阅读说明：本技术 一种用于油田废水处理的Bi4O5Br2/BiOBr复合光催化剂的制备方法 (preparation method of Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment ) 是由 张旭 杨萍 刘卫华 焦国盈 杨博 张瀛 王均 王�琦 丁忠佩 庞进 谭洪超 陈 于 2019-09-23 设计创作，主要内容包括：本发明公开了一种用于油田废水处理的Bi_4O_5Br_2/BiOBr复合光催化剂的制备方法,具体是：按照摩尔比Bi:Br＝1:1.75的比例,将含溴化合物的丙三醇溶液逐滴滴加入含铋化合物的丙三醇溶液中,搅拌均匀,升温至140～180℃,恒温反应14～18h,得到前驱物；然后向前驱物中加入蒸馏水,40～70℃水浴条件下,水解反应21～26h,得到Bi_4O_5Br_2/BiOBr复合光催化剂。所述含溴化合物为溴化钾。所述含铋化合物是五水硝酸铋。该催化剂的制备方法降低了生产成本,简化了生产工艺。所制备的复合催化剂对可见光响应增强,特别是在去除油田中苯酚和双酚废水具有很高活性,可用于可见光条件下催化降解油田中的苯酚和双酚废水。该催化剂相比较现有Bi_4O_5Br_2、BiOBr光催化剂具有更好的性能。(The invention discloses a preparation method of a Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment, which comprises the following steps: dropwise adding a glycerol solution containing a bromine compound into a glycerol solution containing a bismuth compound according to the molar ratio of Bi to Br of 1 to 1.75, uniformly stirring, heating to 140-180 ℃, and reacting at a constant temperature for 14-18 h to obtain a precursor; and then adding distilled water into the precursor, and carrying out hydrolysis reaction for 21-26 h under the water bath condition of 40-70 ℃ to obtain the Bi4O5Br2/BiOBr composite photocatalyst. The bromine-containing compound is potassium bromide. The bismuth-containing compound is bismuth nitrate pentahydrate. The preparation method of the catalyst reduces the production cost and simplifies the production process. The prepared composite catalyst has enhanced response to visible light, has high activity particularly in removing phenol and bisphenol wastewater in oil fields, and can be used for catalyzing and degrading phenol and bisphenol wastewater in oil fields under the condition of visible light. Compared with the existing Bi4O5Br2 and BiOBr photocatalysts, the catalyst has better performance.)

1. a preparation method of a Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment is characterized in that a glycerol solution containing a bromine compound is dropwise added into a glycerol solution containing a bismuth compound according to the molar ratio of Bi elements to Br elements, namely Bi: Br is 1:1.75, the temperature is raised to 140-180 ℃, and a constant-temperature reaction is carried out for 14-18 hours to obtain a precursor; and then adding distilled water into the precursor, and carrying out hydrolysis reaction for 21-26 h under the water bath condition of 40-70 ℃ to obtain the Bi4O5Br2/BiOBr composite photocatalyst.

2. The preparation method of the Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment according to claim 1, comprising the following steps:

(1) weighing a bismuth-containing compound and a bromine-containing compound according to the molar ratio of Bi to Br of 1: 1.75; dissolving a bismuth-containing compound in glycerol; dissolving the bromine-containing compound in another portion of glycerol;

(2) dropwise adding a glycerol solution containing a bromine compound into a glycerol solution containing a bismuth compound, uniformly stirring, heating to 140-180 ℃, reacting at a constant temperature for 14-18 h, and drying the generated precipitate at 60-80 ℃ to obtain a precursor;

(3) Adding distilled water into the precursor, carrying out hydrolysis reaction for 21-26 h under the water bath condition of 40-70 ℃, and drying the hydrolysate for 6-24 h at 60-80 ℃ to obtain the Bi4O5Br2/BiOBr composite photocatalyst.

3. The preparation method of the Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment according to claim 2, wherein in the step (2), the temperature is raised to 160 ℃, and the isothermal reaction is carried out for 16 hours.

4. the preparation method of the Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment, as claimed in claim 2, wherein in the step (3), the ratio of the mass of the precursor to the volume of the distilled water is 0.3-0.6 g: 40-70 mL.

5. the preparation method of the Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment, according to claim 4, wherein in the step (3), the hydrolysis reaction is carried out for 24 hours in a water bath at 50 ℃.

6. The preparation method of the Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment according to claim 2, wherein the bromine-containing compound is potassium bromide or sodium bromide.

7. The method for preparing the Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment according to claim 2, wherein the bismuth-containing compound is bismuth nitrate pentahydrate.

8. The preparation method of the Bi4O5Br2/BiOBr composite photocatalyst for oilfield wastewater treatment according to any one of claims 1 to 7, wherein the prepared Bi4O5Br2/BiOBr composite photocatalyst is used for catalytic degradation of phenol and bisphenol wastewater in an oilfield under visible light conditions.

Technical Field

The invention relates to the technical field of photocatalysis, in particular to a preparation method of a Bi4O5Br2/BiOBr composite photocatalyst for catalytically degrading phenol and bisphenol wastewater in an oil field under the condition of visible light.

Background

Petroleum is a strategic material which is very important in the world at present, and promotes the vigorous development of the economy of China. Meanwhile, the oil extraction process also brings some technical problems, such as a series of oil field wastewater generated in oil extraction. The oil field waste water has complex components, the main components of the oil field waste water comprise water, crude oil, soluble gas, suspended matters and various chemical additives, and the oil field waste water has the characteristics of high viscosity, high turbidity, high stability and the like. If the waste water is directly discharged, the underground environment and the natural environment can cause serious pollution, which runs counter to the green technology implemented in China. The method for treating the oil field wastewater generally adopts physical methods, pressure sedimentation methods, filtration separation methods and chemical methods. Among these methods, the photocatalytic oxidation method is an advanced oxidation chemical method, which is an environment-friendly treatment technology, and has mild reaction conditions, strong oxidation capacity and wide application range, and the method for treating refractory organic pollutants has become a research hotspot at home and abroad. At present, the development of oil field industry in China is inhibited by phenolic organic pollutant wastewater generated by oil refining, so that the problem of green and friendly treatment of phenolic wastewater is an imminent solution for oil field exploitation.

the photocatalysis technology means that the semiconductor photocatalyst can directly utilize solar energy to convert the light energy into chemical energy to promote the degradation of compounds. The action mechanism is that active oxygen species with extremely strong activity are generated under the action of light of a semiconductor catalyst, and the active oxygen species can almost non-selectively oxidize and degrade organic pollutants in the phenolic wastewater into non-toxic or low-toxic micromolecule substances and even directly mineralize the micromolecule substances into carbon dioxide, water and other micromolecule carboxylic acids, so that the aim of harmlessness is fulfilled. The technology has the advantages of no selectivity, strong oxidation capability, high reaction speed, high treatment efficiency, no secondary pollution and the like. The photocatalyst plays an important role in photocatalysis, and the development of a novel photocatalyst is a core technology for improving the photocatalytic efficiency.

Bismuth oxyhalide is a novel semiconductor material, and has the characteristics of no toxicity, low price, strong oxidation-reduction capability, stable chemical property, light corrosion resistance and the like, and is favored by people. However, the bottom position of the conduction band of bismuth oxyhalide is too positive to effectively activate more molecular oxygen, thereby failing to effectively improve the photocatalytic efficiency. The position of a conduction band is changed by controlling the values of halogen atoms and oxygen atoms in bismuth oxyhalide, so that a bismuth-rich strategy is started to regulate and control the position of the conduction band in the energy band, and the novel bismuth-rich photocatalyst is obtained. The combination of the advantages of bismuth oxyhalide and bismuth-rich bismuth oxyhalide has led to the development of the eye of researchers.

li et al synthesized Bi4O5Br2/BiOBr composite catalyst by chemical precipitation method in 2016, and it has stronger activity to degrade resorcinol than monomer Bi4O5Br2 and BiOBr under visible light irradiation. Su in 2018 synthesizes a Bi4O5Br2/BiOBr complex catalyst by a one-step hydrothermal method, and the degradation ciprofloxacin has stronger activity than that of monomers Bi4O5Br2 and BiOBr. The preparation of Bi4O5Br2/BiOBr complexes reported in these documents. However, it is a hot spot of our research to explore other simple and efficient preparation methods.

Disclosure of Invention

the invention aims to provide a simple and efficient preparation method of a Bi4O5Br2/BiOBr composite catalyst for treating oil field wastewater.

