阅读说明：本技术 一种Cr掺杂磷酸镍钠光催化材料及其制备方法 (Cr-doped sodium nickel phosphate photocatalytic material and preparation method thereof ) 是由 许开华 陈龙 苏陶贵 王超 张云河 许鹏云 于 2018-08-30 设计创作，主要内容包括：本发明公开了一种Cr掺杂磷酸镍钠光催化材料,其基底材料的化学式为Na<Sub>4</Sub>Ni<Sub>3</Sub>P<Sub>4</Sub>O<Sub>15</Sub>,所述基底材料的表面掺杂Cr离子；本发明还公开了该Cr离子掺杂磷酸镍钠光催化材料的制备方法。本发明通过选用水合碳镍钠+磷酸+铬盐来制备铬盐掺杂磷酸镍钠光催化材料的方法,有效的避免了其他杂质的引入,提高了合成磷酸镍钠的纯度,同时Cr引入提高了其光催化活性；通过在磷酸镍钠的表面掺杂Cr盐,有效的扩宽了磷酸镍钠在紫外光、可见光区域相应的范围,影响其结构形成晶格缺陷,有利于光生电子对分离；本发明方法为绿色反应,无需复杂工艺,控制简单,成本低廉,具有很大的工业化潜力。(The invention discloses a Cr-doped sodium nickel phosphate photocatalytic material, wherein the chemical formula of a substrate material of the material is Na 4 Ni 3 P 4 O 15 The surface of the substrate material is doped with Cr ions; the invention also discloses a preparation method of the Cr ion doped nickel sodium phosphate photocatalytic material. According to the method for preparing the chromium salt doped nickel sodium phosphate photocatalytic material by selecting the hydrated carbon nickel sodium, the phosphoric acid and the chromium salt, the introduction of other impurities is effectively avoided, the purity of the synthesized nickel sodium phosphate is improved, and the photocatalytic activity of the synthesized nickel sodium phosphate is improved by introducing the Cr; by doping Cr salt on the surface of the nickel sodium phosphate, the corresponding range of the nickel sodium phosphate in ultraviolet and visible light regions is effectively widened, the structure of the nickel sodium phosphate is influenced to form lattice defects, and the separation of photo-generated electron pairs is facilitated; the method is a green reaction, does not need a complex process, is simple to control, has low cost and has great industrialization potential.)

1. A Cr-doped sodium nickel phosphate photocatalytic material is characterized in that the chemical formula of a substrate material is Na₄Ni₃P₄O₁₅And the surface of the substrate material is doped with Cr salt.

2. A preparation method of a Cr-doped sodium nickel phosphate photocatalytic material is characterized by comprising the following steps:

step 1, adding sodium-containing basic nickel carbonate into a phosphoric acid solution for a dissolution reaction to obtain a sodium-containing nickel phosphate solution;

step 2, adding a chromium salt into the sodium-containing nickel phosphate solution obtained in the step 1, stirring for reaction, and then carrying out concentration crystallization to obtain a Cr-doped nickel sodium phosphate crystal mixture;

and 3, calcining the Cr-doped nickel sodium phosphate crystal mixture obtained in the step 2 at a low temperature, and cooling to obtain the Cr-doped nickel sodium phosphate photocatalytic material.

3. The method for preparing a Cr-doped nickel sodium phosphate photocatalytic material according to claim 2, wherein in the step 1, the molar ratio of the basic nickel carbonate containing sodium to the phosphoric acid in the phosphoric acid solution is (1.0-1.3): 1.

4. the method for preparing a Cr-doped nickel sodium phosphate photocatalytic material according to claim 3, wherein in the step 2, the molar ratio of the added amount of the chromium salt to the basic nickel carbonate containing sodium is (0.015-0.33): 1.

5. the method for preparing the Cr-doped sodium nickel phosphate photocatalytic material according to claim 4, wherein in the step 2, the chromium salt is at least one of chromium sulfate, chromium chloride and chromium nitrate.

6. The method for preparing the Cr-doped sodium nickel phosphate photocatalytic material according to claim 5, wherein in the step 2, the stirring reaction time is 3-5 hours.

7. The method for preparing the Cr-doped sodium nickel phosphate photocatalytic material as claimed in any one of claims 1 to 6, wherein in the step 3, the calcination temperature is 300-800 ℃, and the calcination time is 2-10 h.

