Bi for degrading organic matters in response to visible light2MoO6Preparation method of/CuS heterojunction photocatalytic material
阅读说明：本技术 一种可见光响应降解有机物的Bi2MoO6/CuS异质结光催化材料的制备方法 (Bi for degrading organic matters in response to visible light2MoO6Preparation method of/CuS heterojunction photocatalytic material ) 是由 潘松楠 李文江 于 2021-09-23 设计创作，主要内容包括：本发明属于半导体材料制备技术领域,特指一种异质结光催化剂的制备方法和用途。以钼酸纳,硝酸铋、硝酸铜和硫代硫酸钠为原料,经溶剂热法制备出不同摩尔比的Bi-(2)MoO-(6)/CuS异质结光催化剂,分别考察它们以相同催化剂量(15mg)条件,在可见光照射下对有机污染物罗丹明B(30mg/L)的降解效果,光催化结果显示少量的硫化铜与钼酸铋复合制备出的Bi-(2)MoO-(6)/CuS异质结光催化剂能够显著提高光催化活性。(The invention belongs to the technical field of semiconductor material preparation, and particularly relates to a preparation method and application of a heterojunction photocatalyst. Preparing Bi with different molar ratios by taking sodium molybdate, bismuth nitrate, copper nitrate and sodium thiosulfate as raw materials through a solvothermal method 2 MoO 6 the/CuS heterojunction photocatalysts are respectively examined for the degradation effect of the same catalyst amount (15mg) on organic pollutant rhodamine B (30mg/L) under the irradiation of visible light, and the photocatalysis result shows that a small amount of Bi prepared by compounding copper sulfide and bismuth molybdate 2 MoO 6 the/CuS heterojunction photocatalyst can obviously improve the photocatalytic activity.)
1. Bi for degrading organic matters in response to visible light2MoO6The preparation method of the/CuS heterojunction photocatalytic material is characterized by comprising the following steps:
(1) weighing sodium thiosulfate and copper nitrate in absolute ethyl alcohol, stirring to obtain a suspension, transferring the suspension to a 50ml reaction kettle, reacting in an oven, and finally washing, filtering and drying to obtain copper sulfide.
(2) Weighing sodium molybdate and bismuth nitrate, respectively dissolving in ethylene glycol, slowly dripping the obtained sodium molybdate aqueous solution into the bismuth nitrate aqueous solution to obtain milky suspension, adding 60ml ethanol, and stirring for a period of time. And finally, transferring the obtained mixed solution to a 100ml reaction kettle to react in an oven, and then washing, filtering and drying to obtain pure bismuth molybdate.
(3) Weighing copper sulfide, sodium molybdate and bismuth nitrate, respectively dissolving in ethanol and ethylene glycol, slowly dripping the obtained sodium molybdate solution into the bismuth nitrate solution to obtain milky suspension, and then pouring the prepared copper sulfide ethanol solution into the suspension and stirring. Finally transferring the mixed solution to a 100ml reaction kettle for reaction in a drying oven, and finally obtaining Bi through washing, filtering and drying2MoO6a/CuS heterojunction photocatalyst.
2. The Bi according to claim 12MoO6The preparation method of the/CuS heterojunction photocatalytic material is characterized by comprising the following steps: the concentration of the sodium thiosulfate in the step (1) is 1-1.5M, the concentration of the copper nitrate is 0.5-0.7M, the hydrothermal reaction temperature is 60-80 ℃, and the time is 4 hours.
3. The Bi according to claim 12MoO6The preparation method of the/CuS heterojunction photocatalytic material is characterized by comprising the following steps: in the step (2), 0.25-0.45 g of sodium molybdate and 1.25-1.65 g of bismuth nitrate. The solvothermal reaction temperature is 160-190 ℃, and the time is 24 hours.
4. The Bi according to claim 12MoO6The preparation method of the/CuS heterojunction photocatalytic material is characterized by comprising the following steps: in the step (3), 0.1-0.5 g of copper sulfide is dissolved in 60ml of ethanol solution; the mass of sodium molybdate is 0.25-0.45 g, and the sodium molybdate is dissolved in 10 ethylene glycol; the mass of the bismuth nitrate is 1.25-1.65 g, the bismuth nitrate is dissolved in 10ml of ethylene glycol, the solvothermal reaction temperature is 160-190 ℃, and the solvothermal reaction time is 24 hours.
