阅读说明：本技术 片层状CoxSe纳米片阵列太阳能电池电极的自主装制备方法 (Lamellar CoxSelf-assembly preparation method of Se nanosheet array solar cell electrode ) 是由 王中旭 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种片层状Co-(x)Se纳米片阵列太阳能电池电极的自主装制备方法,对FTO玻璃进行清洁处理,之后,浸入溶液中进行预处理,获得预处理的FTO玻璃；步骤2、在所述预处理的FTO玻璃上形成种子层；步骤3、将所述步骤2获得的FTO玻璃同时置于反应釜中并且浸没在反应釜溶液中,进行溶剂热反应,冷却后取出,用无水乙醇冲洗3～5次,干燥后得到片层状硒化钴纳米片阵列电极。本发明通过自主装的方式,选择合适的种子层诱导,并结合特定工艺的溶剂热法,可以在无模板条件下制备择优生长的纳米片层状Co-(x)Se阵列并形成电极片；制备出Co-(x)Se纳米片阵列太阳能电极,具有择优生长取向,可以显著提高电池的性能。(The invention discloses lamellar Co x The self-assembly preparation method of the Se nanosheet array solar cell electrode comprises the steps of cleaning FTO glass, and then immersing the FTO glass into a solution for pretreatment to obtain pretreated FTO glass; step 2, forming a seed layer on the pretreated FTO glass; and 3, simultaneously placing the FTO glass obtained in the step 2 in a reaction kettle and immersing the FTO glass in a reaction kettle solution, carrying out solvothermal reaction, cooling and taking out, washing for 3-5 times by using absolute ethyl alcohol, and drying to obtain the lamellar cobalt selenide nanosheet array electrode. Book (I)The invention can prepare the nanosheet layered Co growing preferentially under the template-free condition by selecting a proper seed layer for induction in an autonomous assembly mode and combining a solvothermal method of a specific process x Se array and forming electrode plates; preparation of Co x The Se nanosheet array solar electrode has preferred growth orientation, and can remarkably improve the performance of the cell.)

1. Lamellar Co_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized by comprising the following steps:

step 1, cleaning FTO glass, and then immersing the FTO glass into a solution for pretreatment to obtain pretreated FTO glass;

step 2, forming a seed layer on the pretreated FTO glass;

and 3, simultaneously placing the FTO glass obtained in the step 2 in a reaction kettle and immersing the FTO glass in a reaction kettle solution, carrying out solvothermal reaction, cooling and taking out, washing for 3-5 times by using absolute ethyl alcohol, and drying to obtain the lamellar cobalt selenide nanosheet array electrode.

2. Lamellar Co according to claim 1_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized by comprising the following steps of 1: potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) With potassium tert-butoxide (C)₄H₉OK), dissolving in a mixed solution of deionized water and ethanol, magnetically stirring to obtain a transparent solution, and then immersing the cleaned FTO glass in the solution for pretreatment for 30 minutes to obtain the pretreated FTO glass.

3. Lamellar Co according to claim 2_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized in that the step 1 is implemented specifically according to the following steps:

step 1.1, preparing a mixed solution of deionized water and ethanol according to a volume ratio of 2-5: 1, and then adding potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) Magnetically stirring for 20-40 minutes to form a uniform solution;

step 1.2 to the solution formed in step 1.1, potassium tert-butoxide (C) was added slowly₄H₉OK), stirring, and adjusting the pH value to be 11-12;

step 1.3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein the FTO glass is cleaned for 2-4 times in 20-40 minutes every time, so as to obtain clean FTO glass;

step 1.4, placing the clean FTO glass into the solution obtained in step 1.2;

and step 1.5, preserving the heat for 20-40 minutes at the temperature of 115-185 ℃, and maintaining magnetic stirring at the rotating speed of 500-600 r/min to obtain the pretreated FTO glass.

4. Lamellar Co according to any of claims 1 to 3_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized in that the step 2 specifically comprises the following steps: putting the FTO glass pretreated in the step 1 into cobalt acetate (C)₄H₆CoO₄) Dissolving in citric acid (C)₆H₈O₇) And slowly hydrolyzing the mixture in deionized water at a low temperature, and then processing the mixture at a high temperature to generate the FTO glass with the seed layer.

