阅读说明：本技术 一种用于处理油田废液的Ag-Bi固溶体复合光催化剂的制备方法 (Preparation method of Ag-Bi solid solution composite photocatalyst for treating oil field waste liquid ) 是由 张旭 杨萍 刘卫华 张瀛 王均 焦国盈 梁兵 杨博 于希南 吴俊霖 侯昆朋 张 于 2019-09-25 设计创作，主要内容包括：本发明公开了一种用于处理油田废液的Ag-Bi固溶体复合光催化剂的制备方法,步骤如下：S1、将含铋化合物溶于乙二醇中,得溶液A；将含溴化合物和含氯化合物溶于另一份乙二醇中,得溶液B；S2、将溶液B逐滴加入到溶液A中,混合均匀,然后将混合液升温至140～180℃,恒温反应14～18h,得到BiOCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>；S3、将BiOCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>溶于蒸馏水中,然后加入含银化合物,得到溶液C；S4、另取含氯化合物和含溴化合物溶于蒸馏水中,得到溶液D,将溶液D加入溶液C中,避光搅拌1～3h,离心,干燥,得到AgCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>/BiOCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>；S5、将AgCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>/BiOCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>溶于蒸馏水中,在全波长氙灯下照射0.5-2h,得到Ag-AgCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>/BiOCl<Sub>0.5</Sub>Br<Sub>0.5</Sub>复合光催化剂。本发明的催化剂对可见光响应增强,特别是在光催化降解丙烯酰胺具有很高活性,可应用于油田中丙烯酰胺的去除。(The invention discloses a preparation method of an Ag-Bi solid solution composite photocatalyst for treating oil field waste liquid, which comprises the following steps: s1, dissolving the bismuth-containing compound in ethylene glycol to obtain a solution A; dissolving a bromine-containing compound and a chlorine-containing compound in the other part of ethylene glycol to obtain a solution B; s2, dropwise adding the solution B into the solution A, uniformly mixing, heating the mixed solution to 140-180 ℃, and reacting at constant temperature for 14-18 h to obtain BiOCl 0.5 Br 0.5 (ii) a S3, adding BiOCl 0.5 Br 0.5 Dissolving in distilled water, and adding silver-containing compound to obtainSolution C; s4, dissolving another chlorine-containing compound and a bromine-containing compound in distilled water to obtain a solution D, adding the solution D into the solution C, stirring for 1-3 h in the dark, centrifuging, and drying to obtain AgCl 0.5 Br 0.5 /BiOCl 0.5 Br 0.5 (ii) a S5, adding AgCl 0.5 Br 0.5 /BiOCl 0.5 Br 0.5 Dissolving in distilled water, and irradiating under full-wavelength xenon lamp for 0.5-2 hr to obtain Ag-AgCl 0.5 Br 0.5 /BiOCl 0.5 Br 0.5 A composite photocatalyst is provided. The catalyst disclosed by the invention has enhanced response to visible light, particularly has high activity in photocatalytic degradation of acrylamide, and can be applied to removal of acrylamide in oil fields.)

1. A preparation method of an Ag-Bi solid solution composite photocatalyst for treating oil field waste liquid is characterized by comprising the following steps:

s1, dissolving the bismuth-containing compound in ethylene glycol to obtain a solution A; dissolving a bromine-containing compound and a chlorine-containing compound which are equal in molar weight to the bismuth-containing compound in another part of ethylene glycol to obtain a solution B;

s2, dropwise adding the solution B into the solution A, uniformly mixing, and then heating the mixed solution to 140EReacting at 180 ℃ for 14-18 h at constant temperature to obtain BiOCl_0.5Br_0.5；

S3, adding BiOCl_0.5Br_0.5Dissolving the mixture in distilled water, adding a silver-containing compound, stirring at normal temperature for 20-100 min, and stirring BiOCl_0.5Br_0.5The molar ratio of the silver-containing compound to the silver-containing compound is 2:1, so as to obtain a solution C;

s4, dissolving another chlorine-containing compound and a bromine-containing compound in distilled water to obtain a solution D, wherein the molar ratio of the chlorine-containing compound to the silver-containing compound is 1:1, and the molar ratio of the bromine-containing compound to the silver-containing compound is 0.5:1, adding the solution D into the solution C, stirring for 1-3 h in a dark place, centrifuging, and drying to obtain AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5；

S5, adding AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5Dissolving in distilled water, irradiating under full-wavelength xenon lamp for 0.5-2 hr, centrifuging, and drying to obtain Ag-AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5A composite photocatalyst is provided.

