Disclosure of Invention
Aiming at the problems in the prior art, the invention discloses a low-dimensional self-assembly flower-shaped Cu2Preparation method of O-ZnO catalyst, and flower-like Cu synthesis by hydrothermal method2O or flower-shaped ZnO, then using wet chemical method, centrifugal cleaning with deionized water and alcohol alternatively, drying to obtain low-dimensional self-assembly flower-shaped Cu2An O-ZnO catalyst. The specific scheme is as follows:
low-dimensional self-assembly flower-shaped Cu2Preparation method of O-ZnO catalyst, flower-like Cu2Ultrasonically dispersing O or flower-shaped ZnO in the solution, sequentially adding zinc acetate alcohol solution and lithium hydroxide alcohol solution or sequentially adding lithium hydroxide, copper chloride and ascorbic acid, reacting, cooling to room temperature, taking out, centrifugally cleaning and drying to obtain the low-dimensional self-assembled flower-shaped Cu2An O-ZnO catalyst.
Preferably, flower-like Cu2Dispersing O in the solution by ultrasonic, sequentially adding a zinc acetate alcohol solution and a lithium hydroxide alcohol solution, heating in a water bath for reaction, cooling to room temperature, taking out, alternately centrifuging and cleaning by using deionized water and ethanol, and drying in vacuum at 60 ℃ for 6 hours to obtain the low-dimensional self-assembled flower-shaped Cu2An O-ZnO catalyst.
Preferably, the mass percent of the ZnO quantum dots is 1-15wt%, the water bath temperature is 60-80 ℃, and the time is 15-20 min.
Preferably, the concentration of the zinc acetate is 12mg/ml, the concentration of the lithium hydroxide is 5mg/ml, and the volume ratio of the zinc acetate to the lithium hydroxide is 1: 1, the solution is ethanol or methanol.
Preferably, the flower-like Cu2The preparation process of O comprises the steps of dissolving copper nitrate, glutamic acid, glycine, sodium dihydrogen phosphate dihydrate and NaOH in deionized water, stirring to fully dissolve the copper nitrate, the glutamic acid, the glycine, the sodium dihydrogen phosphate dihydrate and the NaOH, then putting the mixture into a reaction kettle, carrying out hydrothermal reaction, cooling to room temperature, taking out the mixture, carrying out alternate centrifugal cleaning by the deionized water and ethanol, and carrying out vacuum drying at 60 ℃.
Preferably, the mass ratio of copper nitrate, glutamic acid, glycine, sodium dihydrogen phosphate dihydrate and NaOH is 4.2: 6: 6: 5: 19, the volume of the deionized water is 100-200 ml.
Preferably, the stirring speed is 100-200rpm, the stirring time is 10-30min, the hydrothermal reaction temperature is 140-160 ℃, and the reaction time is 2-4 h.
Preferably, after flower-shaped ZnO is ultrasonically dispersed in the solution, lithium hydroxide, copper chloride and ascorbic acid are sequentially added, magnetic stirring reaction is carried out for 30min at the temperature of 15-20 ℃ and the speed of 100-200rpm, the mixture is cooled to room temperature, and then the mixture is taken out, centrifugally cleaned by deionized water and ethanol alternately, and dried for 6h at the temperature of 60 ℃ in vacuum, thus obtaining the low-dimensional self-assemblyFilling flower shaped Cu2An O-ZnO catalyst.
Preferably, Cu2The mass percentage of the O quantum dots is 1-20wt%, and the concentrations of the lithium hydroxide, the copper chloride and the ascorbic acid are 0.1mol/l, 0.05mol/l and 0.025mol/l respectively.
Preferably, the flower-like ZnO is prepared by sequentially adding a zinc acetate solution and a sodium hydroxide solution into a citric acid solution, adding 20ml of ethanol, stirring for reaction, transferring the mixed solution into a reaction kettle for hydrothermal reaction, cooling to room temperature, taking out, centrifuging with deionized water and ethanol, and vacuum-drying at 80 ℃.
Preferably, the concentration of citric acid is 0.05g/ml, the concentration of zinc acetate is 0.15-0.02g/ml, the concentration of NaOH is 0.014-0.05g/ml, and the volume ratio is 1: (2-3): 2, the hydrothermal reaction temperature is 160-.
The low-dimensional self-assembly flower-shaped Cu prepared by the method2Application of O-ZnO catalyst in photocatalytic degradation of environmental pollutants and CO2Reduction and solar hydrogen production.
Has the advantages that:
the technical scheme of the invention has the following beneficial effects:
(1) synthesis of flower-like Cu by hydrothermal method2O or flower-shaped ZnO, and then obtaining the low-dimensional self-assembled flower-shaped Cu by a wet chemical method2O-ZnO catalyst, improves the defect of single catalyst, namely reduces pure Cu2The O photo-generated electron-hole recombination widens the photoresponse range of pure ZnO, can realize the absorption of sunlight full-wave band light and improve the photoelectric conversion efficiency, and can inhibit the recombination of carriers and improve the photocatalytic efficiency in all directions.
(2) By using flower-like Cu2O as core, ZnO quantum dot as decoration or flower-shaped ZnO as core, and Cu2The O nano-particles are decoration, have high specific surface area from the appearance of assembling into a three-dimensional structure, are beneficial to obtaining sufficient diffusion paths and enhanced reaction sites, and thus the catalytic efficiency of the composite catalyst is greatly improved.
(3) The flower-shaped Cu prepared by the invention2The O-ZnO catalyst can absorb the full-wave band light of sunlight and improve the photoelectric conversion efficiency, has large specific surface area, can provide more active points, and has high-efficiency photocatalytic efficiency, so that the obtained catalyst can degrade environmental pollutants and CO in photocatalysis2Has good application prospect in the fields of reduction, solar hydrogen production and the like.
(4) The invention synthesizes flower-shaped Cu by a hydrothermal method2O or flower-shaped ZnO, and then a wet chemical method is utilized to obtain the low-dimensional self-assembled flower-shaped Cu2The O-ZnO catalyst has simple preparation method and good repeatability, can be produced in large scale, and in addition, the obtained flower-shaped Cu2The O-ZnO catalyst has good chemical stability and is easy to store.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
In this embodiment, flower-like Cu is synthesized by hydrothermal method2O or flower-shaped ZnO, then using wet chemical method, centrifugal cleaning with deionized water and alcohol alternatively, drying to obtain low-dimensional self-assembly flower-shaped Cu2An O-ZnO catalyst. The specific scheme is as follows:
low-dimensional self-assembly flower-shaped Cu2Preparation method of O-ZnO catalyst, flower-like Cu2Ultrasonically dispersing O or flower-shaped ZnO in the solution, sequentially adding zinc acetate alcohol solution and lithium hydroxide alcohol solution or sequentially adding lithium hydroxide, copper chloride and ascorbic acid, reacting, cooling to room temperature, taking out, centrifugally cleaning and drying to obtain the low-dimensional self-assembled flower-shaped Cu2An O-ZnO catalyst.
As a preferred embodiment, flower-shaped Cu is used2Dispersing O in the solution by ultrasonic, sequentially adding a zinc acetate alcohol solution and a lithium hydroxide alcohol solution, heating in a water bath for reaction, cooling to room temperature, taking out, alternately centrifuging and cleaning by using deionized water and ethanol, and drying in vacuum at 60 ℃ for 6 hours to obtain the low-dimensional self-assembled flower-shaped Cu2An O-ZnO catalyst.
As a preferred embodiment, the mass percent of the ZnO quantum dots is 1-15wt%, the water bath temperature is 60-80 ℃, and the time is 15-20 min.
In a preferred embodiment, the concentration of zinc acetate is 12mg/ml, the concentration of lithium hydroxide is 5mg/ml, and the volume ratio of the two is 1: 1, the solution is ethanol or methanol.
As a preferred embodiment, the flower-like Cu2O is prepared by mixing sodium sulfateDissolving copper acid, glutamic acid, glycine, sodium dihydrogen phosphate dihydrate and NaOH in deionized water, stirring to fully dissolve the copper acid, the glutamic acid, the glycine, the sodium dihydrogen phosphate dihydrate and the NaOH, then putting the mixture into a reaction kettle, carrying out hydrothermal reaction, cooling to room temperature, taking out the mixture, carrying out alternate centrifugal cleaning by the deionized water and ethanol, and carrying out vacuum drying at 60 ℃.
As a preferred embodiment, the mass ratio of copper nitrate, glutamic acid, glycine, sodium dihydrogen phosphate dihydrate and NaOH is 4.2: 6: 6: 5: 19, the volume of the deionized water is 100-200 ml.
As a preferred embodiment, the stirring speed is 100-200rpm, the stirring time is 10-30min, the hydrothermal reaction temperature is 140-160 ℃, and the reaction time is 2-4 h.
As a preferred embodiment, after flower-shaped ZnO is ultrasonically dispersed in the solution, lithium hydroxide, copper chloride and ascorbic acid are sequentially added, magnetic stirring reaction is carried out at the temperature of 15-20 ℃ and the speed of 100-200rpm for 30min, cooling is carried out to room temperature, the flower-shaped ZnO is taken out, alternately centrifugally cleaned by deionized water and ethanol, and vacuum drying is carried out at the temperature of 60 ℃ for 6h, thus obtaining the low-dimensional self-assembled flower-shaped Cu2An O-ZnO catalyst.
As a preferred embodiment, Cu2The mass percentage of the O quantum dots is 1-20wt%, and the concentrations of the lithium hydroxide, the copper chloride and the ascorbic acid are 0.1mol/l, 0.05mol/l and 0.025mol/l respectively.
In a preferred embodiment, the flower-like ZnO is prepared by sequentially adding a zinc acetate solution and a sodium hydroxide solution to a citric acid solution, adding 20ml of ethanol, stirring for reaction, transferring the mixed solution to a reaction kettle for hydrothermal reaction, cooling to room temperature, taking out, centrifuging with deionized water and ethanol, and vacuum drying at 80 ℃.
In a preferred embodiment, the citric acid concentration is 0.05g/ml, the zinc acetate concentration is 0.15-0.02g/ml, the NaOH concentration is 0.014-0.05g/ml, and the volume ratio is 1: (2-3): 2, the hydrothermal reaction temperature is 160-.
The low-dimensional self-assembly flower-shaped Cu prepared by the method2Application of O-ZnO catalyst in photocatalytic degradation of environmental pollutants and CO2Reduction and solar hydrogen production.
The flower-shaped Cu obtained by the technical scheme of the embodiment is obtained by the following groups of examples and comparative examples2The beneficial effects of the O-ZnO catalyst are further illustrated.
The first embodiment is as follows:
the embodiment is in the form of flower Cu2The synthesis method of the heterogeneous composite catalyst with O as a core and ZnO quantum dots for decoration comprises the following steps of:
step 1: flower-shaped Cu with self-assembled nanosheets2Preparation of O: dissolving 0.83g of copper nitrate trihydrate, 1.2g of glutamic acid, 1.2g of glycine, 1.0g of sodium dihydrogen phosphate dihydrate and 3.8g of NaOH in 150ml of deionized water, stirring at the rotating speed of 150rpm for 20min to dissolve the copper nitrate trihydrate, transferring the mixture into a reaction kettle to react at 160 ℃ for 2 hours, cooling to room temperature, taking out the mixture, cleaning the mixture with deionized water and ethanol, and drying the mixture in vacuum at 60 ℃ to obtain the flower-shaped Cu with the self-assembled nanosheets2O (as shown in fig. 1 and 2).
Step 2: taking the synthesized flower-shaped Cu2Dispersing O40 mg in 20ml ethanol by ultrasonic, sequentially adding 270ul of 0.012g/ml zinc acetate ethanol solution and 270ul of 0.005g/ml lithium hydroxide ethanol solution, reacting at the water bath temperature of 60 ℃ and 150rpm for 15min, cooling to room temperature, centrifugally cleaning by ethanol, and drying in vacuum at 60 ℃ for 6h to obtain the nanosheet self-assembled flower-shaped Cu2An O-ZnO catalyst.
Example two:
the embodiment is in the form of flower Cu2The synthesis method of the heterogeneous composite catalyst with O as a core and ZnO quantum dots for decoration comprises the following steps of:
step 1: flower-shaped Cu with self-assembled nanosheets2Preparation of O: dissolving 0.83g of copper nitrate trihydrate, 1.2g of glutamic acid, 1.2g of glycine, 1.0g of sodium dihydrogen phosphate dihydrate and 3.8g of NaOH in 150ml of deionized water, stirring at the rotating speed of 150rpm for 20min to dissolve the copper nitrate trihydrate, transferring the mixture into a reaction kettle to react at the temperature of 140 ℃ for 4 hours, cooling to room temperature, taking out the mixture, cleaning the mixture by using the deionized water and ethanol, and drying the mixture in vacuum at the temperature of 60 ℃ to obtain the flower-shaped Cu with the self-assembled nanosheets2O。
Step 2: taking the synthesized flower-shaped Cu2Dispersing O40 mg in 20ml ethanol by ultrasonic, then adding 450ul of 0.012g/ml zinc acetate ethanol solution and 450ul of 0.005g/ml lithium hydroxide ethanol solution in sequence, reacting for 15min at the water bath temperature of 60 ℃ at 150rpm, then cooling to room temperature, centrifugally cleaning by ethanol, and drying in vacuum for 6h at 60 ℃ to obtain the nanosheet self-assembled flower-shaped Cu2An O-ZnO catalyst.
Example three:
the embodiment is in the form of flower Cu2The synthesis method of the ZnO quantum dot decorated heterogeneous composite catalyst with O as a core comprises the following steps:
step 1: flower-shaped Cu with self-assembled nanosheets2Preparation of O: dissolving 0.83g of copper nitrate trihydrate, 1.2g of glutamic acid, 1.2g of glycine, 1.0g of sodium dihydrogen phosphate dihydrate and 3.8g of NaOH in 150ml of deionized water, stirring at the rotating speed of 150rpm for 20min to dissolve the copper nitrate trihydrate, transferring the mixture into a reaction kettle to react at the temperature of 140 ℃ for 4 hours, cooling to room temperature, taking out the mixture, cleaning the mixture by using the deionized water and ethanol, and drying the mixture in vacuum at the temperature of 60 ℃ to obtain the flower-shaped Cu with the self-assembled nanosheets2O。
Step 2: taking the synthesized flower-shaped Cu2Dispersing O40 mg in 20ml ethanol by ultrasonic, then sequentially adding 1.5ml of 0.012g/ml zinc acetate ethanol solution and 1.5ml of 0.005g/ml lithium hydroxide ethanol solution, reacting for 15min at the water bath temperature of 60 ℃ at 150rpm, then cooling to room temperature, centrifugally cleaning by ethanol, and drying in vacuum at 60 ℃ for 6h to obtain the nanosheet self-assembled flower-shaped Cu2An O-ZnO catalyst.
Example four:
in this example, Cu is grown with flower-like ZnO as a nucleus2Method for the synthesis of O nanoparticle decorated heterogeneous composite catalysts, in which Cu2The mass percent of the O quantum dots is 1wt%, and the method comprises the following steps:
step 1: dissolving 0.5g of citric acid in 10ml of deionized water, dissolving 0.58g of zinc acetate in 30ml of deionized water, dissolving 1.04g of NaOH in 20ml of water, then slowly and sequentially dripping the zinc acetate solution and the sodium hydroxide solution into the citric acid solution, then dripping 10ml of ethanol, reacting for 30min, transferring the solution into a reaction kettle, preserving heat at 180 ℃ for 6h, cooling to room temperature, taking out, centrifuging, and drying at 80 ℃ to obtain the nano-sheet self-assembled flower-shaped ZnO.
Step 2: 40mg of the flower-shaped ZnO prepared above is dissolved in 20ml of deionized water, after ultrasonic dispersion is carried out for 1h, 0.6ml of 0.1mol/l lithium hydroxide and 0.6ml of 0.05mol/l CuCl are sequentially added2And 0.6ml of 0.025mol/l ascorbic acid, magnetically stirring the mixture at 20 ℃ and 150rpm for reaction for 30 minutes, centrifuging the reaction product, and drying the reaction product in vacuum at 60 ℃ to obtain the nanosheet self-assembled flower-shaped Cu2An O-ZnO catalyst.
Example five:
in this example, Cu is grown with flower-like ZnO as a nucleus2Method for the synthesis of O nanoparticle decorated heterogeneous composite catalysts, in which Cu2The mass percent of the O quantum dots is 3wt%, and the method comprises the following steps:
step 1: dissolving 0.5g of citric acid in 10ml of deionized water, dissolving 0.58g of zinc acetate in 30ml of deionized water, dissolving 1.04g of NaOH in 20ml of deionized water, then slowly dripping the zinc acetate solution and the sodium hydroxide solution into the citric acid solution in sequence, then dripping 10ml of ethanol, reacting for 30min, transferring the solution into a reaction kettle, preserving the temperature for 8h at 160 ℃, cooling to room temperature, taking out, centrifuging, and drying at 80 ℃ to obtain the nano-sheet self-assembled flower-shaped ZnO (shown in figure 3).
Step 2: 40mg of the flower-shaped ZnO prepared above is dissolved in 20ml of deionized water, after 1 hour of ultrasonic dispersion, 1.7ml of 0.1mol/l lithium hydroxide and 1.7ml of 0.05mol/l CuCl are added in turn2And 1.7ml of 0.025mol/l ascorbic acid, magnetically stirring the mixture at 20 ℃ and 150rpm for reaction for 30 minutes, centrifuging the reaction product, and drying the reaction product in vacuum at 60 ℃ to obtain the nanosheet self-assembled flower-shaped Cu2An O-ZnO catalyst.
Example six:
in this example, Cu is grown with flower-like ZnO as a nucleus2Method for the synthesis of O nanoparticle decorated heterogeneous composite catalysts, in which Cu2The mass percent of the O quantum dots is 5wt%, and the method comprises the following steps:
step 1: dissolving 0.5g of citric acid in 10ml of deionized water, dissolving 0.58g of zinc acetate in 30ml of deionized water, dissolving 1.04g of NaOH in 20ml of water, then slowly and sequentially dripping the zinc acetate solution and the sodium hydroxide solution into the citric acid solution, then dripping 10ml of ethanol, reacting for 30min, transferring the solution into a reaction kettle, preserving heat at 180 ℃ for 6h, cooling to room temperature, taking out, centrifuging, and drying at 80 ℃ to obtain the nano-sheet self-assembled flower-shaped ZnO.
Step 2: dissolving 20mg of the flower-shaped ZnO prepared in the above into 20ml of deionized water, ultrasonically dispersing for 1h, and then sequentially adding 0.8ml of 0.1mol/l lithium hydroxide and 0.8ml of 0.05mol/l CuCl2And 0.8ml of 0.025mol/l ascorbic acid, magnetically stirring and reacting for 30 minutes at 20 ℃ and 150rpm, centrifuging, and drying in vacuum at 60 ℃ to obtain the nanosheet self-assembled flower-shaped Cu2An O-ZnO catalyst.