5. Lamellar Co according to claim 4_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized in that the step 2 is implemented according to the following steps:

step 2.1, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving the mixture in deionized water to prepare a solution with the molar concentration of Co ions of 0.35-0.65 mol/L;

step 2.2, adding citric acid (C) into the solution of step 2.1₆H₈O₇) Adjusting the pH value to 4-5;

2.3, placing the FTO glass pretreated in the step 1 into the liquid obtained in the step 2.2, and slowly raising the temperature to 30-50 ℃ at a temperature raising speed of 0.35-0.65 ℃ per minute;

and 2.4, directly taking out the FTO glass obtained in the step 2.3, drying the FTO glass in an infrared drying oven at the temperature of 210-390 ℃ for 40-80 minutes, taking out the FTO glass, and washing the FTO glass with ionized water for 3-5 times to obtain the FTO glass with the seed layer.

6. Lamellar Co according to claim 5_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized in that the reaction kettle solution in the step 3 is prepared specifically according to the following steps:

step 3.1, weighing cobalt chloride (CoCl) respectively₂) Is cobalt source, sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 0.55-1.15: 1;

step 3.2 with ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) The solvent is ethylene diamine and toluene, and the volume ratio of ethylene diamine to toluene is 3-5: 1;

and 3.3, dissolving the weighed cobalt chloride and sodium selenate into 140-240 ml of mixed solution of ethylenediamine and methylbenzene, and magnetically stirring for 1-2 hours at the temperature of 20-30 ℃ until a transparent solution, namely a reaction kettle solution is formed, wherein the rotating speed of the magnetic stirring is 500-600 r/min.

7. Lamellar Co according to claim 6_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized in that the step 3 is implemented specifically according to the following steps:

step 3.4, transferring the reaction kettle solution obtained in the step 3.3 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 2 into the reaction kettle solution to be placed at an angle of 30-60 degrees;

step 3.5, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 210-310 ℃, and preserving heat for 13-20 hours at the heating rate of 0.5-1.5 ℃ per minute;

step 3.6, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 3-5 times, and drying in a vacuum drying oven; the temperature is 60-100 ℃ and the time is 0.7-1.4 hours, and Co can be obtained_xSe nanosheet array electrode.

8. Lamellar Co according to claim 7_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is characterized in that the lining of the hydrothermal reaction kettle is polytetrafluoroVinyl fluoride.

Technical Field

The invention belongs to the technical field of preparation methods of electrode materials of solar cells, and particularly relates to lamellar Co_xAn autonomous assembling preparation method of a Se nanosheet array solar cell electrode.

Background

As the VI group element, Se has stronger metallicity, and the metal selenide shows excellent conductive performance; in addition, Se has larger atomic radius and lower ionization energy than S of the same family, so that the metal selenide shows unique catalytic property, and Cu_xSe, PbSe and Co_xSe and other metal selenides are the most widely researched counter electrode materials at present, cobalt selenide has excellent electrochemical activity, and the light absorption coefficient is as high as 10⁵The band gap is only 1.5-1.7 eV per cm, and the nanostructure with a large specific surface area is easy to synthesize, so the material becomes a hot spot concerned for electrode materials.

By regulating and controlling the grain size of the cobalt selenide, a stronger quantum confinement effect can be shown, and the catalytic activity can be further enhanced.

The SILAR method has been reported in the literature to be able to synthesize Cu on FTO by successive ion layer deposition_1.8A Se counter electrode; a hydrothermal method can also be adopted to prepare a transparent binary Co-Se alloy counter electrode and hollow spherical CoSe; co is also successfully prepared by a solvothermal synthesis method₉Se₈a/CoSe counter electrode.

Cobalt selenide is generally classified into CoSe having semiconductor characteristics and Co having metal alloy properties_0.85Se, non-stoichiometric integer ratio of Co due to overlap of Se 4p and Co 3d spintronic orbitals_0.85Se has remarkable catalytic property and conductivity; thus, Co_0.85Se has been widely studied as an electrode material, Co_0.85The Se electrode is prepared by a sol-gel method or a hydrothermal method, and the final form is Co_0.85Se thin film, but has a problem that the specific surface area is low and the growth cannot be preferred.