2. The preparation method of the Ag-Bi solid solution composite photocatalyst for treating the oilfield waste liquid as claimed in claim 1, wherein in the solution A, the concentration of the bismuth-containing compound is 0.07-0.2 mol/L; in the solution B, the concentrations of the bromine-containing compound and the chlorine-containing compound are the same, and the value range is 0.08-0.2 mol/L.

3. The method for preparing the Ag-Bi solid solution composite photocatalyst for treating the oilfield waste liquid according to claim 2, wherein the bismuth-containing compound is bismuth nitrate pentahydrate; the bromine-containing compound is potassium bromide or sodium bromide; the chlorine-containing compound is potassium chloride or sodium chloride.

4. The method for preparing the Ag-Bi solid solution composite photocatalyst for treating the oilfield waste liquid according to claim 1, wherein the step S2 is specifically as follows: dropwise adding the solution B into the solution A, stirring for 20-100 min, heating the mixed solution to 160 ℃, reacting at constant temperature for 16h, washing the product with absolute ethyl alcohol, and reacting at 6 DEGDrying for 5-24 h at 0-80 ℃ to obtain BiOCl_0.5Br_0.5。

5. The method for preparing the Ag-Bi solid solution composite photocatalyst for treating the oilfield waste liquid as claimed in claim 4, wherein the step S3 is specifically as follows: adding BiOCl_0.5Br_0.5Adding into distilled water, stirring for 30min to dissolve completely, adding silver-containing compound, stirring at room temperature for 60min, and adding BiOCl_0.5Br_0.5The molar ratio of the silver-containing compound to the silver-containing compound is 2:1, so as to obtain a solution C; in solution C, BiOCl_0.5Br_0.5The concentration is 0.04-0.1mol/L, and the concentration of the silver-containing compound is 0.02-0.05 mol/L.

6. The method for preparing the Ag-Bi solid solution composite photocatalyst for treating the oilfield waste liquid as claimed in claim 5, wherein in the step S4, the concentration of the chlorine-containing compound in the solution D is 0.02-0.05 mol/L; the concentration of the bromine-containing compound is 0.01 to 0.025 mol/L; the drying temperature is 50-70 ℃, and the drying time is 8-16 h.

7. The method for preparing the Ag-Bi solid solution composite photocatalyst for treating the oilfield waste liquid according to claim 1, wherein the step S5 is specifically as follows: 0.2-0.5 g of AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5Dissolving the mixture in 20-50 mL of distilled water, irradiating for 0.5-2h under a full-wavelength xenon lamp, centrifuging, and drying for 8-16 h at 50-70 ℃ to obtain Ag-AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5A composite photocatalyst is provided.

8. A method for preparing a composite photocatalyst as claimed in any one of claims 1 to 7, wherein the Ag-AgCl is prepared_0.5Br_0.5/BiOCl_0.5Br_0.5The composite photocatalyst is used for catalyzing, oxidizing and fracturing acrylamide in the flowback fluid under visible light.

Technical Field

The invention relates to the technical field of photocatalysis, in particular to a catalyst for photocatalytic oxidation in fracturing flowback fluidVisible light responsive Ag-AgCl of enamides_0.5Br_0.5/BiOCl_0.5Br_0.5A preparation method of a composite photocatalyst.