8. The method for preparing a Cr-doped nickel sodium phosphate photocatalytic material according to claim 7, wherein in the step 1, the specific preparation method of the basic nickel carbonate containing sodium is as follows:

step 1.1, simultaneously adding a sodium carbonate solution with the concentration of 180-300 g/L and a nickel sulfate solution with the concentration of 60-100 g/L into a reactor, and obtaining basic nickel carbonate slurry after adjusting the pH value of a flow control system of the sodium carbonate solution and the nickel sulfate solution to be 8.2-8.3 and reacting for 20-25 h at 50-60 ℃ in the feeding process, wherein the flow of the sodium carbonate solution is 100-1000L/h, and the flow of the nickel sulfate solution is 100-1000L/h;

step 1.2, stopping adding the sodium carbonate solution and the nickel sulfate solution into the reactor, and controlling the crystal form transformation of the basic nickel carbonate in the basic nickel carbonate slurry obtained in the step 1.1 by adjusting the reaction temperature and the reaction time to obtain hydrated sodium nickel carbonate seed crystals;

step 1.3, adding the sodium carbonate solution and the nickel sulfate solution into the reactor again, wherein the pH value of a flow control system of the sodium carbonate solution and the nickel sulfate solution is adjusted to be 8.5-8.8 in the feeding process, and the growth of the hydrated nickel carbonate crystal seed obtained in the step 1.2 is controlled by adjusting the reaction temperature and the reaction time to obtain a crude sodium-containing basic nickel carbonate product;

step 1.4, sequentially aging the crude sodium-containing basic nickel carbonate product obtained in the step 1.3 for 0.5-3 h, washing, drying and screening to obtain sodium-containing basic nickel carbonate NaNi₄(CO₃)₃(OH)₃·3H₂O。

9. The method for preparing the Cr-doped sodium nickel phosphate photocatalytic material according to claim 8, wherein in the step 1.2, the reaction temperature is 50-60 ℃ and the reaction time is 30-60 min.

10. The method for preparing the Cr-doped sodium nickel phosphate photocatalytic material according to any one of claims 9, wherein in the step 1.3, the reaction temperature is 50-60 ℃ and the reaction time is 11-30 hours.

Technical Field

The invention belongs to the technical field of preparation of nickel sodium phosphate photocatalytic materials, and particularly relates to a Cr-doped nickel sodium phosphate photocatalytic material and a preparation method thereof.

Background

The photocatalytic technology is a basic nanotechnology which was born in the 70 th century, and in mainland China we will use the common term photocatalyst as a name for photocatalyst. The typical natural photocatalyst is the chlorophyll which is commonly seen in the plants, and promotes carbon dioxide and water in the air to be a mixture of oxygen and carbohydrate in the photosynthesis of the plants. The photocatalyst can be used in a plurality of advanced fields such as environmental purification, self-cleaning materials, advanced new energy, cancer medical treatment, high-efficiency antibiosis and the like.

Numerous materials are available worldwide as photocatalysts, including titanium dioxide (TiO)₂) Zinc oxide (ZnO), tin oxide (SnO)₂) Zirconium dioxide (ZrO)₂) And various oxide sulfide semiconductors such as cadmium sulfide (CdS). Cadmium sulfide (CdS) and zinc oxide (ZnO) are used as photocatalyst materials, but because the chemical properties of the cadmium sulfide (CdS) and the zinc oxide (ZnO) are unstable, the cadmium sulfide (CdS) and the zinc oxide (ZnO) can be dissolved by light during photocatalysis, and dissolved harmful metal ions have certain biological toxicity, so developed countries rarely use the cadmium sulfide (CdS) and the zinc oxide (ZnO) as civil photocatalytic materials at present, wherein titanium dioxide is more applied, but the band gap of the titanium dioxide determines that the titanium dioxide is difficult to realize photocatalysis under the condition of visible light; therefore, it is still a great challenge to find a photocatalytic material which is low in cost, safe, nontoxic, good in stability and easy to recycle.

Disclosure of Invention

In view of the above, the main object of the present invention is to provide a Cr-doped sodium nickel phosphate photocatalytic material and a preparation method thereof, which solve the problems of high cost, high toxicity and poor photocatalytic effect in the prior art.

To achieve the above objects, the inventionThe technical scheme is realized as follows: a Cr-doped sodium nickel phosphate photocatalytic material has a substrate material with a chemical formula of Na₄Ni₃P₄O₁₅And the surface of the substrate material is doped with Cr salt.