Disclosure of Invention

In view of the above, the main object of the present invention is to provide a lamellar Co_xAutonomous assembling system of Se nanosheet array solar cell electrodeThe preparation method is that.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the embodiment of the invention provides lamellar Co_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is implemented according to the following steps:

step 1, cleaning FTO glass, and then immersing the FTO glass into a solution for pretreatment to obtain pretreated FTO glass;

step 2, forming a seed layer on the pretreated FTO glass;

and 3, simultaneously placing the FTO glass obtained in the step 2 in a reaction kettle and immersing the FTO glass in a reaction kettle solution, carrying out solvothermal reaction, cooling and taking out, washing for 3-5 times by using absolute ethyl alcohol, and drying to obtain the lamellar cobalt selenide nanosheet array electrode.

In the above scheme, the step 1 specifically comprises: potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) With potassium tert-butoxide (C)₄H₉OK), dissolving in a mixed solution of deionized water and ethanol, magnetically stirring to obtain a transparent solution, and then immersing the cleaned FTO glass in the solution for pretreatment for 30 minutes to obtain the pretreated FTO glass.

In the above scheme, the step 1 is specifically implemented according to the following steps:

step 1.1, preparing a mixed solution of deionized water and ethanol according to a volume ratio of 2-5: 1, and then adding potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) Magnetically stirring for 20-40 minutes to form a uniform solution;

step 1.2 to the solution formed in step 1.1, potassium tert-butoxide (C) was added slowly₄H₉OK), stirring, and adjusting the pH value to be 11-12;

step 1.3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein the FTO glass is cleaned for 2-4 times in 20-40 minutes every time, so as to obtain clean FTO glass;

step 1.4, placing the clean FTO glass into the solution obtained in step 1.2;

and step 1.5, preserving the heat for 20-40 minutes at the temperature of 115-185 ℃, and maintaining magnetic stirring at the rotating speed of 500-600 r/min to obtain the pretreated FTO glass.

In the above scheme, the step 2 specifically comprises: putting the FTO glass pretreated in the step 1 into cobalt acetate (C)₄H₆CoO₄) Dissolving in citric acid (C)₆H₈O₇) And slowly hydrolyzing the mixture in deionized water at a low temperature, and then processing the mixture at a high temperature to generate the FTO glass with the seed layer.

In the above scheme, the step 2 is specifically implemented according to the following steps:

step 2.1, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving the mixture in deionized water to prepare a solution with the molar concentration of Co ions of 0.35-0.65 mol/L; a pH value of

Step 2.2, adding citric acid (C) into the solution of step 2.1₆H₈O₇) Adjusting the pH value to 4-5;

2.3, placing the FTO glass pretreated in the step 1 into the liquid obtained in the step 2.2, and slowly raising the temperature to 30-50 ℃ at a temperature raising speed of 0.35-0.65 ℃ per minute;

and 2.4, directly taking out the FTO glass obtained in the step 2.3, drying the FTO glass in an infrared drying oven at the temperature of 210-390 ℃ for 40-80 minutes, taking out the FTO glass, and washing the FTO glass with ionized water for 3-5 times to obtain the FTO glass with the seed layer.

In the above scheme, the reaction kettle solution in step 3 is specifically prepared according to the following steps:

step 3.1, weighing cobalt chloride (CoCl) respectively₂) Is cobalt source, sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 0.55-1.15: 1;

step 3.2 with ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) The solvent is ethylene diamine and toluene, and the volume ratio of ethylene diamine to toluene is 3-5: 1;

and 3.3, dissolving the weighed cobalt chloride and sodium selenate into 140-240 ml of mixed solution of ethylenediamine and methylbenzene, and magnetically stirring for 1-2 hours at the temperature of 20-30 ℃ until a transparent solution, namely a reaction kettle solution is formed, wherein the rotating speed of the magnetic stirring is 500-600 r/min.

