Method for preparing bismuth oxychloride nanoflowers through tea saponin induction and application of bismuth oxychloride nanoflowers

Abstract

The invention belongs to the technical field of preparation of nano-catalysts, and discloses a method for preparing bismuth oxychloride nano-flowers through tea saponin induction and application of the bismuth oxychloride nano-flowers. The method comprises the following steps: mixing a bismuth source, a chlorine source and a solvent, then adding tea saponin, mixing, carrying out a heating reaction, and separating to prepare the bismuth oxychloride nanoflower, the preparation method of the tea saponin comprises the following steps: mixing tea seed meal powder with water, carrying out water bath extraction, and filtering to obtain filtrate; mixing the filtrate with aluminum sulfate or a hydrate of the aluminum sulfate, boiling, settling and centrifuging to obtain supernate, and then adding activated carbon for decoloration to obtain decolorized supernate; boiling and concentrating the decolorized supernatant, cooling, and adding absolute ethyl alcohol to obtain a conversion extraction solution containing flocculent precipitate; and concentrating and drying to obtain the tea saponin. According to the method disclosed by the invention, the bismuth oxychloride nanoflowers are prepared through induction of the tea saponin, and the prepared bismuth oxychloride nanoflowers have a good catalytic oxidation diesel oil desulfurization effect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nanocatalyst preparation, and particularly relates to a method for preparing bismuth oxychloride nanoflowers induced by tea saponin and application thereof. BACKGROUND

[0002] Tea seed cake is a large amount of solid waste produced after tea seed oil is pressed, and is treated as a feed additive, organic fertilizer and the like with extremely low added value for a long time. The active ingredients cannot be fully developed and utilized. Tea saponin is a natural pentacyclic triterpene saponin compound extracted from tea seed cake, has multiple biological activities such as surface activity, antibacterial activity and anti-inflammatory activity, and can be used for preparing green and non-pollution non-ionic detergents such as shampoo, hand sanitizer, cleaning agent and emulsifier and the like according to the excellent surface activity. With the increasing demand of people for natural and green products, the research on tea saponin is active in recent years, but mainly focuses on the development and application of purification and extraction technology, biological control and pharmacological activity, and the research on the application in the field of chemical production is relatively insufficient, and has good development prospect.

[0003] For example, patent CN 107418178 A discloses a tea saponin modified phosphorus slag and a composite floor tile made of the modified phosphorus slag and waste plastic. The modified phosphorus slag is composed of 6-13wt% tea saponin and 87-94wt% phosphorus, and the composite floor tile is made of waste polycarbonate plastic and the modified phosphorus slag. The composite floor tile is made of 20-25 parts of waste polycarbonate plastic, 75-80 parts of tea saponin modified phosphorus slag, and is formed into a sheet through drying, stirring, plasticizing, molding and cutting. The application greatly improves the performance of the composite floor tile, and increases the filling amount of phosphorus slag in the composite floor tile, thereby effectively reducing the cost of the product.

[0004] Patent CN 106259346 A discloses a preparation method of a pesticide composition containing fluopyram and tea saponin. The active ingredients of the pesticide composition contain fluopyram and tea saponin, and the weight ratio of fluopyram to tea saponin is 1:50-40:1, and preferably 1:10-20:1. The two active ingredients in the composition of the application can interact with each other to improve the control effect, reduce the amount of pesticide used, and are safe to the environment.

[0005] Patent CN 112998263 A discloses a preparation method of oil tea saponin microcapsules with alcoholism relieving function. The optimal ratio is determined by orthogonal test with tea saponin, white sugar, beta-cyclodextrin and xanthan gum as single factors, and the mixture is filtered and then filled into a tank. Soybean protein isolate and malt dextrin are mixed as wall material, tea saponin alcoholism relieving liquid is added, and the mixture is sheared at 9995-10000r / min for 3-8min, and then high-pressure homogenization and spray drying are performed to obtain the product. The application provides an oil tea saponin microcapsule preparation method with alcoholism relieving and cholesterol reducing functions, simple method and convenient tea cake recycling.

[0006] In summary, the research on tea saponin involves building materials, pesticides, medicine and other fields.

[0007] Therefore, it is necessary to further develop the application field of tea saponin. SUMMARY

[0008] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a method for inducing preparation of bismuth oxychloride nanoflower by tea saponin and application thereof. The method of the present application utilizes tea saponin to induce preparation of bismuth oxychloride nanoflower, and the prepared bismuth oxychloride nanoflower has good effect of catalytic oxidation of diesel desulfurization.

[0009] The first aspect of the present application provides a method for inducing preparation of bismuth oxychloride nanoflower by tea saponin.

[0010] A method for inducing preparation of bismuth oxychloride nanoflower by tea saponin, comprising the following steps: Mixing a bismuth source, a chlorine source and a solvent, then adding tea saponin, mixing, heating reaction, separation, to obtain the bismuth oxychloride nanoflower; The preparation method of the tea saponin comprises the following steps: (1) mixing tea dregs powder and water, water bath extraction, filtration, to obtain first filtrate and filter residue a, mixing the filter residue a and water for extraction, filtration, to obtain second filtrate and filter residue b, mixing the filter residue b and water for extraction, filtration, to obtain third filtrate and filter residue c, combining the first filtrate, the second filtrate and the third filtrate, to obtain filtrate; (2) mixing the filtrate of step (1) and aluminum sulfate or aluminum sulfate hydrate, boiling, settling, centrifugation, to obtain supernatant, then adding activated carbon for decolorization, to obtain decolorized supernatant; (3) boiling and concentrating the decolorized supernatant of step (2), then adding anhydrous ethanol after cooling, to obtain a transfer solution containing flocculent precipitate; (4) heating the transfer solution containing flocculent precipitate obtained in step (3) for concentration, drying, to obtain the tea saponin.

[0011] Preferably, in step (1), the solid-liquid volume ratio of the tea dregs powder to water is 1: (3-4). For example, 1:3, 1:4.

[0012] Preferably, in step (1), the temperature of the water bath extraction is 80-85℃, and the time is 50-60 minutes.

[0013] Preferably, in step (1), the volume ratio of the filter residue a to water during the mixing extraction is 1: (2-3), and the mixing extraction time is 20-30 minutes.

[0014] Preferably, in step (1), the volume ratio of the filter residue b to water is 1: (2-3) during the mixing and leaching process, and the mixing and leaching time is 20-30 minutes.

[0015] Preferably, in step (1), the pH of the filtrate is 6-6.5.

[0016] Preferably, in step (2), the aluminum sulfate hydrate is aluminum sulfate octadecahydrate.

[0017] Preferably, in step (2), the ratio of the filtrate of step (1) to aluminum sulfate or aluminum sulfate hydrate is (170-180) mL: (2-2.5) g.

[0018] Preferably, in step (2), the boiling time is 3-5 minutes.

[0019] Preferably, in step (2), the centrifugation speed is 4000-6000 r / min, and the centrifugation time is 1-5 minutes.

[0020] Preferably, in step (2), the settling time is 1-2 hours.

[0021] Preferably, in step (2), the mass of the activated carbon is 1-2% of the mass of the supernatant. The activated carbon is wrapped with gauze to facilitate removal of the activated carbon.

[0022] Preferably, in step (4), the drying is carried out at 40-60°C for 3-5 hours.

[0023] Preferably, the method for preparing tea saponin comprises the following steps: First, gradient leaching: tea dregs powder (solid) and liquid (city supplied tap water) are leached at a solid-liquid ratio of 1:3-4 in a water bath at 80-85°C for 50-60 minutes, and then filtered while hot; the filter residue is subjected to two times of gradient water addition, with a solid-liquid ratio of 1:2 each time, the first time of gradient water addition is leached for 30 minutes, and the second time of gradient water addition is leached for 20 minutes, and the three times of filtrates are combined to obtain 170-180 mL (pH is about 6-6.5); Second, flocculation and impurity removal, activated carbon decolorization: 2-2.5 g of Al2(SO4)3·18H2O solid is added to the filtrate, boiled and stirred for 3-5 minutes, naturally settled for 1-2 hours, then centrifuged at 4000-6000 r / min for 1-5 minutes, about 150 ml of supernatant (pH≈5) is taken, 1-2% activated carbon (wrapped with gauze) is added to the supernatant, heated and stirred, and the activated carbon is removed after 5 minutes. Then, ethanol extraction: heating the decolorized supernatant to boiling, vaporizing and dehydrating it to a thick slurry, and then adding 2-3 times the volume of anhydrous ethanol to the thick slurry, so as to extract the residual water in the thick slurry into the ethanol, thereby obtaining an extraction solution containing a large amount of flocculent precipitate; Finally, drying and shaping: concentrating the extraction solution by heating and vaporizing it to a thick slurry, and then using the residual heat to precipitate tea saponin, and then transferring the thick slurry to a 70℃ oven after standing for about 20 minutes, and drying for 3-5 hours, and then grinding to obtain solid tea saponin.

[0024] Preferably, the bismuth source includes bismuth nitrate or a hydrate of bismuth nitrate.

[0025] Preferably, the chlorine source includes sodium chloride or potassium chloride. Preferably, the chlorine source includes sodium chloride.

[0026] Preferably, the mass ratio of the bismuth source to the chlorine source is 2.5-3.5: (0.3-0.4), and further preferably 2.9-3.0: (0.35-0.36).

[0027] Preferably, the solvent includes ethylene glycol.

[0028] Preferably, the heating reaction is carried out at a temperature of 140-180℃ for 8-12 hours.

[0029] Preferably, the separation includes the processes of suction filtration, washing, and drying.

[0030] Preferably, the washing is carried out using deionized water and then ethanol.

[0031] Preferably, the drying is carried out at 70-80℃ for 1-2 hours.

[0032] The second aspect of the present application provides a method for inducing the preparation of bismuth oxychloride nanoflowers from tea saponin.

[0033] A bismuth oxychloride nanoflower prepared by the above method.

[0034] The third aspect of the present application provides the use of the above method.

[0035] The use of the bismuth oxychloride nanoflower prepared by the above method in the field of desulfurization.

[0036] Preferably, the use includes the use in the desulfurization of diesel, gasoline, or kerosene.

[0037] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers, comprising the following steps: Mixing the bismuth oxychloride nanoflowers with an oxidizing agent, and then adding diesel and acetonitrile to carry out a desulfurization reaction.

[0038] Preferably, the diesel can be a simulated diesel containing 500 ppm of dibenzothiophene (DBT).

[0039] Preferably, a method for oxidizing desulfurization of bismuth oxychloride nanoflower, comprising the following steps: Take 0.04-0.06 g of bismuth oxychloride nanoflower in a two-port jacketed reaction bottle, then take 0.5 mL of 5% sodium hypochlorite solution (take before fully oscillating) as an oxidizing agent, fully oscillate the mixture, then add 10 mL of simulated diesel containing 500 ppm of dibenzothiophene (DBT), and finally add 2.5-5 mL of acetonitrile, and carry out desulfurization reaction, the temperature of the desulfurization reaction is 40-60℃, the stirring rate is 1.0-1.1 kr / min, and after 10-60 min of reaction time, sample detection of sulfide concentration is carried out to evaluate the catalyst performance of the bismuth oxychloride nanoflower.

[0040] Compared with the prior art, the present application has the following beneficial effects: (1) The present application provides a method for preparing bismuth oxychloride nanoflower, which is prepared by hydrothermal solvothermal method in ethylene glycol with tea saponin as an inducer; the obtained bismuth oxychloride is a nanoflower structure, the nanoflower diameter is 0.75-4.78 μm, the nanoflower petal length and width are 270-340 nm, and the thickness is 15-31 nm; under the same desulfurization rate, the catalyst turnover frequency (TOF) of the bismuth oxychloride nanoflower prepared by the present application for oxidizing desulfurization is increased by 2.4-3.2 times compared with the comparative example (without adding tea saponin).

[0041] (2) In the present application, tea saponin is directly extracted from waste tea seed cake, without additional modification, which can improve the catalytic activity of existing bismuth oxychloride, realize high-value utilization of waste, and provide a new method for improving the performance of catalyst. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The scanning electron microscope (SEM) image of the bismuth oxychloride nanoflower prepared in Example 2 of the present application; Figure 2 The scanning electron microscope (SEM) image of the bismuth oxychloride nanoflower prepared in Example 3 of the present application; Figure 3 The scanning electron microscope (SEM) image of the bismuth oxychloride nanosphere prepared in Comparative Example 1 of the present application; Figure 4 The scanning electron microscope (SEM) image of the bismuth oxychloride nanoflower prepared in Comparative Example 2 of the present application; Figure 5Fourier transform infrared spectroscopy (FTIR) of the BiOCl nanoflowers prepared in Example 2-3 of the present application and the BiOCl nanospheres prepared in Comparative Example 1 and the BiOCl nanoflowers prepared in Comparative Example 2; Figure 6 Thermogravimetric analysis (TGA) of the BiOCl nanoflowers prepared in Example 2-3 of the present application and the BiOCl nanospheres prepared in Comparative Example 1 and the BiOCl nanoflowers prepared in Comparative Example 2; Figure 7 Specific surface area (BET) and pore size analysis of the BiOCl nanoflowers prepared in Example 2 of the present application; Figure 8 Specific surface area (BET) and pore size analysis of the BiOCl nanoflowers prepared in Example 3 of the present application; Figure 9 Specific surface area (BET) and pore size analysis of the BiOCl nanospheres prepared in Comparative Example 1; Figure 10 Specific surface area (BET) and pore size analysis of the BiOCl nanospheres prepared in Comparative Example 2; Figure 11 Desulfurization rate comparison chart of the examples and comparative examples; Figure 12 XRD chart of BiOCl prepared under different conditions; Figure 13 XRD chart of self-made and purchased tea saponin. DETAILED DESCRIPTION

[0043] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0044] The raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0045] The preparation method of tea saponin used in the following examples is as follows: First, gradient extraction: tea meal powder (solid) and liquid (city supplied tap water) were mixed at a solid-liquid volume ratio of 1:4, and then extracted in a water bath at 80°C for 60 min, and filtered while hot; the filter residue was subjected to two times of gradient water addition, and the solid-liquid ratio was 1:2. The first time of gradient water addition was extracted for 30 min, and the second time of gradient water addition was extracted for 20 min. The three times of filtrates were combined to obtain 180 mL of filtrate (pH about 6-6.5); Secondly, flocculation impurity removal and activated carbon decolorization: 2.5 g of Al2(SO4)3·18H2O solid is added to the filtrate, and boiled and stirred for 5 min. After natural sedimentation for 2 h, centrifugation is performed at 5000 r / min for 3 min. About 150 mL of supernatant is taken, and 1.5% of activated carbon (wrapped with gauze) of the mass of the supernatant is added and heated and stirred. After 5 min, the activated carbon is removed, and a decolorized supernatant is obtained. Then, ethanol extraction: the decolorized supernatant is heated to boiling, and dehydrated by vaporization to a thick slurry. After cooling, 3 times the volume of anhydrous ethanol is added to the thick slurry, and the residual water in the thick slurry sample is extracted into the ethanol, to obtain an extraction solution containing a large amount of flocculent precipitate. Finally, drying and molding: the extraction solution is concentrated by heating and vaporization to a thick slurry, and the theasaponin is precipitated by utilizing the residual heat. After standing for 20 min, the thick slurry is transferred to a 70℃ oven and dried for 4 h. After cooling, the theasaponin powder is obtained by grinding. Example 1

[0046] A method for preparing bismuth oxychloride nanoflowers induced by theasaponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate is added to 70 mL of ethylene glycol, and fully stirred until dissolved. Then, 0.35 g of sodium chloride is added, stirred and dissolved, and then 0.3 g of the prepared theasaponin powder is added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160℃ for 12 h, cooled to room temperature, and filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral. The obtained filter cake is dried in an 80℃ oven for 1 h, to obtain bismuth oxychloride nanoflowers.

[0047] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers (40℃, 5 mL of acetonitrile), comprising the following steps: 0.05 g of bismuth oxychloride nanoflowers is weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (taken and fully shaken) is added as an oxidizing agent, the obtained mixture is fully shaken, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) is added, and finally 5 mL of acetonitrile is added, to perform a desulfurization reaction. The temperature of the desulfurization reaction is 40℃, the stirring rate is 1.0 kr / min, and after 10-60 min of reaction, the sulfide concentration is detected to evaluate the catalyst performance of the bismuth oxychloride nanoflowers. Example 2

[0048] A method for preparing bismuth oxychloride nanoflowers induced by theasaponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until dissolved, and then 0.5 g of prepared tea saponin powder was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral, and the obtained filter cake was dried in an oven at 80°C for 1 h to obtain bismuth oxychloride nanoflowers.

[0049] A method for oxidizing desulfurization of bismuth oxychloride nanoflowers (40°C, 5 mL of acetonitrile) includes the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (taken from the front and shaken well) was added as an oxidizing agent, the obtained mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 5 mL of acetonitrile was added for desulfurization reaction. The temperature of the desulfurization reaction was 40°C, the stirring rate was 1.0 kr / min, and the reaction time was 30 min. After sampling and detecting the concentration of sulfides, the catalyst performance of bismuth oxychloride nanoflowers was evaluated. Example 3

[0050] A method for preparing bismuth oxychloride nanoflowers induced by tea saponin includes the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until dissolved, and then 1.0 g of prepared tea saponin powder was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral, and the obtained filter cake was dried in an oven at 80°C for 1 h to obtain bismuth oxychloride nanoflowers.

[0051] A method for oxidizing desulfurization of bismuth oxychloride nanoflowers (40°C, 5 mL of acetonitrile) includes the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (taken from the front and shaken well) was added as an oxidizing agent, the obtained mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 5 mL of acetonitrile was added for desulfurization reaction. The temperature of the desulfurization reaction was 40°C, the stirring rate was 1.0 kr / min, and the reaction time was 30 min. After sampling and detecting the concentration of sulfides, the catalyst performance of bismuth oxychloride nanoflowers was evaluated. Example 4

[0052] A method for preparing bismuth oxychloride nanoflowers induced by tea saponin includes the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until dissolved, and then 1.2 g of prepared tea saponin powder was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral, and the obtained filter cake was dried in an 80°C oven for 1 h to obtain bismuth oxychloride nanoflowers.

[0053] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers (40°C, 5 mL of acetonitrile) includes the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (taken from the front and shaken well) was added as an oxidizing agent, the obtained mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 5 mL of acetonitrile was added for desulfurization reaction. The temperature of the desulfurization reaction was 40°C, the stirring rate was 1.0 kr / min, and the reaction time was 30 min. After sampling and detecting the concentration of sulfides, the catalyst performance of bismuth oxychloride nanoflowers was evaluated. Example 5

[0054] A method for preparing bismuth oxychloride nanoflowers induced by tea saponin includes the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until dissolved, and then 1.2 g of prepared tea saponin powder was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral, and the obtained filter cake was dried in an 80°C oven for 1 h to obtain bismuth oxychloride nanoflowers.

[0055] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers (40°C, no acetonitrile) includes the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (taken from the front and shaken well) was added as an oxidizing agent, the obtained mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 5 mL of acetonitrile was added for desulfurization reaction. The temperature of the desulfurization reaction was 40°C, the stirring rate was 1.0 kr / min, and the reaction time was 30 min. After sampling and detecting the concentration of sulfides, the catalyst performance of bismuth oxychloride nanoflowers was evaluated. Example 6

[0056] A method for preparing bismuth oxychloride nanoflowers induced by tea saponin includes the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until dissolved, and then 0.5 g of prepared tea saponin powder was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral, and the obtained filter cake was dried in an 80°C oven for 1 h to obtain bismuth oxychloride nanoflowers.