Technical Field
The invention belongs to the field of semiconductor material preparation and photocatalysis, and provides a Bi synthesized by a simple solvothermal method for degrading organic matters in response to visible light2MoO6a/CuS type heterojunction photocatalyst.
Background
In recent years, semiconductor photocatalysis technology is widely researched due to the advantages of high efficiency, energy conservation, complete pollutant degradation and the like, and the photocatalysis technology is considered to solve the problem of water pollution at present due to the fact that solar energy can be utilized to the maximum extent to degrade and eliminate organic wastewaterThe ideal method of (1). The technology utilizes the semiconductor photocatalyst to generate photoproduction electron-hole pairs with higher oxidation reduction capability under the irradiation of a specific light source so as to realize the high-efficiency degradation of organic pollutants. However, the most studied semiconductor photocatalysts are currently, such as: TiO 22、BiPO4When ultraviolet light response materials (ultraviolet light only accounts for about 5% of solar spectrum), the development of semiconductor photocatalysis technology is limited to a great extent due to low solar energy utilization efficiency, so that the development of novel and efficient visible light response semiconductor photocatalysts is a hotspot in the field of photocatalysis research.
The visible light response material is used for constructing the copper sulfide heterostructure photocatalyst, and the method is a simple and effective method for improving the photocatalytic performance. Such heterostructure interfaces not only help to widen the light trapping window, but also can extend the lifetime of the photogenerated carriers. Recently, Bi-containing oxides have attracted much attention in the fields of photocatalysis and energy conversion due to their layered structure and inherent characteristics. In particular bismuth molybdate from alternating (MoO)4)2-Flakes and (Bi)2O2)2+The layers are made up such that they have a controlled morphology and a suitable band gap to capture visible light. The band gap matching of the copper sulfide and the bismuth molybdate can form a heterostructure to block the recombination of photo-generated electron-hole pairs, so that the bismuth molybdate becomes an ideal promoter of the copper sulfide. Bi prepared as Muwei (front. environ. Sci. Eng.2021, 15 (4): 52)2MoO6/CuS composite nanoparticle heterojunction with pure CuS and Bi2MoO6The heterojunction exhibits enhanced chromium ion removal under visible light, compared to the photocatalytic activity of (a).
It is well known that morphology and structure also affect the photocatalytic performance of the catalyst. Three-dimensional layered structures composed of two-dimensional layered nanostructures and one-dimensional materials are currently receiving great attention in the fields of adsorption and photocatalysis. MoO prepared as by the Lumingxing team (ACS appl. Mater. interfaces 2014, 6, 12, 9004-3Nanosheet and TiO2MoO with RhB photocatalytic degradation activity ratio shown by nanofiber composite material3Nanoparticles and TiO2The composite material of the nanofiber is improved by 3 times. Zhouweijia and colleagues (small 2013, 9, No.1, 140-147) prepare a heterostructure photocatalyst for constructing a plurality of molybdenum disulfide nanosheets on a titanium dioxide nanobelt, and the material can completely adsorb and degrade RhB under 20-minute illumination. According to many previous studies, three reasons why three-dimensional layered structures can effectively improve photocatalytic efficiency are probably as follows: (1) one-dimensional structures in the three-dimensional structure, such as nanowires, nanorods and nanotubes, can serve as charge transfer providing paths, thereby facilitating the separation of photoinduced electron-hole pairs; (2) the three-dimensional layered structure takes full advantage of light by causing multiple reflections of visible light. (3) The three-dimensional structure can provide a large surface area and numerous active sites, thereby promoting adsorption and photochemical reactions.
Based on the research, we firstly propose that a solvothermal method is adopted to assemble two-dimensional bismuth molybdate nanosheets on the surface of a one-dimensional copper sulfide nanorod so as to synthesize three-dimensional Bi2MoO6a/CuS layered heterojunction photocatalyst.
