One method for preparing zinc oxide hollow spheres
Technical field
The present invention relates to the zinc oxide nano-particle field, be specifically related to a method for preparing zinc oxide hollow spheres.
Background technology
The preparation method of Zinc oxide hollow spheres mainly contains hydrothermal method, template agent method (hard mould agent or soft template), high temperature vapour deposition process etc., but its synthetic time-consuming and power consumption, and for the applied research of hollow ball also seldom.
Sonochemistry is widely used for preparing the nano material of various patterns as a kind of high efficient and convenient synthetic method." acoustic cavitation " effect that ultrasound wave irradiation produces, in the extremely short time, in the little space around the cavitation bubble, to produce high temperature 5000K and the high pressure (20MPa) of moment and surpass the speed of cooling of 1010K/S. and the shockwave of accompanied by intense, jet and photoelectric action, the high-temperature and high-pressure conditions that this moment produces has represented the incomparable advantage of additive method in novel material is synthetic. as effective control pattern, accelerate speed of reaction, productive rate height, easy to operate and clean environment firendly etc.If the sonochemistry method can be used to prepare Zinc oxide hollow spheres, might make the performance of Zinc oxide hollow spheres of gained better, and the preparation method is also simple before.
Summary of the invention
The objective of the invention is to synthetic loaded down with trivial detailsly according to what exist in the existing method that prepare Zinc oxide hollow spheres, the big shortcoming that consumes energy provides a kind of simple and convenient quick and can improve the preparation method of Zinc oxide hollow spheres performance.
The object of the invention is achieved by the following technical programs:
One method for preparing zinc oxide hollow spheres comprises the steps: that (1) is dissolved in zinc salt in the mixed solvent of organic solvent and water, carries out ultrasonic reaction; (2) with the product centrifugation, process washing, alcohol are washed, drying, obtain Zinc oxide hollow spheres.
Utilize ultrasonic method of the present invention to prepare by zinc oxide nano-particle (10~50nm) Zinc oxide hollow spheres of forming (100~1000nm).
As a kind of preferred version, among the above-mentioned preparation method, described zinc salt is zinc acetate, zinc nitrate, zinc chloride or zinc sulfate, and the volumetric molar concentration of zinc salt is 0.005~0.5mol/L.
As a kind of preferred version, among the above-mentioned preparation method, described organic solvent is dimethyl sulfoxide (DMSO), N, dinethylformamide, glycol ether, ethylene glycol or glycerol; Wherein, the volume of water accounts for 5~95 volume % of mixed solvent volume.
As a kind of preferred version, among the above-mentioned preparation method, described ultrasonic reaction is finished by ultrasonic apparatus, and the power of ultrasonic apparatus is 50~500W, and amplitude is 10~90%.
As a kind of preferred version, among the above-mentioned preparation method, the time of described ultrasonic reaction is 1~180min.
As a kind of preferred version, among the above-mentioned preparation method, described exsiccant temperature is 20~100 ℃.
The Zinc oxide hollow spheres that the inventive method makes utilizes X-ray powder diffraction, scanning electron microscope, transmission electron microscope to carry out detailed sign.
The growth mechanism of described Zinc oxide hollow spheres is first through overbunching, is promptly assembled forming solid sphere by the zinc oxide nano-particle assembling, and then through the oersted maturing process, finally forms hollow ball structure.
The Zinc oxide hollow spheres that the inventive method makes can be widely used in fields such as catalysis, chemical reaction carrier, drug delivery, makeup, coating, solar cell.When especially being used for field of dye-sensitized solar cells, has higher photoelectric transformation efficiency than conventional zinc oxide nano-particle as the light anode.
Compared with prior art, the present invention has following beneficial effect:
(1) the present invention utilizes ultrasonic method to prepare the classification Zinc oxide hollow spheres, and the ultrasonic method of classification Zinc oxide hollow spheres has synthetic method and reaches high repeatability and other advantages simply, easily and fast;
(2) utilize institute's synthetic Zinc oxide hollow spheres to obtain the photoelectric transformation efficiency higher than conventional zinc oxide nano-particle, higher by 38.8% than traditional nanoparticle;
(3) Zinc oxide hollow spheres of preparation method's gained of the present invention can be used to prepare dye-sensitized solar cells; this battery mainly is an imitation photosynthesis principle; a kind of novel solar cell of developing; its main advantage is: abundant raw materials, cost is low, Technology is simple relatively; in the big area suitability for industrialized production, has bigger advantage; all raw material and production technique all are nontoxic, free of contamination simultaneously; the part material can be reclaimed fully, and the protection human environment is had great importance.