In the above scheme, the step 3 is specifically implemented according to the following steps:

step 3.4, transferring the reaction kettle solution obtained in the step 3.3 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 2 into the reaction kettle solution to be placed at an angle of 30-60 degrees;

step 3.5, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 210-310 ℃, and preserving heat for 13-20 hours at the heating rate of 0.5-1.5 ℃ per minute;

step 3.6, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 3-5 times, and drying in a vacuum drying oven; the temperature is 60-100 ℃ and the time is 0.7-1.4 hours, and Co can be obtained_xSe nanosheet array electrode.

In the above scheme, the lining of the hydrothermal reaction kettle is polytetrafluoroethylene.

Compared with the prior art, the method can prepare the nanosheet-shaped Co with preferred growth under the template-free condition by selecting a proper seed layer for induction in an autonomous assembly mode and combining a solvothermal method of a specific process_xSe array and forming electrode plates; preparation of Co_xThe Se nanosheet array solar electrode has preferred growth orientation, and can remarkably improve the performance of the cell.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic view showing a lamellar Co sheet according to example 1 of the present invention_xCo prepared by self-assembly preparation method of Se nanosheet array solar cell electrode_0.85A topography of the Se nanosheet array solar cell electrode;

FIG. 2 is a schematic view of example 2 of the present invention to provide a lamellar Co_xSe nanosheet array sunCo prepared by self-assembly preparation method of energy battery electrode_0.55A topography of the Se nanosheet array solar cell electrode;

FIG. 3 is a view showing a lamellar Co sheet according to example 3 of the present invention_xCo prepared by self-assembly preparation method of Se nanosheet array solar cell electrode_1.15A topography of the Se nanosheet array solar cell electrode;

FIG. 4 is a view showing a lamellar Co sheet according to example 4 of the present invention_xCo prepared by self-assembly preparation method of Se nanosheet array solar cell electrode_0.65And (3) a topography of the Se nanosheet array solar cell electrode.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, article, or apparatus that comprises the element.

The embodiment of the invention provides lamellar Co_xThe self-assembly preparation method of the Se nanosheet array solar cell electrode is implemented according to the following steps:

step 1, cleaning FTO glass, and then immersing the FTO glass into a solution for pretreatment to obtain pretreated FTO glass;

specifically, potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) With potassium tert-butoxide (C)₄H₉OK)，Dissolving the mixed solution in deionized water and ethanol, magnetically stirring the mixed solution to obtain a transparent solution, and then immersing the cleaned FTO glass into the solution for pretreatment for 30 minutes to obtain the pretreated FTO glass.

Step 2, forming a seed layer on the pretreated FTO glass;

specifically, the FTO glass pretreated in the step 1 is put into cobalt acetate (C)₄H₆CoO₄) Dissolving in citric acid (C)₆H₈O₇) And slowly hydrolyzing the mixture in deionized water at a low temperature, and then processing the mixture at a high temperature to generate the FTO glass with the seed layer.

And 3, simultaneously placing the FTO glass obtained in the step 2 in a reaction kettle and immersing the FTO glass in a reaction kettle solution, carrying out solvothermal reaction, cooling and taking out, washing for 3-5 times by using absolute ethyl alcohol, and drying to obtain the lamellar cobalt selenide nanosheet array electrode.

Further, the step 1 is specifically implemented according to the following steps:

step 1.1, preparing a mixed solution of deionized water and ethanol according to a volume ratio of 2-5: 1, and then adding potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) Magnetically stirring for 20-40 minutes to form a uniform solution;

step 1.2 to the solution formed in step 1.1, potassium tert-butoxide (C) was added slowly₄H₉OK), stirring, and adjusting the pH value to be 11-12;

step 1.3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein the FTO glass is cleaned for 2-4 times in 20-40 minutes every time, so as to obtain clean FTO glass;

step 1.4, placing the clean FTO glass into the solution obtained in step 1.2;

and step 1.5, preserving the heat for 20-40 minutes at the temperature of 115-185 ℃, and maintaining magnetic stirring at the rotating speed of 500-600 r/min to obtain the pretreated FTO glass.

