Method for adjusting humidity response range of copper halide

Abstract

The invention discloses a method for adjusting the humidity response range of a copper halide, and relates to the technical field of material improvement, and the method specifically comprises the following steps: grinding the copper halide to obtain the ground copper halide; the chemical general formula of the copper halide is AmCuX3, A is an organic cation, the organic cation comprises an organic ammonium ion and / or an organic phosphine ion, X is a halogen ion, and the value range of m is 1-2. According to the preparation method, the copper halide with the chemical general formula of AmCuX3 is ground, disordered vacancies are introduced into the ordered crystal structure of the copper halide, the change of local charge distribution of the crystal structure is changed, the interaction mode between the material and water molecules is influenced, the copper halide is more sensitive to the existence of trace water, and the water content of the copper halide is reduced. According to the method, the humidity response threshold value of the copper halide is reduced from 100% RH to 75% RH or even lower, so that the copper halide is more suitable for being used in the field of humidity sensors.

Description

Technical Field

[0001] The present invention relates to the technical field of material improvement, and in particular to a method for adjusting the humidity response range of copper halide. Background Art

[0002] Lead-free metal halides are an emerging class of materials with the characteristics of simple synthesis, easy purification, low cost and superior performance. In particular, they can produce changes in photoelectric properties under the stimulation of external light, electricity, heat or chemical substances. Therefore, they are a type of stimulus-responsive material that can regulate luminescence behavior under external stimuli.

[0003] Stimuli-responsive materials combine signal recognition, detection, judgment, and response. Therefore, in addition to their applications in sensing, they can also be applied to fields such as bionic drives, smart homes, and biomedicine.

[0004] The stimulus-responsive materials in existing research usually have a single response pattern and can only produce a single response to the type and intensity of external environmental factors. That is, they can only produce a one-to-one response to a certain external stimulus or to an external stimulus of a certain intensity, and cannot be adjusted to produce variable response behavior. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for adjusting the humidity response range of copper halide and a humidity sensor, aiming to solve the problem in the prior art that stimulus-responsive materials can only produce a single response.

[0006] To achieve the above object, the present invention provides a method for adjusting the humidity response range of copper halide, the method for adjusting the humidity response range of copper halide comprising the following steps:

[0007] grinding the copper halide to obtain ground copper halide;

[0008] The chemical formula of the copper halide is A m CuX3, wherein A is an organic cation including an organic ammonium ion and / or an organic phosphine ion, X is a halogen ion, and the value of m ranges from 1 to 2.

[0009] In one embodiment, the grinding comprises at least one of ball milling, vibration milling, and stirring milling.

[0010] In one embodiment, the grinding comprises ball milling, the frequency of the ball milling is 1 to 20 Hz / s, and the time of the ball milling is 10 to 60 min; and / or,

[0011] The X includes at least one of fluoride ion, chloride ion, bromide ion and iodide ion.

[0012] In one embodiment, the A comprises an organic ammonium ion, and the organic ammonium ion comprises at least one of a primary ammonium ion, a secondary ammonium ion, a tertiary ammonium ion, and a quaternary ammonium ion; and / or,

[0013] The A includes an organic phosphine ion, and the organic phosphine ion includes at least one of a primary phosphine ion, a secondary phosphine ion, a tertiary phosphine ion, and a quaternary phosphine ion.

[0014] In one embodiment, the A comprises an organic ammonium ion containing a polycyclic carbon ring and / or an organic phosphine ion containing a polycyclic carbon ring:

[0015] Wherein, the organic ammonium ion containing a polycyclic carbon ring includes phenyltrimethylammonium ion, phenyldimethylammonium ion, phenylmonomethylammonium ion, benzyltrimethylammonium ion, benzyldimethylmonoethylammonium ion, benzyltriethylammonium ion or phenyltriethylammonium ion,

[0016] The organic phosphine ion containing a polycyclic carbon ring includes phenyltrimethylphosphine ion, phenyldimethylphosphine ion, phenylmonomethylphosphine ion, benzyltrimethylphosphine ion, benzyldimethylmonoethylphosphine ion, benzyltriethylphosphine ion or phenyltriethylphosphine ion.

[0017] In one embodiment, the copper halide is prepared by the following steps:

[0018] S10, mixing cuprous halide, an organic solution containing organic cations, and a solution containing halide ions to obtain a first mixed solution;

[0019] S20, mixing the first mixed solution with a copper halide precipitation promoting agent, and allowing the mixture to stand to obtain a copper halide;

[0020] The halogen element in the cuprous halide is the same as the halogen element in the solution containing halogen ions.