Example seven:
in this example, Cu is grown with flower-like ZnO as a nucleus2Method for the synthesis of O nanoparticle decorated heterogeneous composite catalysts, in which Cu2The mass percent of the O quantum dots is 20wt%, and the method comprises the following steps:
step 1: dissolving 0.5g of citric acid in 10ml of deionized water, dissolving 0.029g of zinc acetate in 20ml of ethanol, dissolving 0.27g of NaOH in 20ml of water, then slowly dripping the zinc acetate solution and the sodium hydroxide solution into the citric acid solution in sequence, reacting for 30min, transferring the solution into a reaction kettle, preserving the temperature at 180 ℃ for 6h, cooling to room temperature, taking out, centrifuging, and drying at 80 ℃ to obtain the nanorod self-assembled flower-shaped ZnO (shown in figure 4).
Step 2: dissolving 20mg of the flower-shaped ZnO prepared in the above into 20ml of deionized water, ultrasonically dispersing for 1h, and then sequentially adding 6ml of 0.1mol/l lithium hydroxide and 6ml of 0.05mol/l CuCl2And 6ml of 0.025mol/l ascorbic acid, magnetically stirring the mixture at 20 ℃ and 150rpm for reaction for 30 minutes, centrifuging the reaction product, and drying the reaction product in vacuum at 60 ℃ to obtain the nanorod self-assembled flower-shaped Cu2An O-ZnO catalyst (as shown in figure 5).
FIGS. 1 and 2 show Cu prepared in example one2O low power scanning electron microscope photo and high power scanning electron microscope photo, showing that the Cu is prepared2The shape of O is the flower shape of a nano sheet, the size is uniform, and the dispersity is good; FIG. 3 is a scanning electron microscope photograph of ZnO prepared in example V, which shows that the prepared ZnO is in the form of a nanosheet and has good dispersibility; FIGS. 4 and 5 show ZnO and Cu, respectively, prepared in EXAMPLE VII2Scanning electron microscope photographs of the O-ZnO catalyst show that the prepared ZnO and Cu2The shapes of the O-ZnO catalysts are all flower shapes of nanorods.
The invention synthesizes flower-shaped Cu by a hydrothermal method2O or flower-shaped ZnO, and then obtaining the low-dimensional self-assembled flower-shaped Cu by a wet chemical method2O-ZnO catalyst, improves the defect of single catalyst, namely reduces pure Cu2The O photo-generated electrons and holes are compounded, the photoresponse range of pure ZnO is widened, the full-wave-band light of sunlight can be absorbed, the photoelectric conversion efficiency of the pure ZnO photo-generated electrons and holes can be improved, the compounding of carriers can be inhibited, and the photocatalytic efficiency is improved in all directions; furthermore, by using flower-like Cu2O as core, ZnO quantum dot as decoration or flower-shaped ZnO as core, and Cu2The O nano-particles are decoration, have high specific surface area from the appearance of assembling into a three-dimensional structure, are beneficial to obtaining sufficient diffusion paths and enhanced reaction sites, and thus the catalytic efficiency of the composite catalyst is greatly improved. The flower-shaped Cu prepared by the invention2The O-ZnO catalyst can absorb the full-wave band light of sunlight and improve the photoelectric conversion efficiency, has large specific surface area, can provide more active points, and has high-efficiency photocatalytic efficiency, so that the obtained catalyst can degrade environmental pollutants and CO in photocatalysis2Has good application prospect in the fields of reduction, solar hydrogen production and the like. Finally, the invention synthesizes flower-shaped Cu by a hydrothermal method2O or flower-shaped ZnO, and then a wet chemical method is utilized to obtain the low-dimensional self-assembled flower-shaped Cu2The O-ZnO catalyst has simple preparation method and good repeatability, can be produced in large scale, and the obtained flower-shaped Cu2The O-ZnO catalyst has good chemical stability and is easy to store.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.