The step 2 is specifically implemented according to the following steps:

step 2.1, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving the mixture in deionized water to prepare a solution with the molar concentration of Co ions of 0.35-0.65 mol/L;

step 2.2, adding citric acid (C) into the solution of step 2.1₆H₈O₇) Adjusting the pH value to 4-5;

2.3, placing the FTO glass pretreated in the step 1 into the liquid obtained in the step 2.2, and slowly raising the temperature to 30-50 ℃ at a temperature raising speed of 0.35-0.65 ℃ per minute;

and 2.4, directly taking out the FTO glass obtained in the step 2.3, drying the FTO glass in an infrared drying oven at the temperature of 210-390 ℃ for 40-80 minutes, taking out the FTO glass, and washing the FTO glass with ionized water for 3-5 times to obtain the FTO glass with the seed layer.

The step 3 is specifically implemented according to the following steps:

step 3.1, weighing cobalt chloride (CoCl) respectively₂) Is cobalt source, sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 0.55-1.15: 1;

step 3.2 with ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) The solvent is ethylene diamine and toluene, and the volume ratio of ethylene diamine to toluene is 3-5: 1;

3.3, dissolving weighed cobalt chloride and sodium selenate into 140-240 ml of mixed solution of ethylenediamine and methylbenzene, and magnetically stirring for 1-2 hours at the temperature of 20-30 ℃ until a transparent solution, namely a reaction kettle solution, is formed, wherein the rotating speed of magnetic stirring is 500-600 r/min;

step 3.4, transferring the reaction kettle solution obtained in the step 3.3 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 2 into the reaction kettle solution to be placed at an angle of 30-60 degrees;

step 3.5, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 210-310 ℃, and preserving heat for 13-20 hours at the heating rate of 0.5-1.5 ℃ per minute;

step 3.6, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 3-5 times, and drying in a vacuum drying oven; the temperature is 60-100 ℃ and the time is 0.7-1.4 hours, and Co can be obtained_xSe nanosheet array electrode.

The inner liner of the hydrothermal reaction kettle is made of polytetrafluoroethylene.

Example 1

Example 1 of the present invention provides a lamellar Co_0.85The self-assembly preparation method of the Se nanosheet array solar cell electrode is implemented according to the following steps:

step 1, preparing a mixed solution of deionized water and ethanol according to a volume ratio of 3:1, and then adding potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) Magnetically stirring for 30 minutes to form a uniform solution;

step 2, slowly adding potassium tert-butoxide (C) into the solution formed in the step 1₄H₉OK), stirring, and adjusting the pH value to be 11-12;

step 3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein the FTO glass is ultrasonically cleaned for 30 minutes for 3 times each time to obtain clean FTO glass;

step 4, placing the clean FTO glass into the solution obtained in the step 2;

step 5, preserving the heat for 30 minutes at 150 ℃, and maintaining the magnetic stirring at the rotating speed of 550r/min to obtain pretreated FTO glass;

step 6, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving in deionized water to prepare a solution with the molar concentration of Co ions being 0.5 mol/L;

step 7, adding citric acid (C) into the solution obtained in step 6₆H₈O₇) Adjusting the pH value to 4;

step 8, placing the FTO glass pretreated in the step 5 into the liquid obtained in the step 2.2, and slowly raising the temperature to 40 ℃ at a temperature raising speed of 0.5 ℃ per minute;

step 9, directly taking out the FTO glass obtained in the step 8, drying the FTO glass in an infrared drying oven at the temperature of 300 ℃ for 60 minutes, taking out the FTO glass, and washing the FTO glass with ionized water for 4 times to obtain the FTO glass with a seed layer;

step 10, weighing cobalt chloride (CoCl) respectively₂) Is a cobalt source and is used as a cobalt source,sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 0.85: 1;

step 11, using ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) Is a solvent, and the volume ratio of ethylenediamine to toluene is 4: 1;

step 12, dissolving weighed cobalt chloride and sodium selenate into 200ml of mixed solution of ethylenediamine and methylbenzene, and magnetically stirring for 1.5 hours at the temperature of 20-30 ℃ until a transparent solution, namely a reaction kettle solution, is formed, wherein the rotating speed of magnetic stirring is 550 r/min;

step 13, transferring the reaction kettle solution obtained in the step 12 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 9 into the reaction kettle solution to be placed at an angle of 45 degrees;

step 14, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 260 ℃, and preserving heat for 16 hours, wherein the heating rate is 1 DEG/min;

step 15, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 3-5 times, and drying in a vacuum drying oven; the temperature is 80 ℃ and the time is 1 hour, and then Co can be obtained_0.85Se nanosheet array electrode.

As shown in FIG. 1, it can be seen that Co prepared by the present invention_0.85The Se electrode has obvious nano-sheet shape and clear and uniform distribution.

Example 2

Example 2 of the present invention provides a lamellar Co_0.55The self-assembly preparation method of the Se nanosheet array solar cell electrode is implemented according to the following steps:

step 1, preparing a mixed solution of deionized water and ethanol according to a volume ratio of 2:1, and then adding potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) Magnetically stirring for 20 minutes to form a uniform solution;

step 2, slowly adding potassium tert-butoxide (C) into the solution formed in the step 1₄H₉OK), stirring, and adjusting the pH value to be 11-12;

step 3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein the FTO glass is ultrasonically cleaned for 2 times for 20 minutes each time to obtain clean FTO glass;

step 4, placing the clean FTO glass into the solution obtained in the step 2;

step 5, preserving the heat for 20 minutes at the temperature of 115 ℃, and maintaining magnetic stirring at the rotating speed of 500-600 r/min to obtain pretreated FTO glass;

step 6, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving in deionized water to prepare a solution with the molar concentration of Co ions being 0.35 mol/L;

step 7, adding citric acid (C) into the solution obtained in step 6₆H₈O₇) Adjusting the pH value to 4-5;

step 8, placing the FTO glass pretreated in the step 5 into the liquid obtained in the step 2.2, and slowly raising the temperature to 30 ℃ at a temperature raising speed of 0.35 ℃ per minute;

step 9, directly taking out the FTO glass obtained in the step 8, drying the FTO glass in an infrared drying oven at the temperature of 210 ℃ for 40 minutes, taking out the FTO glass, and washing the FTO glass for 3 times by using ionized water to obtain the FTO glass with the seed layer;

step 10, weighing cobalt chloride (CoCl) respectively₂) Is cobalt source, sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 0.55: 1;

step 11, using ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) Is a solvent, and the volume ratio of ethylenediamine to toluene is 3: 1;

step 12, dissolving weighed cobalt chloride and sodium selenate into 140ml of mixed solution of ethylenediamine and toluene, and magnetically stirring for 1h at the temperature of 20 ℃ until a transparent solution, namely a reaction kettle solution, is formed, wherein the magnetic stirring speed is 500 r/min;

step 13, transferring the reaction kettle solution obtained in the step 12 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 9 into the reaction kettle solution to be placed at an angle of 30 degrees;

step 14, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 210 ℃, and keeping the temperature for 13 hours, wherein the heating rate is 0.5 ℃ per minute;

step 15, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 3 times, and drying in a vacuum drying oven; the temperature is 60 ℃ and the time is 0.7 hour, and then the Co can be obtained_0.55Se nanosheet array electrode.

As shown in FIG. 2, it can be seen that Co prepared by the present invention_0.55The Se nanosheet array solar cell electrode has obvious nanosheet shape, clear shape and uniform distribution.

Example 3

Example 3 of the present invention provides a lamellar Co_1.15The self-assembly preparation method of the Se nanosheet array solar cell electrode is implemented according to the following steps:

step 1, preparing a mixed solution of deionized water and ethanol according to a volume ratio of 5:1, and then adding potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) Magnetically stirring for 40 minutes to form a uniform solution;

step 2, slowly adding potassium tert-butoxide (C) into the solution formed in the step 1₄H₉OK), stirring, and adjusting the pH value to be 11-12;

step 3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein the FTO glass is cleaned for 4 times after being ultrasonically cleaned for 40 minutes each time, so as to obtain clean FTO glass;

step 4, placing the clean FTO glass into the solution obtained in the step 2;

step 5, preserving the heat for 40 minutes at 185 ℃, and maintaining magnetic stirring at the rotating speed of 600r/min to obtain pretreated FTO glass;

step 6, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving in deionized water to prepare a solution with the molar concentration of Co ions being 0.65 mol/L;

step 7, adding citric acid (C) into the solution obtained in step 6₆H₈O₇) Adjusting the pH value to 5;

step 8, placing the FTO glass pretreated in the step 5 into the liquid obtained in the step 2.2, and slowly raising the temperature to 50 ℃ at a temperature raising speed of 0.65 ℃ per minute;

step 9, directly taking out the FTO glass obtained in the step 8, drying the FTO glass in an infrared drying oven at 390 ℃ for 80 minutes, taking out the FTO glass, and washing the FTO glass for 5 times by using ionized water to obtain the FTO glass with a seed layer;

step 10, weighing cobalt chloride (CoCl) respectively₂) Is cobalt source, sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 1.15: 1;

step 11, using ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) Is a solvent, and the volume ratio of ethylenediamine to toluene is 5: 1;

step 12, dissolving weighed cobalt chloride and sodium selenate into 240ml of mixed solution of ethylenediamine and methylbenzene, and magnetically stirring for 1-2 hours at the temperature of 20-30 ℃ until a transparent solution, namely a reaction kettle solution, is formed, wherein the rotating speed of magnetic stirring is 500-600 r/min;

step 13, transferring the reaction kettle solution obtained in the step 12 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 9 into the reaction kettle solution to be placed at an angle of 60 degrees;

step 14, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 310 ℃, and preserving heat for 20 hours at the heating rate of 1.5 ℃ per minute;

step 15, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 3-5 times, and drying in a vacuum drying oven; the temperature is 100 ℃, the time is 1.4 hours, and Co can be obtained_1.15Se nanosheet array electrode.

As shown in FIG. 3, it can be seen that Co prepared by the present invention_1.15The Se nanosheet array solar cell electrode has obvious nanosheet shape, clear shape and uniform distribution.

Example 4

Example 4 of the present invention provides a lamellar Co_0.65The self-assembly preparation method of the Se nanosheet array solar cell electrode is implemented according to the following steps:

step 1, preparing deionized water and ethanol according to the volume ratio of 2.5:1Then potassium monododecyl phosphate (C) is added₁₂H₂₅OPO₃K₂) Magnetically stirring for 25 minutes to form a uniform solution;

step 2, slowly adding potassium tert-butoxide (C) into the solution formed in the step 1₄H₉OK), stirring, and adjusting the pH value to be 11-12;

step 3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein ultrasonic cleaning is carried out for 25 minutes each time and cleaning is carried out for 3 times, so as to obtain clean FTO glass;

step 4, placing the clean FTO glass into the solution obtained in the step 2;

step 5, preserving the heat for 25 minutes at 140 ℃, and maintaining magnetic stirring at the rotating speed of 500-600 r/min to obtain pretreated FTO glass;

step 6, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving in deionized water to prepare a solution with the molar concentration of Co ions being 0.4 mol/L;

step 7, adding citric acid (C) into the solution obtained in step 6₆H₈O₇) Adjusting the pH value to 4-5;

step 8, placing the FTO glass pretreated in the step 5 into the liquid obtained in the step 2.2, and slowly raising the temperature to 35 ℃ at a temperature raising speed of 0.4 ℃ per minute;

step 9, directly taking out the FTO glass obtained in the step 8, drying the FTO glass in an infrared drying oven at the temperature of 240 ℃ for 50 minutes, taking out the FTO glass, and washing the FTO glass with ionized water for 4 times to obtain the FTO glass with a seed layer;

step 10, weighing cobalt chloride (CoCl) respectively₂) Is cobalt source, sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 0.65: 1;

step 11, using ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) Is a solvent, and the volume ratio of ethylenediamine to toluene is 3: 1;