Background

In the production process of an oil field, the problem of water logging is often caused due to the heterogeneity of a bottom layer, and water plugging is needed, namely the seepage state of water in a stratum is changed, so that the aims of reducing the water production of the oil field, maintaining the energy of the stratum and improving the final recovery ratio of the oil field are fulfilled. The acrylamide chemical water shutoff agent has selectivity of permeability to oil and water, and the permeability to oil can be reduced by more than 10% at most, and the permeability to water can be reduced by more than 90%. The technical problem is also brought by the treatment fluid discharged from the oil field while the benefit of the oil field is improved. The fracturing flow-back fluid has complex components, contains various organic additives, and has the characteristics of high COD value, high viscosity, high turbidity, high stability and the like. If the fracturing flow-back fluid is directly discharged or reinjected into the stratum, serious pollution is caused to the underground environment and the natural environment, which is contrary to the green technology implemented in China. In order to meet the requirement of green economy, an environment-friendly technology for treating fracturing flow-back fluid is a core technology for continuous exploitation of oil fields.

The photocatalytic oxidation method is an advanced oxidation chemical method, is an environment-friendly treatment technology, and means that a semiconductor photocatalyst can directly utilize solar energy to convert the light energy into chemical energy to promote the degradation of a compound. 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 which are difficult to degrade in the return liquid into non-toxic or low-toxic micromolecule substances and even directly mineralize carbon dioxide, water and other micromolecule carboxylic acids to achieve the harmless purpose. The technology has the advantages of no selectivity, strong oxidation capability, high reaction speed, high treatment efficiency, no secondary pollution and the like. The unique advantages of the photocatalysis technology enable the photocatalysis technology to have huge application prospects in treating fracturing flowback fluid of shale gas, the photocatalyst is the key of the photocatalysis technology, and the development of a novel photocatalyst is the core technology of the photocatalysis technology.

With the development of photocatalytic technology, a series of novel photocatalysts such as bismuth-based, silver-based, phosphorus-based and the like are reported, following the most classical titanium dioxide catalyst. In the development of catalysts, solid solution catalysts are the eye of researchers. Solid solutions refer to materials that are like crystals that produce a homogeneous, compositionally variable, like solution. Solid solution is an effective method for changing the electronic structure and energy band structure of semiconductors, and is formed by two semiconductors with similar radiuses, the same crystal structure and different wide forbidden bands and narrow forbidden bands. When the two substances form a solid solution, the structure of the semiconductor material is not changed, but the electronic structure of the semiconductor is changed due to the change of the constituent elements. Bismuth oxyhalide is a novel bismuth-based semiconductor material and has the characteristics of no toxicity, low price, strong oxidation-reduction capability, stable chemical property, light corrosion resistance and the like. The silver halide-based photocatalyst is also a novel semiconductor material, the activity of the silver halide-based photocatalyst is high, and the simple substance silver has a high-efficiency plasma effect. Based on the advantages of bismuth oxyhalide-based and silver halide-based photocatalysts, halogen atoms in the two photocatalysts meet the condition of forming a solid solution, so that a series of solid solution bismuth oxyhalide catalysts and solid solution silver halide catalysts are developed. The bismuth oxyhalide solid solution catalyst and the silver halide solid solution catalyst reported in the prior literature have stronger performance than the monomer, but the bismuth oxyhalide solid solution catalyst and the silver halide solid solution catalyst have not ideal utilization of solar energy, and the catalytic performance needs to be improved, so that further modification research on the bismuth oxyhalide solid solution catalyst and the silver halide solid solution catalyst is needed.

Disclosure of Invention

The invention aims to provide an Ag-Bi solid solution composite photocatalyst Ag-AgCl for treating oil field waste liquid_0.5Br_0.5/BiOCl_0.5Br_0.5The preparation method of (1).

The Ag-AgCl provided by the invention_0.5Br_0.5/BiOCl_0.5Br_0.5The preparation method of the composite solid-solution photocatalyst comprises the following steps:

s1, dissolving the bismuth-containing compound in ethylene glycol to obtain a solution A; mixing a bromine-containing compound and a chlorine-containing compound according to a molar ratio of Br: cl ═ 1:1 is dissolved in the other part of glycol to obtain solution B; wherein the amounts of the bromine-containing compound, the chlorine-containing compound and the bismuth-containing compound are equal; in the solution A, the concentration of the bismuth-containing compound is 0.07-0.2 mol/L; in the solution B, the concentrations of the bromine-containing compound and the chlorine-containing compound are the same, and the value range is 0.08-0.2 mol/L.

