021-01-30 Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof

Country Status (1)

Country Link
CN (1) CN113145151B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105013511A (en) * 2015-07-06 2015-11-04 常州大学 Preparation method for cadmium sulfide quantum dot/carbon nanotube photocatalyst taking polyvinylpyrrolidone as dispersant
CN110627046A (en) * 2019-08-28 2019-12-31 广西医科大学附属肿瘤医院 Nitrogen-doped graphene quantum dot and preparation method and application thereof
CN110927238A (en) * 2019-12-12 2020-03-27 山东理工大学 Preparation method and application of sandwich type photoelectrochemical sensor for detecting prostate specific antigen
CN111682222A (en) * 2020-06-17 2020-09-18 宁波大学 Preparation method and catalytic application of Pt-CdS-nitrogen doped graphene quantum dot composite material

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI625377B (en) * 2016-03-21 2018-06-01 國立成功大學 Reaction system and using method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105013511A (en) * 2015-07-06 2015-11-04 常州大学 Preparation method for cadmium sulfide quantum dot/carbon nanotube photocatalyst taking polyvinylpyrrolidone as dispersant
CN110627046A (en) * 2019-08-28 2019-12-31 广西医科大学附属肿瘤医院 Nitrogen-doped graphene quantum dot and preparation method and application thereof
CN110927238A (en) * 2019-12-12 2020-03-27 山东理工大学 Preparation method and application of sandwich type photoelectrochemical sensor for detecting prostate specific antigen
CN111682222A (en) * 2020-06-17 2020-09-18 宁波大学 Preparation method and catalytic application of Pt-CdS-nitrogen doped graphene quantum dot composite material

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
Highly luminescent S, N co-doped graphene quantum dots with broad visible absorption bands for visible light photocatalysts;Qu Dan等;《Nanoscale》;20131007;第2卷(第24期);第12272-12277页 *
One-pot synthesis of N-doped graphene quantum dots as highly sensitive fluorescent sensor for detection of mercury ions water solutions;Yue Yang等;《Materials Research Express》;20190719(第6期);第1-10页 *
水热法制备聚苯乙烯/CdS核壳结构纳米复合颗粒;孙冠华;《材料工程》;20141231(第4期);第89-94页 *
石墨烯量子点/硫化镉纳米复合物的制备及其光催化性质研究;谢关才;《万方学位论文》;20131031;第45-50页 *
类石墨烯相氮化碳的制备和改性以及光催化性能的研究;王来春;《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅰ辑》;20171015;第B014-5页 *

Also Published As

Publication number Publication date
CN113145151A (en) 2021-07-23

Similar Documents

Publication Publication Date Title
Jin et al. Ni, Co-based selenide anchored g-C3N4 for boosting photocatalytic hydrogen evolution
CN102350369B (en) Nitrogen/fluorine-doped titanium dioxide photocatalyst and application thereof in degrading organic pollutants under visible light
CN110252326B (en) Copper tungstate @ zinc oxide composite photocatalyst and preparation method and application thereof
Gao et al. A review on mechanism, applications and influencing factors of carbon quantum dots based photocatalysis
CN108067267B (en) Visible light response cadmium telluride/titanium dioxide Z-type photocatalyst and preparation method and application thereof
CN110721698B (en) Bismuth vanadate/copper vanadate composite photocatalyst and preparation method and application thereof
CN113145138B (en) Thermal response type composite photocatalyst and preparation method and application thereof
CN112642483A (en) N-GQDs-PS @ CdS core-shell nano-catalyst as well as preparation method and application thereof
CN110624595A (en) Calcium-indium-sulfur/titanium carbide photocatalytic composite material and preparation method thereof
CN112774718A (en) Cuprous oxide/tubular graphite-like phase carbon nitride composite catalyst and preparation method and application thereof
CN111530490A (en) Co3O4-TiO2Heterojunction loaded carbon nanotube photocatalytic degradation material and preparation method thereof
CN108686658B (en) C-QDs-Fe2O3/TiO2Composite photocatalyst and preparation method thereof
CN108543542B (en) Preparation method and application of three-dimensional porous composite photocatalyst
CN111468134B (en) 3D flower-shaped Bi2WO6@ CoO heterojunction photocatalyst and preparation method and application thereof
CN110787826B (en) Ag-loaded WO3Nano fiber-porous carbon photocatalysis material and preparation method thereof
CN1915505A (en) Method for preparing high stable, reproducible load type photocatalyst of Nano cadmium sulphide
CN103342402A (en) Method for degrading methylene blue by using nitrogen-doped oxygen vacancy type TiO2 catalyst
CN113769764B (en) CdS/Cu 7 S 4 /CdMoO 4 Preparation method and application of nano heterostructure
CN114011435A (en) Water-soluble silver-indium-sulfur quantum dot photocatalyst and room-temperature preparation method
CN113042079B (en) Modified N, S-GQDs @ CdS nano-catalyst and preparation and application thereof
CN110586060B (en) Composite photocatalyst with oxidation-reduction performance and preparation method thereof
CN103623870B (en) The preparation method of a kind of silver orthophosphate/polyvinyl chloride-based conjugated polyene visible light catalyst
CN113145151B (en) Modified N-GQDs @ CdS nano-catalyst and preparation and application thereof
CN110180557B (en) Ag2S/TiO2Preparation method and application of composite photocatalyst
CN108940348B (en) Silver chromate/sulfur-doped nitrogen carbon Z-type photocatalyst and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant