阅读说明：本技术 一种具有分级结构的BiInOCl多孔微球光催化剂及其制备方法 (BiInOCl porous microsphere photocatalyst with hierarchical structure and preparation method thereof ) 是由 李卫兵 张延光 田景 王晓东 方珂 于 2019-10-23 设计创作，主要内容包括：本发明属于光催化技术领域,尤其涉及一种具有分级结构的BiInOCl多孔微球光催化剂；还涉及一种上述具有分级结构的BiInOCl多孔微球光催化剂的制备方法。本发明具有分级结构的BiInOCl多孔微球光催化剂,以硝酸铋,硝酸铟,盐酸,乙二醇为基本原料,通过简单的一步水热法,制得分级结构的BiInOCl多孔微球光催化剂。本发明的优点是光催化性能好,其全光光催化降解诺氟沙星、罗丹明B、甲基橙和亚甲基蓝的性能与现有技术相比均有显著提高。(The invention belongs to the technical field of photocatalysis, and particularly relates to a BiInOCl porous microsphere photocatalyst with a hierarchical structure; also relates to a preparation method of the BiInOCl porous microsphere photocatalyst with the hierarchical structure. The BiInOCl porous microsphere photocatalyst with the hierarchical structure is prepared by taking bismuth nitrate, indium nitrate, hydrochloric acid and ethylene glycol as basic raw materials through a simple one-step hydrothermal method. The invention has the advantages of good photocatalytic performance, and the performance of degrading norfloxacin, rhodamine B, methyl orange and methylene blue by full-light photocatalysis is obviously improved compared with the prior art.)

1. A BiInOCl porous microsphere photocatalyst with a hierarchical structure is characterized in that: bismuth nitrate, indium nitrate, hydrochloric acid and ethylene glycol are used as basic raw materials, and a BiInOCl porous microsphere photocatalyst with a hierarchical structure is prepared by a simple one-step hydrothermal method.

2. The hierarchical BiInOCl porous microsphere photocatalyst as claimed in claim 1, which is characterized in that: the Bi: In of the BiInOCl porous microsphere photocatalyst is 1:0.5, 1:1, 1:2 and 1: 3.

3. The hierarchical BiInOCl porous microsphere photocatalyst as claimed in claim 1, which is characterized in that: the Bi: In ═ 1:2 of the BiInOCl porous microsphere photocatalyst is the optimal proportion.

4. A method for preparing the bi inocl porous microsphere photocatalyst with a hierarchical structure as claimed in any one of claims 1 to 3, which is characterized by comprising the following steps:

(1) preparing sample solutions in different proportions: firstly, 4 beakers with the specification of 100mL are taken, 80mL of ethylene glycol is added, and then 0.4mmol of Bi (NO) is added respectively₃)₃Adding 0.2mmol, 0.4mmol, 0.8mmol and 1.2mmol of In (NO) respectively₃)₃Finally, adding 0.4mmol of HCl solution, and stirring for 30min until the HCl solution is completely dissolved;

(2) hydrothermal reaction: adding the prepared samples with different proportions into a 100mL reaction kettle, and placing the reaction kettle in an electrothermal blowing dry box at the temperature of 140 ℃ for reaction for 24 hours;

(3) washing and drying: and naturally cooling the hydrothermal reaction kettle to room temperature, washing with deionized water, washing with ethanol, and drying at 60 ℃ to obtain the prepared sample.

Technical Field

The invention belongs to the technical field of photocatalysis, and particularly relates to a BiInOCl porous microsphere photocatalyst with a hierarchical structure; the invention also relates to a preparation method of the BiInOCl porous microsphere photocatalyst with the hierarchical structure.

Background

The photocatalytic technology is a green technology with important application prospect in the field of energy and environment, organic dirt can be thoroughly degraded into carbon dioxide and water under the illumination, and meanwhile, the photocatalytic material has no loss and can be recycled, so that the photocatalytic material is widely researched. At present, TiO is the main widely studied photocatalyst₂、 g-C₃N₄、CdS、BiVO₄、WO₃BiOX, etc., wherein BiOX (X ═ Cl, Br, I) is attracting attention as a novel photocatalyst due to its unique electric, optical, catalytic properties, and its unique lamellar structure [ Bi₂O₂]²⁺The built-in electric field formed by the element X can effectively reduce the recombination of photo-generated electrons and holes, and therefore, the photocatalyst has higher photocatalytic activity.

The band structure of BiOX can be adjusted by adjusting X in the BiOX semiconductor. BiOX has a larger atomic number of halogen atom X and a smaller forbidden band width of BiOX, i.e., BiOCl (. about.3.2 eV), BiOBr (. about.2.7 eV), and BiOI (. about.1.7 eV). Researches show that the energy band regulation of the BiOX semiconductor can be realized through the solid solution of the X atoms. E.g. jiaet al by regulating BiOCl_1-xBr_xThe value of x in (x is 0, 0.5, 1) realizes the transition of the forbidden band width from 3.37eV to 2.92eV to 2.83eV, and realizes the simultaneous regulation and control of the conduction band position and the valence band position. Lu et al also found by targeting BiOBr_xI_1-xThe adjustment of x in (x is 0-0.5) can realize BiOBr_xI_1-xAnd adjusting the position of the conduction band, the valence band and the width of the forbidden band. Although the band gap of the semiconductor can be reduced and the photoresponse range of the semiconductor can be widened by the solid solution of the halogen atoms, the energy of free radicals generated by light excitation is reduced due to the band gap shortening, and the full degradation is not facilitated. To widen the semiconductor within a certain rangeThe energy of free radicals can be improved due to the width of the forbidden band, and the energy-saving material has better complete decomposition capability on pollutants or water, so that the material also has very good industrial application value.

Besides regulating the X atom in the BiOX, the regulation of the Bi site atom can also realize the energy band regulation of the BiOX. Since Pb and Bi are positioned in the same period and have similar atomic radii, the regulation and control of the Bi position in BiOX are easy to realize. The research finds that Pb²⁺Can be inserted into [ Bi ]₂O₂]²⁺Interlaminar, Pb 6s²The orbit occupies a higher energy state at the top of a Valence Band (VBM), the Pb 6p orbit occupies a lower energy state at the bottom of a Conduction Band (CBM), and the hybrid states of the VBM and the CBM can respectively reduce the effective mass of holes and electrons, prolong the service life of excited-state carriers and improve the photocatalytic activity. However, Pb is a heavy metal, has strong biological toxicity and causes three-fold harm. Therefore, a more green element is required to be searched for regulating and controlling the Bi bitcell of BiOX so as to realize the regulation of the BiOX energy band structure and better realize the application of the BiOX energy band structure in the field of photocatalysis.

In and Bi are positioned In adjacent periods, In and Bi are both In a valence of +3, and the atomic radius of In is slightly smaller than Bi, so that lattice distortion is likely to occur due to mismatching of the atomic radius In the solid solution process. In addition, In is very easy to hydrolyze to form a local acidic environment, so that the local kinetics of the growth reaction is changed, and the possibility of regulating and controlling the microscopic morphology of the product is realized.

Disclosure of Invention

One of the purposes of the invention is to provide a BiInOCl porous microsphere photocatalyst with a hierarchical structure, which has good photocatalytic performance, and the performance of degrading norfloxacin, rhodamine B, methyl orange and methylene blue by full-light photocatalysis is obviously improved compared with the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme: a BiInOCl porous microsphere photocatalyst with a hierarchical structure is prepared by taking bismuth nitrate, indium nitrate, hydrochloric acid and ethylene glycol as basic raw materials and adopting a simple one-step hydrothermal method.

In of the BiInOCl porous microsphere photocatalyst is 1:0.5, 1:1, 1:2 and 1: 3.

Preferably, In is 1:2 of Bi: In of the Bi In ocl porous microsphere photocatalyst.

Another object of the present invention is to provide a method for preparing a BiInOCl porous microsphere photocatalyst with a hierarchical structure, which comprises the following steps:

(1) preparing sample solutions in different proportions: firstly, 4 beakers with the specification of 100mL are taken, 80mL of ethylene glycol is added, and then 0.4mmol of Bi (NO) is added respectively₃)₃Adding 0.2mmol, 0.4mmol, 0.8mmol and 1.2mmol of In (NO) respectively₃)₃Finally, 0.4mmol of HCl solution is added and stirred for 30min until complete dissolution.

(2) Hydrothermal reaction: the prepared samples with different proportions are added into a 100mL reaction kettle and placed in an electrothermal blowing dry box at 140 ℃ for reaction for 24 hours.

(3) Washing and drying: and naturally cooling the hydrothermal reaction kettle to room temperature, washing with deionized water, washing with ethanol, and drying at 60 ℃ to obtain the prepared sample.

In the invention, the In is dissolved into the BiOCl In a solid way, the structure of the BiOCl still presents a microsphere structure, and the specific surface area is greatly increased. The research on photoelectrochemistry and photocatalysis performance discovers that the BiInOCl-1:2 sample has the best photoelectrochemistry performance and the performance of degrading norfloxacin through photocatalysis. Researches find that the main reasons for improving the photoelectrochemistry and the photocatalytic performance of BiInOCl-1:2 are as follows: firstly, the adsorption capacity of the BiInOCl-1:2 sample is enhanced by the larger specific surface area, and the number of active sites is increased; and secondly, the solid solution of In enables the valence band of BiInOCl to move positively and pulls the conduction band to move negatively, so that the oxidation capability and the reduction capability are enhanced simultaneously. Meanwhile, radical detection shows that a large number of hydroxyl radicals and superoxide radicals exist in the solution at the same time, so that the redox capability of the BiInOCl is improved, and the BiInOCl has higher photoelectrochemistry and photocatalysis performances.

The BiInOCl porous microsphere photocatalyst with the hierarchical structure prepared by the invention has the ratio of Bi to InWhen the ratio is 1:2, the catalyst has the best photoelectrochemical property and the property of degrading norfloxacin by photocatalysis. Under the irradiation of all light, the photo-generated current density is-61.11 muA/cm²The degradation efficiency of the sample to norfloxacin in 5Min BiInOCl-1:2 can reach 96%, and the degradation efficiency is improved by 9.6 times compared with that of pure BiOCl. The research shows that the reason for improving the photocatalytic performance of the BiInOCl-1:2 photocatalyst is as follows: firstly, the large specific surface area of BiInOCl is beneficial to the adsorption of BiInOCl on pollutants, and the number of active sites of BiInOCl is increased; and secondly, the introduction of In enables the valence band of BiInOCl to be positively shifted, the conduction band to be negatively shifted, and the oxidation capability and the reduction capability to be improved. And BiInOCl can generate more superoxide radicals and hydroxyl free radicals compared with BiOCl, so that BiInOCl has stronger oxidizing capability.

Compared with the prior art, the invention has the beneficial effects that:

(1) the BiInOCl solid solution microspheres with high specific surface area are successfully prepared by a simple one-step hydrothermal method, and the preparation method is simple; the large specific surface area of the BiInOCl solid solution can better adsorb substances to be degraded and removed onto active sites, so that the substances are oxidized and removed.

(2) The formation of the BiInOCl solid solution can simultaneously regulate and control the positions of a conduction band and a valence band of BiOCl, so that the conduction band is moved positively and negatively, and the redox capability of photoproduction holes and electrons is enhanced. Meanwhile, BiInOCl can generate more superoxide radicals and hydroxyl radicals compared with BiOCl, so that BiInOCl has stronger oxidizing capability. The BiInOCl solid solution has stronger oxidation-reduction capability, so the BiInOCl solid solution has better application prospect in the aspect of difficultly-degraded pollutants.

Drawings

FIG. 1 is a series of sample SEM topographies;

wherein, FIG. 1A is the SEM morphology of BiOCl, FIG. 1B is the SEM morphology of the In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:0.5) of example 1, FIG. 1C is the SEM morphology of the In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:1) of example 2, FIG. 1D is the SEM morphology of the In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3, and FIG. 1E is the SEM morphology of the In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:3) of example 4;

FIG. 2 is a TEM image under low and high magnification of BiInOCl and the In-solutionized BiInOCl photocatalyst sample of example 3 (BiInOCl-1: 2);

wherein FIG. 2A is a TEM image under a low power lens of BiOCl, FIG. 2B is a TEM image under a high power lens of BiOCl, FIG. 2C is a TEM image under a low power lens of an In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3, and FIG. 2D is a TEM image under a high power lens of an In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3;

FIG. 3 shows the results of the element distribution test of the In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3;

FIG. 4 is an EDS energy spectrum of an In solid solution BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3;

FIG. 5 shows XPS results for BiOCl and the In solid solution BiInOCl photocatalyst sample of example 3 (BiInOCl-1: 2);

wherein, fig. 5A is a total spectrum, fig. 5B is an XPS result of Bi4f, fig. 5C is an XPS result of Cl2p, fig. 5D is an XPS result of O1s, and fig. 5E is an XPS result of In 3D;

FIG. 6 is N for a series of samples₂Adsorption/desorption isotherms and pore size profiles of the series of samples;

wherein, FIG. 6A is N of the series of samples₂Adsorption/desorption isotherms, fig. 6B is a pore size distribution plot for a series of samples;

FIG. 7 is a graph of the UV/VIS diffuse reflectance spectrum and the energy band width of the semiconductor for a series of samples;

wherein, fig. 7A is an ultraviolet/visible diffuse reflection spectrum of the series of samples, and fig. 7B is a band width diagram of a semiconductor of the series of samples;

FIG. 8 shows a series of samples at 0.1mol/L Na₂SO₄A graph of the change of the photo-generated current density in the solution with time;

FIG. 9 is a graph of photocatalytic degradation performance of a series of samples;

wherein, fig. 9A is a graph of the effect of a series of samples on degrading 10mg/L norfloxacin at full light, fig. 9B is a graph of the ultraviolet-visible diffuse reflection absorption spectrum of the In solid solution BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3 on degrading norfloxacin, fig. 9C is a graph of the cycle stability of the In solid solution BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3 on degrading norfloxacin at full light, and fig. 9D is a graph of the degradation effect of the In solid solution BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3 on different materials at full light;

FIG. 10 is the results of testing the electrochemical impedance and Mott Schottky of the In solid solution BiInOCl photocatalyst sample of example 3 (BiInOCl-1: 2);

wherein, FIG. 10A is the electrochemical impedance spectrum of the In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3, FIG. 10B is the Mott Schottky diagram of the In-dissolved BiInOCl photocatalyst sample (BiInOCl-1:2) of example 3,

FIG. 11 is an electron paramagnetic resonance spectrum of BiInOCl and the In solid solution BiInOCl photocatalyst sample of example 3 (BiInOCl-1: 2);

wherein, FIG. 11A is the electron paramagnetic resonance spectrum of the superoxide radical of BiOCl and the BiInOCl photocatalyst sample (BiInOCl-1:2) with In solid solution of example 3, and FIG. 11B is the electron paramagnetic resonance spectrum of the hydroxyl radical of BiOCl and the BiInOCl photocatalyst sample (BiInOCl-1:2) with In solid solution of example 3;

Detailed Description

The following examples are given to facilitate a better understanding of the invention, but do not limit the invention. The experimental procedures in the following examples are conventional unless otherwise specified.