S2, dropwise adding the solution B into the solution A, stirring for 20-100 min, uniformly mixing, heating the mixed solution to 140-180 ℃, reacting at a constant temperature for 14-18 h, washing the product with absolute ethyl alcohol, and drying at 60-80 ℃ for 5-24 h to obtain BiOCl_0.5Br_0.5。

S3, adding BiOCl_0.5Br_0.5Adding into distilled water, stirring for 30min to dissolve completely, adding silver-containing compound, stirring at normal temperature for 20-100 min, BiOCl_0.5Br_0.5The molar ratio of the silver-containing compound to the silver-containing compound is 2:1, so as to obtain a solution C; in solution C, BiOCl_0.5Br_0.5The concentration is 0.04-0.1mol/L, and the concentration of the silver-containing compound is 0.02-0.05 mol/L. The silver-containing compound is preferably silver nitrate.

S4, dissolving another chlorine-containing compound and a bromine-containing compound in distilled water to obtain a solution D, wherein the molar ratio of the chlorine-containing compound to the silver-containing compound is 1:1, the molar ratio of the bromine-containing compound to the silver-containing compound is 0.5:1, and the concentration of the chlorine-containing compound in the solution D is 0.02-0.05 mol/L; the concentration of the bromine-containing compound is 0.01 to 0.025 mol/L. Adding the solution D into the solution C, stirring for 1-3 h in the dark, centrifuging, drying at 50-70 ℃ for 8-16 h to obtain AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5；

S5, adding AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5Dissolving in distilled water, irradiating under full-wavelength xenon lamp for 0.5-2 hr, centrifuging, and drying to obtain Ag-AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5A composite photocatalyst is provided.

Preferably, the bismuth-containing compound is bismuth nitrate pentahydrate; the bromine-containing compound is potassium bromide or sodium bromide; the chlorine-containing compound is potassium chloride or sodium chloride.

Preferably, the step S5 may be performed as follows: 0.2-0.5 g of AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5Dissolving the mixture in 20-50 mL of distilled water, irradiating for 0.5-2h under a full-wavelength xenon lamp, centrifuging, and drying for 8-16 h at 50-70 ℃ to obtain Ag-AgCl_0.5Br_0.5/BiOCl_0.5Br_0.5A composite photocatalyst is provided.

Ag-AgCl prepared by the method_0.5Br_0.5/BiOCl_0.5Br_0.5The composite photocatalyst is used for catalyzing, oxidizing and fracturing acrylamide in the flowback fluid under visible light.

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

first, the Ag-AgCl prepared by the invention_0.5Br_0.5/BiOCl_0.5Br_0.5The catalytic activity of the composite solid solution photocatalyst is superior to that of Ag-AgCl_0.5Br_0.5、BiOCl_0.5Br_0.5The photocatalytic activity of the monomer. The prepared photocatalyst can excite more photoproduction electrons under visible light, the electron-hole recombination rate is reduced, the photocatalytic activity is obviously improved, especially, the acrylamide oxide 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 acrylamide in the oxidative fracturing flowback fluid.

Secondly, the invention adopts nontoxic components, reduces the harm to the health of human bodies and the ecological environment, optimizes the preparation process of the photocatalyst and achieves the purposes of reducing the cost and simplifying the production flow. The photocatalyst prepared by the method does not need to be added with other chemical reagents and other preparation post-treatment, and the method is simple.

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

FIG. 1 is Ag-AgCl prepared in example 1_0.5Br_0.5/BiOCl_0.5Br_0.5Composite solid solution photocatalyst, Ag-AgCl_0.5Br_0.5、BiOCl_0.5Br_0.5An XRD spectrum of (b) isFig. a is a partially enlarged view.

FIG. 2 is Ag-AgCl prepared in example 1_0.5Br_0.5/BiOCl_0.5Br_0.5TEM spectra of the composite solid solution photocatalyst.

FIG. 3 is Ag-AgCl prepared in example 1_0.5Br_0.5/BiOCl_0.5Br_0.5Composite solid solution photocatalyst, Ag-AgCl_0.5Br_0.5、BiOCl_0.5Br_0.5Degradation efficiency of acrylamide.

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.