A kind of perovskite-based composite nano materials and preparation method and purposes
Technical field
The present invention relates to a kind of perovskite-based composite nano materials and preparation methods and purposes, belong to material preparation and light is urged
The technical field of change.
Technical background
In recent years, photocatalysis technology is because with low energy consumption, reaction condition is mild and the various features such as non-secondary pollution, by
To the extensive concern of researcher.Photocatalysis technology can convert the solar energy of low-density to highdensity chemical energy (Hydrogen Energy),
Can degrade again and the organic pollution in mineralising environment and antibiotic, therefore it is in solution energy crisis and problem of environmental pollution
There is important application value.
In numerous two-dimensional semiconductor materials, from Dion-Jacobson phases (M [An-1BnO3n+1]) laminated perovskite structure niobium
The two-dimentional calcium niobate potassium (K that hydrochlorate separates+Ca2Nb3O10 -) poly metal oxide nano piece energy with good stability, especially
It is that the conduction band of the nanosheet photocatalytic material is made of the Nb 4d tracks of high level, and the light induced electron of generation is with very strong
Reducing power.But simple two-dimentional K+Ca2Nb3O10 -Catalysis material lacks enough active sites, causes its surface a large amount of
Light induced electron is quenched with hole recombination, to reduce photocatalysis efficiency.In order to solve this problem, simple K+Ca2Nb3O10 -
It is often used to, with the composite photocatalyst material of the compound preparation binary of the progress such as oxide or sulfide, ternary, especially build
Heterojunction material;The heterojunction material of this special designing can be effectively promoted the separation in light induced electron and hole, inhibit photoproduction
Electronics and hole it is compound, finally improve photocatalysis efficiency.
In numerous photocatalytic semiconductor materials, bismuth oxychloride (BiOCl) is connected to two Cl because having-[Bi2O2
]2+Two-dimensional layered structure, and show excellent physicochemical property.(001) crystal face of BiOCl possesses higher end oxygen atom density
And Lacking oxygen is formed, improve its photocatalytic activity.Because possessing the band structure to match, BiOCl is urged with laminated perovskite type light
Change material K+Ca2Nb3O10 -It is compound to form II type hetero-junctions, possess the separative efficiency in higher light induced electron and hole, in turn
Improve photocatalytic activity.Meanwhile compared to zero dimension/two dimension, one-dimensional/two dimensional heterostructures, two-dimentional BiOCl/ two dimensions K+
Ca2Nb3O10 -The formation of hetero-junctions possesses more active sites, improves light capture ability.
So far, it is not yet found that people prepares BiOCl/K using hydro-thermal method+Ca2Nb3O10 -Hetero-junctions composite Nano material
Material, K used+Ca2Nb3O10 -With stable physicochemical property, raw material are cheap and easy to get, nontoxic, and are prepared using it as carrier
BiOCl/K+Ca2Nb3O10 -The reaction process of hetero-junctions composite nano materials is simple, and products obtained therefrom photocatalytic activity is good, stability
Height, production process is environmentally protective, is expected to large-scale industrial production.
Invention content
It is an object of the present invention to provide it is a kind of it is new under cryogenic, with simple and practicable hydro-thermal method fabricated in situ Z-type
BiOCl/K+Ca2Nb3O10 -The method of hetero-junctions composite nano materials.
The present invention is realized by following steps:
(1) calcium niobate potassium nanometer sheet (K is prepared+Ca2Nb3O10 -):Weigh the K of a certain amount of drying2CO3、CaCO3And Nb2O5In
In mortar, it is placed in semi-enclosed crucible through being fully ground mixing, crucible is then transferred to the heating of auto-programming temperature control
It is calcined in tube furnace.It after room temperature, takes out, with mortar grinder to after powdered, is added to 5molL-1HNO3
A couple of days is stirred in solution, carries out protonation processing.The white precipitate deionized water and washes of absolute alcohol that protonation is obtained
Remove HNO3, then centrifuge, it is dried to obtain white solid HCa2Nb3O10.Weigh a certain amount of HCa2Nb3O10A certain amount of quality is added
After tetrabutylammonium hydroxide solution and appropriate amount of deionized water stirring a couple of days of score 10%, through centrifuging to obtain upper layer colloidal substance.
Colloidal substance is finally added dropwise to 2molL-1Obtain white precipitate in KCl solution, by above-mentioned precipitation deionized water and
Washes of absolute alcohol, centrifugation are dried in vacuo (ChemSusChem, 2016,9,396-402).
(2) bismuth oxychloride/calcium niobate potassium hetero-junctions composite nano materials (BiOCl/K is prepared+Ca2Nb3O10 -):It weighs certain
The K of amount+Ca2Nb3O10 -It is scattered in deionized water, the suspension of stable homogeneous is obtained through ultrasound, stir process.In the feelings of stirring
Under condition, a certain amount of Bi (NO are added3)3·5H2O and KCl is sufficiently mixed in above-mentioned suspension.Reaction solution, which is transferred to liner, is
In the reaction kettle of polytetrafluoroethylene (PTFE), it is placed in hydro-thermal reaction in baking oven, obtained product deionized water and absolute ethyl alcohol is cleaned, from
The heart, vacuum drying obtain bismuth oxychloride/calcium niobate potassium hetero-junctions composite nano materials.
In the calcium niobate potassium nanometer sheet building-up process, K+、Ca2+And Nb5+Molar ratio be 1.1:2:3.HCa2Nb3O10With
The ratio of tetrabutylammonium hydroxide is 1g:5ml.
In the bismuth oxychloride/calcium niobate potassium hetero-junctions composite nano materials, bismuth oxychloride accounts for bismuth oxychloride/calcium niobate potassium
The 10%-50% of hetero-junctions composite nano materials gross mass, preferably 40%.