step 12, dissolving weighed cobalt chloride and sodium selenate into 160ml of mixed solution of ethylenediamine and toluene, and magnetically stirring for 1.5 hours at 25 ℃ until a transparent solution, namely a reaction kettle solution, is formed, wherein the magnetic stirring speed is 530 r/min;

step 13, transferring the reaction kettle solution obtained in the step 12 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 9 into the reaction kettle solution to be placed at an angle of 40 degrees;

step 14, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 240 ℃, and keeping the temperature for 15 hours, wherein the heating rate is 0.8 ℃ per minute;

step 15, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 3 times, and drying in a vacuum drying oven; the temperature is 75 ℃ and the time is 0.9 hour, and then the Co can be obtained_0.65Se nanosheet array electrode.

As shown in FIG. 4, it can be seen that Co prepared by the present invention_0.65The Se nanosheet array solar cell electrode has obvious nanosheet shape, clear shape and uniform distribution.

Example 5

Example 5 of the present invention provides a lamellar Co_1.10The self-assembly preparation method of the Se nanosheet array solar cell electrode is implemented according to the following steps:

step 1, preparing a mixed solution of deionized water and ethanol according to a volume ratio of 4:1, and then adding potassium monododecyl phosphate (C)₁₂H₂₅OPO₃K₂) Magnetically stirring for 35 minutes to form a uniform solution;

step 2, slowly adding potassium tert-butoxide (C) into the solution formed in the step 1₄H₉OK), stirring, and adjusting the pH value to be 12;

step 3, ultrasonically cleaning the FTO glass in dilute nitric acid, deionized water and absolute ethyl alcohol respectively, wherein the FTO glass is cleaned for 3 times after being ultrasonically cleaned for 35 minutes each time, so as to obtain clean FTO glass;

step 4, placing the clean FTO glass into the solution obtained in the step 2;

step 5, preserving the heat for 35 minutes at 160 ℃, and maintaining magnetic stirring at the rotating speed of 580r/min to obtain pretreated FTO glass;

step 6, under the ice-bath condition, cobalt acetate (C)₄H₆CoO₄) Dissolving in deionized water to prepare a solution with the molar concentration of Co ions being 0.55 mol/L;

step 7, adding citric acid (C) into the solution obtained in step 6₆H₈O₇) Adjusting the pH value to 4-5;

step 8, placing the FTO glass pretreated in the step 5 into the liquid obtained in the step 2.2, and slowly raising the temperature to 46 ℃ at a temperature raising speed of 0.55 ℃ per minute;

step 9, directly taking out the FTO glass obtained in the step 8, drying for 70 minutes in an infrared drying oven at 350 ℃, taking out, and washing for 4 times by using ionized water to obtain the FTO glass with the seed layer;

step 10, weighing cobalt chloride (CoCl) respectively₂) Is cobalt source, sodium selenate (Na)₂SeO₃) Is a selenium source, and the molar ratio of Co to Se is 1.10: 1;

step 11, using ethylenediamine (C)₂H₈N₂) And toluene (C)₈H₁₀) The volume ratio of ethylenediamine to toluene is 4.5: 1;

step 12, dissolving weighed cobalt chloride and sodium selenate into 230ml of mixed solution of ethylenediamine and toluene, and magnetically stirring the mixture for 1 time at the temperature of 25 ℃ until a transparent solution, namely a reaction kettle solution, is formed, wherein the magnetic stirring speed is 580 r/min;

step 13, transferring the reaction kettle solution obtained in the step 12 into a hydrothermal reaction kettle, and immersing the FTO glass with the seed layer obtained in the step 9 into the reaction kettle solution to be placed at an angle of 55 degrees;

step 14, sealing the reaction kettle, placing the reaction kettle in a high-temperature oven, heating to 300 ℃, and preserving heat for 18 hours at the heating rate of 1.2 ℃ per minute;

step 15, cooling the hydrothermal kettle to room temperature, taking out, washing with absolute ethyl alcohol for 5 times, and drying in a vacuum drying oven; the temperature is 90 ℃ and the time is 1.2 hours, and then Co can be obtained_1.10Se nanosheet array electrode.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.