[0057] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers (40°C, 2.5 mL of acetonitrile), comprising the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (previously shaken well) was added as an oxidizing agent, the obtained mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 2.5 mL of acetonitrile was added for desulfurization reaction. The temperature of the desulfurization reaction was 40°C, the stirring rate was 1.0 kr / min, and the reaction time was 30 min. The sulfide concentration was detected after sampling to evaluate the catalyst performance of the bismuth oxychloride nanoflowers. Example 7

[0058] A method for preparing bismuth oxychloride nanoflowers induced by tea saponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until dissolved, and then 0.5 g of prepared tea saponin powder was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral, and the obtained filter cake was dried in an 80°C oven for 1 h to obtain bismuth oxychloride nanoflowers.

[0059] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers (40°C, 2.5 mL of acetonitrile), comprising the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (previously shaken well) was added as an oxidizing agent, the obtained mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 2.5 mL of acetonitrile was added for desulfurization reaction. The temperature of the desulfurization reaction was 40°C, the stirring rate was 1.0 kr / min, and the reaction time was 30 min. The sulfide concentration was detected after sampling to evaluate the catalyst performance of the bismuth oxychloride nanoflowers. Example 8

[0060] A method for preparing bismuth oxychloride nanoflowers induced by tea saponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, and after stirring and dissolving, 0.5 g of prepared tea saponin powder was added, and after stirring until completely dissolved, it was poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, and then filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral. The obtained filter cake was dried in an oven at 80°C for 1 h to obtain bismuth oxychloride nanoflowers.

[0061] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers (60°C, 5 mL of acetonitrile), comprising the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (previously shaken well) was added as an oxidizing agent, the resulting mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 5 mL of acetonitrile was added for desulfurization reaction. The desulfurization reaction temperature was 60°C, the stirring rate was 1.0 kr / min, and after 30 min of reaction, the sample was taken for detection of sulfide concentration to evaluate the catalyst performance of bismuth oxychloride nanoflowers. Example 9

[0062] A method for preparing bismuth oxychloride nanoflowers induced by tea saponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, and after stirring and dissolving, 0.5 g of prepared tea saponin powder was added, and after stirring until completely dissolved, it was poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, and then filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral. The obtained filter cake was dried in an oven at 80°C for 1 h to obtain bismuth oxychloride nanoflowers.

[0063] A method for oxidizing and desulfurizing bismuth oxychloride nanoflowers (60°C, 5 mL of acetonitrile), comprising the following steps: 0.05 g of bismuth oxychloride nanoflowers was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (previously shaken well) was added as an oxidizing agent, the resulting mixture was shaken well, then 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT) was added, and finally 5 mL of acetonitrile was added for desulfurization reaction. The desulfurization reaction temperature was 60°C, the stirring rate was 1.0 kr / min, and after 30 min of reaction, the sample was taken for detection of sulfide concentration to evaluate the catalyst performance of bismuth oxychloride nanoflowers.

[0064] Comparative Example 1 (no addition of tea saponin) A method for preparing bismuth oxychloride nanoflowers induced by tea saponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, and filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral. The obtained filter cake was dried in an 80°C oven for 1 h to obtain bismuth oxychloride nanospheres.

[0065] A method for bismuth oxychloride nanosphere oxidative desulfurization (40°C, 5 mL of acetonitrile), comprising the following steps: 0.05 g of bismuth oxychloride nanospheres was weighed into a two-port jacketed reaction bottle, then 0.5 mL of 5% mass fraction sodium hypochlorite solution (taken before being fully shaken) was added as an oxidizing agent, the obtained mixture was fully shaken, then 10 mL of simulated diesel containing 500 ppm of dibenzothiophene (DBT) was added, and finally 5 mL of acetonitrile was added for desulfurization reaction. The desulfurization reaction temperature was 40°C, the stirring rate was 1.0 kr / min, and the reaction time was 30 min. After sampling and detecting the sulfide concentration, the catalyst performance of bismuth oxychloride nanospheres was evaluated.

[0066] Comparative Example 2 (1.0 g of purchased tea saponin) A method for preparing bismuth oxychloride nanoflowers induced by tea saponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate was added to 70 mL of ethylene glycol and stirred until dissolved; then 0.35 g of sodium chloride was added, stirred until completely dissolved, and then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160°C for 12 h, cooled to room temperature, and filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral. The obtained filter cake was dried in an 80°C oven for 1 h to obtain bismuth oxychloride nanospheres.

[0067] A method for bismuth oxychloride oxidative desulfurization (40°C, 5 mL of acetonitrile), comprising the following steps: Take 0.05 g of bismuth oxychloride in a two-port jacketed reaction bottle, then add 0.5 mL of 5% mass fraction of sodium hypochlorite solution (take the front fully oscillated) as oxidant, the resulting mixture is fully oscillated, then add 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT), finally add 5 mL of acetonitrile, carry out desulfurization reaction, the temperature of desulfurization reaction is 40℃, the stirring rate is 1.0 kr / min, after 30 min of reaction time, take sample to detect sulfide concentration to evaluate the catalyst performance of bismuth oxychloride nanoflower.