Description of drawings
Fig. 1 is the XRD figure of the Zinc oxide hollow spheres after the differential responses time; (a) 3min, (b) 10min, (c) 30min, (d) 1h;
Fig. 2 is the SEM of the Zinc oxide hollow spheres behind the ultrasonic reaction 30min, TEM figure; (a) scanning electron microscope (SEM) figure, (b) low power transmission electron microscope (TEM) figure, (c) TEM of single Zinc oxide hollow spheres figure, (d) high-resolution-ration transmission electric-lens (HRTEM) figure;
Fig. 3 is the sem photograph of different ultrasonic reaction time synthetic Zinc oxide hollow spheres; (a)~(b) 3min, (c)-(d) 10min, (e)~(f) 1h;
Fig. 4 is the relation of dye sensitization solar battery photoelectric transformation efficiency and Zinc oxide hollow spheres thickness.
Embodiment
Further explain the present invention below in conjunction with embodiment, but embodiment does not do any type of qualification to the present invention.
Embodiment
Utilize zinc acetate, dimethyl sulfoxide (DMSO), water as raw material, utilize ultrasound wave irradiation to synthesize the classification Zinc oxide hollow spheres.Claim the 1.098g zinc acetate to put into the beaker of a 100ml, add the 47.5ml dimethyl sulfoxide (DMSO), add 2.5ml water again, the probe of ultrasonic cell disruption instrument is put into beaker, and be 300W with its power regulation, it is 8s that ultrasound mode is set, the time is 1h, ultrasonic end back centrifugation extracting waste precipitation, washing, alcohol are washed each 3 times again.Get final product 60 ℃ of oven dry.
Dried white powder is directly used in the XRD test, judge its crystal formation, found that prepared zinc oxide is the wurtzite structure (see figure 1), observe its pattern with scanning electron microscope, measure its pattern and crystalline structure (Fig. 2) with transmission electron microscope, the classification Zinc oxide hollow spheres of finding submicron-scale is molecular by nanoparticle, and wherein nano-particles size is about 15 nanometers, and hollow ball is of a size of 500 nanometers.Observe the pattern (Fig. 3) of the sample of differential responses time by scanning electron microscope, and the growth mechanism of hollow ball is discussed, find that Zinc oxide hollow spheres forms through overbunching and oersted maturing process.
Ethyl cellulose, Terpineol 350 and ethanol are joined in the Zinc oxide hollow spheres, grind 30min and form slurry.
Utilize silk screen print method that zinc oxide slurry is coated in through on the conductive glass that cleans, then 500 ℃ of calcination, the thickness of zinc oxide can be regulated and control by printing different number of times.
Being coated in Zinc oxide film on the conductive glass through calcining is placed in the N719 dyestuff of 0.5mM and soaks 15~24h, conductive glass (counter electrode) with deposition Pt fits together then, and the adding ionogen (prescription of electrolytic solution: 0.6mol/L PMII, 0.03mol/L I
2, it is in 85: 15 the acetonitrile and valeronitrile mixed solution that 0.05mol/L LiI, 0.1mol/L Guanidiniumthiocyanate (GuSCN), 0.5mol/L 4-tert-butylpyridine (TBP) are dissolved in volume ratio), promptly can be used to the testing photoelectronic efficiency of conversion.The photoelectric transformation efficiency of gained and the thickness of Zinc oxide hollow spheres have the (see figure 4) of relation, the highest photoelectric transformation efficiency is 4.33%, it is based on the Zinc oxide hollow spheres of 9.1 micron thickness, than with the photoelectric transformation efficiency (3.12%) of the zinc oxide nano-particle of 9.0 micron thickness high about 38.8%.