The preparation method of the Bi4O5Br2/BiOBr composite catalyst provided by the invention comprises the following specific steps:

(1) weighing a bismuth-containing compound and a bromine-containing compound according to the molar ratio of Bi to Br of 1 to 1.75; dissolving a bismuth-containing compound in glycerol; dissolving the bromine-containing compound in another portion of glycerol;

(2) Dropwise adding a glycerol solution containing a bromine compound into a glycerol solution containing a bismuth compound, uniformly stirring, heating to 140-180 ℃, reacting at a constant temperature for 14-18 h, and drying the generated precipitate at 60-80 ℃ to obtain a precursor;

(3) Adding distilled water into the precursor, carrying out hydrolysis reaction for 21-26 h under the water bath condition of 40-70 ℃, and drying the hydrolysate for 6-24 h at 60-80 ℃ to obtain the Bi4O5Br2/BiOBr composite photocatalyst. The photocatalyst is a bismuth-rich bismuth oxyhalide and bismuth oxyhalide composite photocatalyst.

Preferably, the bromine-containing compound is preferably potassium bromide or sodium bromide. The bismuth-containing compound is preferably bismuth nitrate pentahydrate.

A preferred preparation method is as follows:

(1) dissolving 4mmol of bismuth-containing compound in 20-60 mL of glycerol; dissolving 7mmol of bromine-containing compound in another part of 20-60 mL of glycerol;

(2) Dropwise adding a glycerol solution containing a bromine compound into a glycerol solution containing a bismuth compound, uniformly stirring, heating to 140-180 ℃, reacting at a constant temperature for 14-18 h, and drying the generated precipitate at 60-80 ℃ for 5-24 h to obtain a precursor;

(3) Adding 40-70 mL of distilled water into 0.3-0.6 g of precursor, carrying out hydrolysis reaction for 21-26 h under the water bath condition of 40-70 ℃, and drying the hydrolysate for 6-24 h at 60-80 ℃ to obtain the Bi4O5Br2/BiOBr composite photocatalyst

Preferably, in the step (2), the temperature is raised to 160 ℃, and the reaction is carried out for 16 hours at constant temperature.

Preferably, in the step (3), the hydrolysis reaction is carried out for 24 hours under the condition of water bath at 50 ℃.

The Bi4O5Br2/BiOBr composite photocatalyst prepared by the method is used for catalyzing and degrading phenol and bisphenol wastewater in an oil field under the condition of visible light.

Compared with the prior art, the invention has the advantages that:

Firstly, the invention adopts nontoxic raw material components, and prepares the Bi4O5Br2/BiOBr composite photocatalyst by accurately controlling the molar ratio of Bi element to Br element in the reaction raw materials, namely the ratio of Bi to Br being 1 to 1.75 and adopting an extremely simple process method, which is the initiative of the inventor.

Secondly, the catalytic activity of the Bi4O5Br2/BiOBr composite photocatalyst prepared by the invention is superior to that of Bi4O5Br2 and BiOBr monomers. The specific surface area of the Bi4O5Br2/BiOBr catalyst is 42.88m2g-1, the specific surface area of the Bi4O5Br2 catalyst is 64.30m2g-1, the specific surface area of the BiOBr catalyst is 21.34m2g-1, and the increase of the specific surface area improves the catalytic activity of the catalyst. The prepared photocatalyst can excite more photoproduction electrons under visible light, the electron-hole recombination rate is reduced, the photocatalytic activity is obviously improved, particularly, the oxidized phenol wastewater has high activity, the preparation method is simple, the condition is mild, the purposes of reducing the cost and simplifying the production flow are achieved, and the photocatalyst can be applied to the oxidation of the oil field phenol wastewater.

Thirdly, under the irradiation of visible light with the wavelength of more than 420nm, the removal rates of Bi4O5Br2, Bi4O5Br2/BiOBr and BiOBr of the original 20mg/L phenol solution are respectively 67.29%, 83.21% and 58.38% in 5h, and the removal rates of Bi4O5Br2, Bi4O5Br2/BiOBr and BiOBr of the original 10mg/L bisphenol A solution are respectively 59.97%, 76.45% and 48.78% in 5h, so that the photocatalytic performance is greatly improved.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

XRD test patterns of the precursors of figure 1, example 1, comparative example 1 and comparative example 2 are carried out.

Fig. 2 shows XRD test patterns of the prepared products of example 1, comparative example 1 and comparative example 2.

FIG. 3 shows BET spectra of Bi4O5Br2/BiOBr composite photocatalyst and monomer photocatalyst Bi4O5Br2, BiOBr of example 1.

FIG. 4 is a graph showing the degradation efficiency of oxidized phenols of the Bi4O5Br2/BiOBr composite photocatalyst and the monomer photocatalysts Bi4O5Br2 and BiOBr in example 1.

FIG. 5 is a graph showing the degradation efficiency of oxidized bisphenol A wastewater of Bi4O5Br2/BiOBr composite photocatalyst and monomer photocatalyst Bi4O5Br2 and BiOBr in example 1.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.