[0068] Comparative Example 3 Compared with Example 1, the difference of Comparative Example 3 is only that 5 mL of 0.129 mg / mL tea saponin concentrate is used instead of 0.3 g of tea saponin powder in Example 1.

[0069] The preparation method of 0.129 mg / mL tea saponin concentrate is as follows: First, gradient extraction: tea meal powder (solid) and liquid (city supplied tap water) are mixed according to solid-liquid volume ratio of 1:4, after 80℃ water bath extraction for 60 min, filter while hot; the filter residue is added with water twice, both with solid-liquid ratio of 1:2, the first time of gradient water extraction is 30 min, and the second time of gradient water extraction is 20 min, and the three times of filtrate are combined to obtain 180 mL (pH about 6-6.5) of filtrate; Secondly, flocculation and impurity removal, activated carbon decolorization: 2.5 g of Al2(SO4)3·18H2O solid is added to the filtrate, boiled and stirred for 5 min, naturally settled for 2 h, then centrifuged at 5000 r / min for 3 min, about 150 mL of supernatant is taken, 1.5% of activated carbon (wrapped with gauze) of the mass of the supernatant is added and heated and stirred, after 5 min, the activated carbon is removed, and the decolorized supernatant is obtained, heated and concentrated to obtain 0.129 mg / mL tea saponin concentrate.

[0070] Comparative Example 4 (without adding tea saponin) A method for preparing bismuth oxychloride nanoflower induced by tea saponin, comprising the following steps: At room temperature, 2.9 g of bismuth nitrate pentahydrate is added to 70 mL of ethylene glycol, and stirred until dissolved; then 0.35 g of sodium chloride is added, stirred until completely dissolved, then poured into a polytetrafluoroethylene liner, locked into a reaction kettle, heated at 160℃ for 12 h, cooled to room temperature, filtered and washed with 200 mL of deionized water and 150 mL of ethanol in sequence until neutral, the obtained filter cake is dried in an 80℃ oven for 1 h to obtain bismuth oxychloride.

[0071] A method for bismuth oxychloride oxidation desulfurization (40℃, 2.5 mL of acetonitrile), comprising the following steps: Take 0.05 g of bismuth oxychloride in a two-port jacketed reaction bottle, then add 0.5 mL of 5% mass fraction of sodium hypochlorite solution (take the front fully oscillated) as an oxidizing agent, the resulting mixture is fully oscillated, then add 10 mL of simulated diesel oil containing 500 ppm of dibenzothiophene (DBT), finally add 2.5 mL of acetonitrile, and carry out the desulfurization reaction, the desulfurization reaction temperature is 40℃, the stirring rate is 1.0 kr / min, and the sample is taken for detection after 30 min of reaction time to evaluate the catalyst performance of the bismuth oxychloride nanoflower.

[0072] Product effect test 1. Structure characterization Figure 1 The scanning electron microscope (SEM) image of the bismuth oxychloride nanoflower prepared in Example 2 of the application.

[0073] Figure 2 The scanning electron microscope (SEM) image of the bismuth oxychloride nanoflower prepared in Example 3 of the application.

[0074] Figure 3 The scanning electron microscope (SEM) image of the bismuth oxychloride nanosphere prepared in Comparative Example 1 of the application.

[0075] Figure 4 The scanning electron microscope (SEM) image of the bismuth oxychloride nanoflower prepared in Comparative Example 2 of the application.

[0076] Figure 5 The Fourier transform infrared spectroscopy (FTIR) spectrum of the bismuth oxychloride nanoflower prepared in Examples 2-3 of the application, the bismuth oxychloride nanosphere prepared in Comparative Example 1, and the bismuth oxychloride nanoflower prepared in Comparative Example 2; wherein "Transmittance" represents the transmittance, and "Wavenumber" represents the wave number. From Figure 5 It can be seen that there are O-H and Bi-O bond characteristic absorption peaks in the examples and comparative examples, indicating that they all contain these groups; but in the infrared spectrum of the example, there are absorption peaks at 1256 cm -1 , 1114 cm -1 , and 918 cm -1 , which belong to the characteristic peaks of C-O bond, indicating that tea saponin was added to induce the reaction in the preparation process, and C-O group was introduced into BiOCl.

[0077] Figure 6 The thermogravimetric analysis (TGA) graph of the bismuth oxychloride nanoflower prepared in Examples 2-3 of the application, the bismuth oxychloride nanosphere prepared in Comparative Example 1, and the bismuth oxychloride nanoflower prepared in Comparative Example 2; wherein "TG" represents the trajectory of sample mass change with temperature, and "temperature" represents the temperature. From Figure 6It can be seen that the weight loss ratio of the embodiment is about 25-30%, while the weight loss ratio of the comparative example is about 15-20%. This shows that the embodiment contains more organic matters which are easy to decompose and lose at high temperature. These organic matters are generated during the preparation process of reacting tea saponin with BiOCl.