Disclosure of Invention
The invention aims to provide Bi for degrading organic matters in response to visible light2MoO6The method uses sodium thiosulfate, copper nitrate, copper chloride, sodium molybdate and bismuth nitrate as raw materials to synthesize the visible-light-responsive Bi by a hydrothermal method2MoO6the/CuS heterostructure photocatalyst is applied to degrading organic pollutant rhodamine B under visible light.
The invention provides a visible light responding Bi2MoO6The preparation method of the/CuS heterojunction photocatalytic material is characterized by comprising the following steps:
(1) preparing copper sulfide: weighing sodium thiosulfate and copper nitrate in absolute ethyl alcohol, stirring to obtain a suspension, transferring the suspension to a 50ml reaction kettle, reacting in an oven, and finally washing, filtering and drying to obtain copper sulfide.
The preparation of the copper sulfide is a conventional technical means. The concentration of the sodium thiosulfate is 1-1.5M, the concentration of the copper nitrate is 0.5-0.7M, the hydrothermal reaction temperature is 60-80 ℃, and the time is 4 hours.
(2) Weighing sodium molybdate and bismuth nitrate, respectively dissolving in ethylene glycol, slowly dripping the obtained sodium molybdate aqueous solution into the bismuth nitrate aqueous solution to obtain milky suspension, adding 60ml ethanol, and stirring for a period of time. And finally, transferring the obtained mixed solution to a 100ml reaction kettle to react in an oven, and then washing, filtering and drying to obtain pure bismuth molybdate.
The preparation of the bismuth molybdate is a conventional technical means. 0.25-0.45 g of sodium molybdate and 1.25-1.65 g of bismuth nitrate. The solvothermal reaction temperature is 160-190 ℃, and the time is 24 hours.
(3) Weighing copper sulfide, sodium molybdate and bismuth nitrate, respectively dissolving in ethylene glycol, slowly dripping the obtained sodium molybdate solution into the bismuth nitrate solution to obtain milky suspension, and then pouring the prepared copper sulfide ethanol solution into the suspension and stirring. Finally transferring the mixed solution to a 100ml reaction kettle for reaction in a drying oven, and finally obtaining Bi through washing, filtering and drying2MoO6a/CuS heterojunction photocatalyst.
Bi in the invention2MoO6The crystal structure of the/CuS heterojunction photocatalyst is determined by a powder X-ray diffractometer (XRD), as shown in figure 1, the XRD diffraction peak of CuS corresponds to a standard card 06-0464, and Bi is2MoO6The XRD diffraction peak of the compound accords with that of the standard card 21-0102; for Bi2MoO6For the/CuS heterostructure, Bi can be obviously observed in the XRD spectrum2MoO6And a CuS two-phase material, and the diffraction peak intensity of CuS gradually becomes stronger as the molar ratio of bismuth molybdate to copper oxide is reduced. The XRD diffraction pattern shows that Bi2MoO6the/CuS heterojunction photocatalyst has been successfully prepared by a solvothermal method.
Bi in the invention2MoO6The morphological size and microstructure of the/CuS heterojunction photocatalyst are determined by a Field Emission Scanning Electron Microscope (FESEM), as shown in fig. 2, CuS possesses a rod-like morphology and a relatively rough surface, which is favorable for crystal nucleus growth; bi2MoO6The nano-sphere is formed by assembling nano-sheets, and has a relatively large specific surface area and can absorb more visible light; bismuth molybdate in FIG. twoThe composite material with copper sulfide can clearly see that the two are in close interfacial contact, and therefore, the fact that a heterostructure is formed between bismuth molybdate and copper sulfide can be inferred.
The purpose of the invention is as follows: firstly, providing and preparing Bi2MoO6A method of a CuS heterojunction photocatalyst; II, mixing Bi2MoO6the/CuS is used as a photocatalytic material for photocatalytic degradation of organic pollutant rhodamine B under visible light.
Bi prepared by solvothermal method2MoO6the/CuS heterojunction photocatalyst shows excellent photocatalytic degradation activity on rhodamine B under visible light; the method has the advantages of simple process operation, low cost and short reaction period, and can effectively degrade organic pollutants by photocatalysis to achieve the aim of environmental remediation.