The other technical scheme of the invention is realized as follows: a preparation method of a Cr-doped sodium nickel phosphate photocatalytic material is realized by the following steps:

step 1, adding sodium-containing basic nickel carbonate into a phosphoric acid solution for a dissolution reaction to obtain a sodium-containing nickel phosphate solution;

step 2, adding a chromium salt into the sodium-containing nickel phosphate solution obtained in the step 1, stirring for reaction, and then carrying out concentration crystallization to obtain a Cr-doped nickel sodium phosphate crystal mixture;

and 3, calcining the Cr-doped sodium nickel phosphate crystal mixture obtained in the step 2, and cooling to obtain the Cr-doped sodium nickel phosphate photocatalytic material.

Preferably, in the step 1, the molar ratio of the basic nickel carbonate containing sodium to the phosphoric acid in the phosphoric acid solution is (1.0-1.3): 1.

preferably, in the step 2, the molar ratio of the added chromium salt to the basic nickel carbonate containing sodium is (0.015-0.33): 1.

preferably, in the step 2, the chromium salt is at least one of chromium sulfate, chromium chloride and chromium nitrate.

Preferably, in the step 2, the stirring reaction time is 3-5 h.

Preferably, in the step 3, the calcination temperature is 300-.

Preferably, in the step 1, the specific preparation method of the basic nickel carbonate containing sodium is as follows:

step 1.1, simultaneously adding a sodium carbonate solution with the concentration of 180-300 g/L and a nickel sulfate solution with the concentration of 60-100 g/L into a reactor, and obtaining basic nickel carbonate slurry after adjusting the pH value of a flow control system of the sodium carbonate solution and the nickel sulfate solution to be 8.2-8.3 and reacting for 20-25 h at 50-60 ℃ in the feeding process, wherein the flow of the sodium carbonate solution is 100-1000L/h, and the flow of the nickel sulfate solution is 100-1000L/h;

step 1.2, stopping adding the sodium carbonate solution and the nickel sulfate solution into the reactor, and controlling the crystal form transformation of the basic nickel carbonate in the basic nickel carbonate slurry obtained in the step 1.1 by adjusting the reaction temperature and the reaction time to obtain hydrated sodium nickel carbonate seed crystals;

step 1.3, adding the sodium carbonate solution and the nickel sulfate solution into the reactor again, wherein the pH value of a flow control system of the sodium carbonate solution and the nickel sulfate solution is adjusted to be 8.5-8.8 in the feeding process, and the growth of the hydrated nickel carbonate crystal seed obtained in the step 1.2 is controlled by adjusting the reaction temperature and the reaction time to obtain a crude sodium-containing basic nickel carbonate product;

step 1.4, sequentially aging the crude sodium-containing basic nickel carbonate product obtained in the step 1.3 for 0.5-3 h, washing, drying and screening to obtain sodium-containing basic nickel carbonate NaNi₄(CO₃)₃(OH)₃·3H₂O。

Preferably, in the step 1.2, the reaction temperature is 50-60 ℃, and the reaction time is 30-60 min.

Preferably, in the step 1.3, the reaction temperature is 50-60 ℃ and the reaction time is 11-30 h.

Preferably, the washing in the step 1.4 adopts pure water, the temperature of the pure water is 70-85 ℃, and the conductivity of the pure water is less than or equal to 100 mu s/m.

Preferably, the drying temperature in the step 1.4 is 95-105 ℃, and the drying time is 2-3 h; and screening by adopting a 200-400-mesh sieve.

Compared with the prior art, the method for preparing the chromium-doped nickel sodium phosphate photocatalytic material by selecting the hydrated carbon nickel sodium, the phosphoric acid and the chromium salt effectively avoids the introduction of other impurities, improves the purity of the synthesized nickel sodium phosphate, and simultaneously improves the photocatalytic activity of the synthesized nickel sodium phosphate; by doping Cr salt on the surface of the nickel sodium phosphate, the corresponding range of the nickel sodium phosphate in ultraviolet and visible light regions is effectively widened, the structure of the nickel sodium phosphate is influenced to form lattice defects, and the separation of photo-generated electron pairs is facilitated; the method disclosed by the invention is a green reaction, does not need a complex process, is simple to control, is low in cost, is easy for batch production, and can quickly realize industrialization.