[0078] Figure 7 The specific surface area (BET) and pore size analysis diagram of the BiOCl nanoflower prepared in Example 2 of the present application; wherein “Quantity adsorbed” represents the adsorption amount, “Relative pressure” represents the relative pressure, “dV / dlogD” represents the pore volume increment corresponding to the unit logarithmic pore size change, “Pore diameter” represents the pore size, “Adsorption” represents adsorption, and “Desorption” represents desorption.

[0079] Figure 8 The specific surface area (BET) and pore size analysis diagram of the BiOCl nanoflower prepared in Example 3 of the present application; wherein “Quantity adsorbed” represents the adsorption amount, “Relative pressure” represents the relative pressure, “dV / dlogD” represents the pore volume increment corresponding to the unit logarithmic pore size change, “Pore diameter” represents the pore size, “Adsorption” represents adsorption, and “Desorption” represents desorption.

[0080] Figure 9 The specific surface area (BET) and pore size analysis diagram of the BiOCl nanosphere prepared in Comparative Example 1; wherein “Quantity adsorbed” represents the adsorption amount, “Relative pressure” represents the relative pressure, “dV / dlogD” represents the pore volume increment corresponding to the unit logarithmic pore size change, “Pore diameter” represents the pore size, “Adsorption” represents adsorption, and “Desorption” represents desorption.

[0081] Figure 10 The specific surface area (BET) and pore size analysis diagram of the BiOCl nanosphere prepared in Comparative Example 2; wherein “Quantity adsorbed” represents the adsorption amount, “Relative pressure” represents the relative pressure, “dV / dlogD” represents the pore volume increment corresponding to the unit logarithmic pore size change, “Pore diameter” represents the pore size, “Adsorption” represents adsorption, and “Desorption” represents desorption.

[0082] The specific surface area (BET) and pore size of the BiOCl nanoflowers or BiOCl nanospheres of Examples 2-3 and Comparative Examples 1-2 were tested by Brunauer-Emmett-Teller (BET) method, using high-purity nitrogen as adsorbate, static volumetric method to measure the adsorption isotherm at 77.3K liquid nitrogen temperature, and the results are shown in Table 1.

[0083] Table 1: Specific surface area and pore size results of examples and comparative examples S BET (m 2 ·g -1 )]]> Pore volume (cm 3 ·g -1 )]]> Average pore diameter (nm) Example 2 34.51 0.11 12.99 Example 3 28.16 0.085 12.10 Comparative Example 1 16.92 0.049 11.46 Comparative Example 2 21.87 0.060 11.00 From Figure 7 to Figure 10 , and Table 1, it can be seen that the specific surface area of Examples 2 and 3 is increased compared with the comparative examples, and the increase in specific surface area is beneficial to the catalyst to provide more active sites, thereby improving the activity of catalytic desulfurization; at the same time, the average pore size is also slightly increased compared with the comparative examples, which is beneficial to the entry of sulfide molecules into the pore for catalytic reaction, thereby improving the desulfurization rate.

[0084] Figure 12 XRD patterns of BiOCl prepared under different conditions; wherein "Intensity" represents intensity, and "2θ (degree)" represents diffraction angle (degree).

[0085] Figure 13 XRD patterns of self-made tea saponin and purchased tea saponin. The purchased tea saponin is from Zhejiang Bodan Heng Food Ingredients Co., Ltd., from Figure 13 It can be seen that the self-made tea saponin has obvious XRD diffraction peaks, indicating that it has a regular crystal structure, while the purchased tea saponin has only one scattering peak, indicating that it does not have a crystal structure.

[0086] 2. Desulfurization effect The desulfurization catalytic performance of the BiOCl nanoflowers (as catalyst) of the examples and comparative examples is shown in Table 1 and Figure 11 The catalyst turnover frequency (TOF) in Table 1 is an index used to characterize the catalytic rate according to the active sites, and its calculation formula is as follows: .

[0087] The calculation formula of the desulfurization rate is as follows: The desulfurization rate (X%) of the reaction can be calculated from the sulfide concentration (S t ) in the oil phase after reaction time t and the initial sulfide concentration (S0) in the oil phase, as shown in formula (1). In order to eliminate the error introduced by the micro-injector, the internal standard method is used to detect the sulfide concentration, so the desulfurization rate (X%) can be calculated from the sulfide peak area (A St ) in the oil phase after reaction time t and the internal standard (tetradecane) peak area (A Ct ), and the corresponding initial sulfide peak area (AS0 ) and the initial peak area (A C0 ) calculated as shown in equation (2).