The power of ultrasonic machine used in the ultrasonic disperse is 250W, sonication treatment time 0.5-1h.
It is 1-1.5h that the stir process, which uses magnetic stirring apparatus, stir process time,.
The temperature of the hydro-thermal reaction is 150-200 DEG C, reaction time 18-24h.
Utilize X-ray diffractometer (XRD), transmission electron microscope (TEM) and high resolution transmission electron microscopy
(HRTEM) micromorphology analysis is carried out to product, is that target dyestuff carries out photocatalysis with quadracycline (TC, 35mg/L) solution
Degradation experiment measures absorbance, to assess its Photocatalytic Degradation Property by ultraviolet-visible spectrophotometer.
Description of the drawings
Fig. 1 is K+Ca2Nb3O10 -, BiOCl and BiOCl/K+Ca2Nb3O10 -The XRD diffraction of hetero-junctions nano-photocatalyst
Spectrogram, as can be seen from the figure BiOCl/K+Ca2Nb3O10 -XRD spectrum mainly by BiOCl and K+Ca2Nb3O10 -Diffraction maximum structure
At.
Fig. 2A, B, C are respectively simple K+Ca2Nb3O10 -Sample, simple BiOCl samples, BiOCl/K+Ca2Nb3O10 -Hetero-junctions
The transmission electron microscope photo of composite nano materials;D is BiOCl/K+Ca2Nb3O10 -The high-resolution of hetero-junctions composite nano materials transmits
Electromicroscopic photograph.As seen from the figure, BiOCl nanometer sheets are successfully compounded in K+Ca2Nb3O10 -Nanometer sheet surface.
Fig. 3 be different quality than catalysis material degrade the when m- degradation rate relational graph of TC solution, prepared 40%
BiOCl/K+Ca2Nb3O10 -There is hetero-junctions composite nano materials most excellent photocatalytic activity, sample to react 150min in catalysis
TC solution degradations rate has reached 94.5% afterwards.
Specific implementation mode
1 calcium niobate potassium nanometer sheet (K of embodiment+Ca2Nb3O10 -) prepare
The preparation of calcium niobate potassium nanometer sheet uses high-temperature solid phase reaction method:Weigh 0.3406g K2CO3、0.8968g CaCO3
With 1.7865g Nb2O5It in mortar, is placed in semi-enclosed crucible through being fully ground mixing, is then transferred to crucible certainly
1200 DEG C of calcining 10h in the heating tube furnace of dynamic program temperature control.After naturally cool to being taken out after room temperature, with mortar grinder to powder
After shape, 4g is taken to be added to 200ml 5molL-1HNO33d is stirred in solution, carries out protonation processing.Protonation is obtained white
Color precipitation uses 3 removing HNO of deionized water and washes of absolute alcohol respectively3, then centrifuge through 6000rad/min, 60 DEG C of drying 12h
Obtain white solid HCa2Nb3O10.Take 0.1g HCa2Nb3O10With the tetrabutylammonium hydroxide solution of 0.5ml mass fractions 10%
It is scattered in 100ml deionized waters stirring 7d, upper layer colloid object is centrifuged to obtain through 1500rad/min.Dropwise by colloid object finally
It is added to 100ml 2molL-1White precipitate is obtained in KCl solution, above-mentioned precipitation is used into deionized water and absolute ethyl alcohol respectively
Cleaning 3 times, centrifuges through 6000rad/min, is finally placed in 60 DEG C of vacuum drying chambers and dries for 24 hours.
2 40%BiOCl/K of embodiment+Ca2Nb3O10 -The preparation of hetero-junctions composite nano materials
BiOCl/K+Ca2Nb3O10 -The preparation of hetero-junctions composite nano materials uses traditional hydro-thermal method:Weigh 0.0391g
K+Ca2Nb3O10 -It is scattered in 65ml deionized waters, sonicated 1h and stir process 1.5h obtain the suspended of stable homogeneous
Liquid.In the case of stirring, 0.0485g Bi (NO are added3)3·5H2O and 0.0075g KCl are fully mixed in above-mentioned suspension
It closes.It is to be put into 160 DEG C of water in baking oven in the reaction kettle that polytetrafluoroethylene (PTFE) capacity is 100ml that above-mentioned reaction solution, which is transferred to liner,
For 24 hours, cooled to room temperature, obtained product uses deionized water and washes of absolute alcohol 3 times to thermal response respectively, through 4500rad/
Min is centrifuged, and is finally placed in 60 DEG C of vacuum drying chambers dry 12h and is obtained 40%BiOCl/K+Ca2Nb3O10 -Hetero-junctions composite Nano
Material.
Embodiment 3CdIn2S4/g-C3N4/ GO composite material photocatalytic activities are tested
(1) compound concentration is the TC solution of 35mg/L, and the solution prepared is kept in dark place.
(2) weigh different quality than BiOCl/K+Ca2Nb3O10 -Hetero-junctions composite nano materials 0.035g, is respectively placed in
In photo catalysis reactor, the target degradation solution that 35mL steps (1) are prepared is added, the lower magnetic agitation 60min of dark waits for BiOCl/
K+Ca2Nb3O10 -Hetero-junctions composite nano materials be uniformly dispersed and with TC reach absorption-desorption balance after, open cooling water and
300W xenon sources carry out photocatalytic degradation experiment.
(3) the photocatalytic degradation liquid in reactor is drawn per 30min, and the measurement of UV-visible absorbance is used for after centrifugation.
(4) prepared BiOCl/K as seen from Figure 3+Ca2Nb3O10 -There is hetero-junctions composite nano materials excellent light to urge
Change activity, especially 40%BiOCl/K+Ca2Nb3O10 -Sample catalysis react 150min after TC solution degradation rates have reached
94.5%.