Drawings

FIG. 1 is an SEM image of a Cr-doped sodium nickel phosphate photocatalytic material obtained in example 1 of the present invention;

FIG. 2 is a graph showing a change in degradation rate of ciprofloxacin by the Cr-doped sodium nickel phosphate photocatalytic material obtained in example 1 of the present invention;

FIG. 3 is a graph showing the degradation rate change of ciprofloxacin by the Cr-doped sodium nickel phosphate photocatalytic material obtained in example 2 of the present invention;

fig. 4 is a graph showing a degradation rate change of ciprofloxacin by the Cr-doped sodium nickel phosphate photocatalytic material obtained in example 3 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The chemical formula of the base material of the Cr-doped sodium nickel phosphate photocatalytic material provided by the embodiment of the invention is Na₄Ni₃P₄O₁₅And the surface of the substrate material is doped with Cr salt.

The embodiment of the invention also provides a preparation method of the Cr-doped sodium nickel phosphate photocatalytic material, which is realized by the following steps:

step 1, adding sodium-containing basic nickel carbonate into a phosphoric acid solution for a dissolution reaction to obtain a sodium-containing nickel phosphate solution, wherein the molar ratio of the sodium-containing basic nickel carbonate to phosphoric acid is (1.0-1.3): 1;

the specific preparation method of the basic nickel carbonate containing sodium comprises the following steps:

step 1.1, simultaneously adding a sodium carbonate solution with the concentration of 180-300 g/L and a nickel sulfate solution with the concentration of 60-100 g/L into a reactor, adjusting the flow rate of the sodium carbonate solution to be 100-1000L/h and the flow rate of the nickel sulfate solution to be 100-1000L/h in the feeding process, so as to control the pH value of a system to be 8.2-8.3, and reacting for 20-25 h at the temperature of 60-90 ℃ to obtain basic nickel carbonate;

step 1.2, stopping adding a sodium carbonate solution and a nickel sulfate solution into the reactor, reacting the basic nickel carbonate obtained in the step 1.1 at 50-60 ℃ for 30-60 min, and feeding the basic nickel carbonate after the reaction is stopped to cause the surface energy of the product to change, so as to obtain hydrated nickel sodium carbonate crystal seeds;

step 1.3, adding a sodium carbonate solution and a nickel sulfate solution into the reactor again, controlling the pH value of the system to be 8.5-8.8, reacting hydrated sodium nickel carbonate crystal seeds for 11-30 h at 50-60 ℃, promoting the growth of crystal nuclei, and obtaining a sodium-containing basic nickel carbonate crude product;

and step 1.4, sequentially aging the crude sodium-containing basic nickel carbonate obtained in the step 1.3 for 0.5-3 h, washing with pure water with the conductivity of less than or equal to 100 mu s/m and the temperature of 70-85 ℃, drying at 95-105 ℃ for 2-3 h, and finally screening with a 200-400-mesh sieve to obtain the sodium-containing basic nickel carbonate.

And 2, adding a chromium salt into the sodium-containing nickel phosphate solution obtained in the step 1, stirring and reacting for 3-5 hours, and then concentrating and crystallizing to obtain a Cr-doped nickel sodium phosphate crystal mixture, wherein the molar ratio of the addition amount of the chromium salt to the sodium-containing basic nickel carbonate is (0.015-0.33): 1; the chromium salt is at least one of chromium sulfate, chromium chloride and chromium nitrate

And 3, calcining the Cr-doped sodium nickel phosphate crystal mixture obtained in the step 2 at the temperature of 300-800 ℃ for 2-10 h, and cooling to obtain the Cr-doped sodium nickel phosphate photocatalytic material.

According to the method for preparing the chromium salt doped nickel sodium phosphate photocatalytic material by selecting the hydrated carbon nickel sodium, the phosphoric acid and the chromium salt, the introduction of other impurities is effectively avoided, the purity of the synthesized nickel sodium phosphate is improved, and the photocatalytic activity of the synthesized nickel sodium phosphate is also improved; by doping Cr salt on the surface of the nickel sodium phosphate, the corresponding range of the nickel sodium phosphate in ultraviolet and visible light regions is effectively widened, the structure of the nickel sodium phosphate is influenced to form lattice defects, and the separation of photo-generated electron pairs is facilitated; the method disclosed by the invention is a green reaction, does not need a complex process, is simple to control, is low in cost, is easy for batch production, and can quickly realize industrialization.