[0088] (1) (2) Table 2: Desulfurization effect of examples and comparative examples Temperature (°C) Catalyst amount (g) Sodium hypochlorite amount (mL) Acetonitrile amount (mL) Reaction time 1 (min) Desulfurization rate 1 (%) Catalyst turnover frequency 1 (TOF*10^1) Reaction time 2 (min) Desulfurization rate 2 (%) Catalyst turnover frequency 2 (TOF*10^1) Example 1 40 0.05 0.5 5 10 32.2 1.56 60 84.4 4.09 Example 2 40 0.05 0.5 5 10 99.9 4.84 60 99.9 4.84 Example 3 40 0.05 0.5 5 10 99.9 4.84 60 99.9 4.84 Example 4 40 0.05 0.5 5 10 99.9 4.84 60 99.9 4.84 Example 5 40 0.05 0.5 0 10 7.9 0.38 60 19.2 0.93 Example 6 40 0.05 0.5 2.5 10 97.8 4.74 60 97.7 4.73 Example 7 40 0.05 0.5 2.5 10 98.2 4.76 60 97.8 4.74 Example 8 60 0.05 0.5 5 10 37.6 1.82 60 48.5 2.35 Example 9 60 0.05 0.5 5 10 99.6 4.82 60 99.3 4.81 Comparative Example 1 40 0.05 0.5 5 10 31.2 1.51 60 34.8 1.69 Comparative Example 2 40 0.05 0.5 5 10 31.7 1.54 60 90.5 4.39 Comparative Example 3 40 0.05 0.5 5 10 29.8 1.45 60 35.3 1.71 Comparative Example 4 40 0.05 0.5 2.5 10 18.3 0.88 60 19.8 0.96 From Table 2 and Figure 11 It can be seen that the bismuth oxychloride nanoflower prepared in the examples of the present application has obvious advantages in desulfurization compared with the comparative examples.

Claims

1. A method for preparing bismuth oxychloride nanoflowers induced by tea saponin, characterized in that, Includes the following steps: Bismuth source, chlorine source, and solvent were mixed, then tea saponin was added, mixed, heated to react, and separated to obtain the bismuth oxychloride nanoflowers. The preparation method of the tea saponin includes the following steps: (1) Mix tea seed powder with water, perform water bath extraction, filter to obtain first filtrate and filter residue a, mix filter residue a with water for extraction, filter to obtain second filtrate and filter residue b, mix filter residue b with water for extraction, filter to obtain third filtrate and filter residue c, combine first filtrate, second filtrate and third filtrate to obtain filtrate; (2) Take the filtrate from step (1) and mix it with aluminum sulfate or aluminum sulfate hydrate, boil, settle, centrifuge, and obtain the supernatant. Then add activated carbon to decolorize and obtain the decolorized supernatant. (3) Take the decolorized supernatant from step (2), boil and concentrate it, cool it and add anhydrous ethanol to obtain a trans-extract containing flocculent precipitate; (4) The extract containing flocculent precipitate obtained in step (3) is concentrated and dried to obtain the tea saponin.

2. The method according to claim 1, characterized in that, In step (1), the solid-liquid volume ratio of the tea seed powder to water is 1:(3-4); and / or, the water bath extraction temperature is 80-85℃ and the time is 50-60 minutes; and / or, during the extraction of filter residue a with water, the volume ratio of filter residue a to water is 1:(2-3) and the extraction time is 20-30 minutes; and / or, during the extraction of filter residue b with water, the volume ratio of filter residue b to water is 1:(2-3) and the extraction time is 20-30 minutes; and / or, the pH of the filtrate is 6-6.

5.

3. The method according to claim 1, characterized in that, In step (2), the aluminum sulfate hydrate is aluminum sulfate octadecahydrate; and / or, the ratio of the filtrate from step (1) to aluminum sulfate or aluminum sulfate hydrate is (170-180) mL: (2-2.5) g; and / or, the boiling time is 3-5 minutes; and / or, the centrifugation speed is 4000-6000 r / min and the centrifugation time is 1-5 minutes; and / or, the sedimentation time is 1-2 hours; and / or, the mass of activated carbon is 1-2% of the mass of the supernatant.

4. The method according to claim 1, characterized in that, In step (4), the drying is carried out at 40-60°C for 3-5 hours.

5. The method according to claim 1, characterized in that, The bismuth source includes bismuth nitrate or bismuth nitrate hydrate; and / or, the chlorine source includes sodium chloride or potassium chloride; and / or, the mass ratio of the bismuth source to the chlorine source is 2.5-3.5:(0.3-0.4).

6. The method according to claim 1, characterized in that, The solvent includes ethylene glycol; and / or the heating reaction is carried out at a temperature of 140-180°C for 8-12 hours.

7. The method according to claim 1, characterized in that, The separation process includes filtration, washing, and drying.

8. A bismuth oxychloride nanoflower, characterized in that, Prepared by the method described in any one of claims 1-7.

9. The application of bismuth oxychloride nanoflowers prepared by the method according to any one of claims 1-7 in the field of desulfurization.

10. A method for oxidative desulfurization of bismuth oxychloride nanoflowers, characterized in that, Includes the following steps: Bismuth oxychloride nanoflowers were mixed with an oxidant, and then diesel fuel and acetonitrile were added to carry out a desulfurization reaction.

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