Drawings
FIG. 1 is an XRD diffraction pattern of a sample prepared by the present invention, in which Bi is contained2MoO6the/CuS heterojunction photocatalyst respectively shows Bi2MoO6And characteristic peaks of the CuS component.
FIG. 2 shows Bi prepared by the present invention2MoO6The appearance and microstructure of the prepared sample can be obviously observed from a Field Emission Scanning Electron Microscope (FESEM) image of the/CuS heterojunction photocatalyst.
FIG. 3 is a diagram showing the effect of photocatalytic degradation of an organic pollutant rhodamine B by a sample prepared by the method of the invention under visible light. Pure Bi can be seen in the figure2MoO6CuS has low degradation efficiency on organic pollutant rhodamine B under visible light, and Bi2MoO6the/CuS heterojunction photocatalyst shows higher photocatalytic degradation efficiency. Illustrating the Bi produced2MoO6the/CuS heterojunction photocatalyst can remarkably improve the photocatalytic performance and can be well applied to the degradation of organic pollutants.
Detailed Description
The present invention is further illustrated by the following specific examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.
Example 1
(1): 139mg of copper nitrate trihydrate are weighed to be dissolved in 20ml of absolute ethanol, and 142.8mg of sodium thiosulfate are weighed to be dissolved in 20ml of absolute ethanol. And pouring the prepared copper nitrate aqueous solution into a sodium thiosulfate solution, stirring for 30min to dissolve the copper nitrate aqueous solution to obtain a suspension, transferring the suspension into a 50ml reaction kettle, reacting for 24 hours in an oven at 70 ℃, and finally washing, filtering and drying to obtain the copper sulfide.
(2): 0.363g of sodium molybdate and 1.455g of bismuth nitrate are weighed and respectively dissolved in 10ml of ethylene glycol, the obtained sodium molybdate solution is slowly dripped into the bismuth nitrate solution to obtain milky suspension A, and then 60ml of absolute ethyl alcohol is poured into the milky suspension A and is stirred for 30min for full mixing to obtain mixed solution B. And finally, transferring the mixed solution B into a 100ml reaction kettle, reacting for 24 hours in an oven at 180 ℃, and finally washing, filtering and drying to obtain the bismuth molybdate.
(3): weighing 0.165g of copper sulfide, dissolving the copper sulfide in 60ml of absolute ethyl alcohol to obtain a mixed solution A, weighing 0.363g of sodium molybdate, dissolving 1.455g of bismuth nitrate in 10ml of absolute ethyl alcohol respectively, slowly dropping the obtained sodium molybdate solution into the bismuth nitrate solution to obtain a milky suspension B, pouring the obtained mixed solution A into the suspension B, and stirring for 30min for full mixing to obtain a mixed solution C. Finally, the mixed solution C is transferred to a 100ml reaction kettle, reacts for 24 hours in an oven at 180 ℃, and finally Bi is obtained through water washing, filtering and drying2MoO6a/CuS heterojunction photocatalyst.
Example 2
(1): 139mg of cupric chloride dihydrate are weighed out and dissolved in 20ml of absolute ethyl alcohol, and 142.8mg of sodium thiosulfate are weighed out and dissolved in 20ml of absolute ethyl alcohol. And pouring the prepared copper chloride aqueous solution into a sodium thiosulfate solution, stirring for 30min to dissolve the copper chloride aqueous solution to obtain a suspension, transferring the suspension into a 50ml reaction kettle, reacting for 4 hours in an oven at 70 ℃, and finally washing, filtering and drying to obtain the copper sulfide.
(2): 0.363g of sodium molybdate and 1.455g of bismuth nitrate are weighed and respectively dissolved in 10ml of ethylene glycol, the obtained sodium molybdate solution is slowly dripped into the bismuth nitrate solution to obtain milky suspension A, and then 60ml of absolute ethyl alcohol is poured into the milky suspension A and is stirred for 30min for full mixing to obtain mixed solution B. And finally, transferring the mixed solution B into a 100ml reaction kettle, reacting for 24 hours in an oven at 180 ℃, and finally washing, filtering and drying to obtain the bismuth molybdate.
(3): weighing 0.165g of copper sulfide, dissolving the copper sulfide in 60ml of absolute ethyl alcohol to obtain a mixed solution A, weighing 0.363g of sodium molybdate, dissolving 1.455g of bismuth nitrate in 10ml of absolute ethyl alcohol respectively, slowly dropping the obtained sodium molybdate solution into the bismuth nitrate solution to obtain a milky suspension B, pouring the obtained mixed solution A into the suspension B, and stirring for 30min for full mixing to obtain a mixed solution C. Finally, the mixed solution C is transferred to a 100ml reaction kettle, reacts for 24 hours in an oven at 180 ℃, and finally Bi is obtained through water washing, filtering and drying2MoO6a/CuS heterojunction photocatalyst.
Example 3
(1): 139mg of cupric chloride dihydrate are weighed out and dissolved in 20ml of absolute ethyl alcohol, and 142.8mg of sodium thiosulfate are weighed out and dissolved in 20ml of absolute ethyl alcohol. And pouring the prepared copper chloride aqueous solution into a sodium thiosulfate solution, stirring for 30min to dissolve the copper chloride aqueous solution to obtain a suspension, transferring the suspension into a 50ml reaction kettle, reacting for 4 hours in an oven at 70 ℃, and finally washing, filtering and drying to obtain the copper sulfide.
(2): weighing 0.300g of hexadecyl trimethyl ammonium bromide (CTAB) and dissolving in 60ml of deionized water, weighing 0.242g of sodium molybdate and 0.970g of bismuth nitrate and dissolving in 10ml of deionized water respectively, slowly dropping the obtained sodium molybdate aqueous solution into the bismuth nitrate aqueous solution to obtain milky suspension A, and then pouring the obtained CTAB solution into the suspension A and stirring for 30min for full mixing to obtain a mixed solution B. And finally, transferring the mixed solution B into a 100ml reaction kettle, reacting for 24 hours in an oven at 180 ℃, and finally washing, filtering and drying to obtain the bismuth molybdate.
(3): weighing 0.300g of hexadecyl trimethyl ammonium bromide (CTAB) and 0.165g of copper sulfide, simultaneously dissolving the hexadecyl trimethyl ammonium bromide and the copper sulfide in 60ml of deionized water to obtain a mixed solution A, weighing 0.242g of sodium molybdate, respectively dissolving 0.970g of bismuth nitrate in 10ml of deionized water, and slowly dropping the obtained sodium molybdate aqueous solution into the bismuth nitrate aqueous solution to obtain milky white bismuth nitrate aqueous solutionAnd pouring the obtained mixed solution A into the suspension B, and stirring for 30min for fully mixing to obtain a mixed solution C. Finally, the mixed solution C is transferred to a 100ml reaction kettle, reacts for 24 hours in an oven at 180 ℃, and finally Bi is obtained through water washing, filtering and drying2MoO6a/CuS heterojunction photocatalyst.
Bi is prepared by regulating and controlling the molar ratio of sodium molybdate, bismuth nitrate and copper oxide2MoO6the/CuS heterojunction photocatalysts are respectively inspected to have the same catalytic amount (15mg) and have the degradation effect on organic pollutant rhodamine B (30mg/L) under the irradiation of visible light, and the photocatalysis result shows that a small amount of sodium molybdate and copper oxide are compounded to prepare Bi2MoO6the/CuS heterojunction photocatalyst can obviously improve the photocatalytic activity. In addition, the heterojunction photocatalyst with the molar ratio of Bi to Cu of 0.72 shows the highest photocatalytic performance, namely under illumination of 180min, the degradation efficiency of rhodamine B can reach 87%; illustrating the Bi produced2MoO6the/CuS heterojunction photocatalyst has excellent visible light catalytic performance and can be applied to efficient treatment of organic pollutants in water. Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that: various substitutions, changes and modifications are possible without departing from the spirit and scope of the invention and the appended claims, and therefore the scope of the invention is not limited to the embodiments disclosed.