[0021] In one embodiment, in step S10:

[0022] The cuprous halide comprises at least one of cuprous fluoride, cuprous chloride, cuprous bromide and cuprous iodide; and / or,

[0023] The solvent of the organic solution includes N'N-dimethylformamide, acetonitrile or tetrahydrofuran; and / or,

[0024] The solution containing halide ions includes hydroiodic acid, sodium halide aqueous solution or potassium halide aqueous solution; and / or,

[0025] The organic cations in the organic solution of organic cations include organic ammonium ions and / or organic phosphine ions.

[0026] In one embodiment, in step S10:

[0027] The molar concentration of organic cations in the organic solution is 0.25 to 0.5 mol / L, and each gram of cuprous halide is mixed with 15 mL of the organic solution and 0.1 mL of the solution containing halide ions; and / or,

[0028] The mixing includes ultrasonic mixing.

[0029] In one embodiment, in step S20:

[0030] The volume ratio of the first mixed solution to the copper halide precipitation promoting agent is 1:(0.8-1.2); and / or,

[0031] The copper halide precipitation promoting agent includes ether, ethyl acetate or petroleum ether; and / or,

[0032] The standing time is 20 to 24 hours.

[0033] In one embodiment, step S20 includes: mixing the first mixed solution with a copper halide precipitation promoting agent, allowing the mixture to stand, filtering, washing and drying the filter residue to obtain copper halide.

[0034] In the technical solution of the present invention, by m The copper halide of CuX3 (m=1~2) is ground, and disordered vacancies are introduced into the ordered crystal structure of the above copper halide, which changes the local charge distribution of the crystal structure and affects the interaction between the material and water molecules, making the copper halide more sensitive to the presence of trace moisture. In other words, it is more sensitive to humidity and can respond to changes in ambient humidity in real time through changes in the optical properties of the copper halide at lower humidity. This adjustment method reduces the humidity response threshold of the copper halide from 100% RH to 75% RH or even lower, making it more suitable for use in the field of humidity sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0036] Figure 1 Schematic diagram of the structure of the copper halide luminescent material in Example 1 of the present invention;

[0037] Figure 2 The X-ray diffraction patterns of the unground copper halide of the present invention and the ground copper halide in Example 1;

[0038] Figure 3 1 is a fluorescence spectrum of the unground copper halide of the present invention and the ground copper halide in Example 1;

[0039] Figure 4 1 is a water vapor adsorption diagram of the unground copper halide of the present invention and the ground copper halide in Example 1;

[0040] Figure 5 Graphs showing the fluorescence responses of the unground copper halide of the present invention and the ground copper halide of Example 1 under different humidity conditions.

[0041] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. Where the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in this field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] Lead-free metal halides are an emerging class of materials with the characteristics of simple synthesis, easy purification, low cost and superior performance. In particular, they can produce changes in photoelectric properties under the stimulation of external light, electricity, heat or chemical substances. Therefore, they are a type of stimulus-responsive material that can regulate luminescence behavior under external stimuli.

[0044] Stimuli-responsive materials combine signal recognition, detection, judgment, and response. Therefore, in addition to their applications in sensing, they can also be applied to fields such as bionic drives, smart homes, and biomedicine.

[0045] The stimulus-responsive materials in existing research usually have a single response mode and can only produce a single response to the type and intensity of external environmental factors. That is, they can only respond to a certain type of external stimulus or to external stimulus of a certain intensity. The response range is narrow and cannot be adjusted.

[0046] In view of this, the present invention provides a method for adjusting the humidity response range of copper halide, the method for adjusting the humidity response range of copper halide comprising the following steps: grinding copper halide to obtain ground copper halide; the chemical formula of the copper halide is A m CuX3, wherein A is an organic cation including an organic ammonium ion and / or an organic phosphine ion, X is a halogen ion, and the value of m ranges from 1 to 2.

[0047] In the technical solution of the present invention, by m By grinding copper halide CuX3 (m=1-2), disordered vacancies are introduced into the ordered crystal structure of the copper halide. This changes the local charge distribution of the crystal structure, affecting the interaction between the material and water molecules, making the copper halide more sensitive to the presence of trace amounts of moisture. This makes it more sensitive to humidity and can react to changes in ambient humidity in real time at lower humidity levels through changes in the copper halide's optical properties. This regulation method reduces the humidity response threshold of the copper halide from 100% RH to 75% RH or even lower, making it more suitable for use in humidity sensors. RH stands for relative humidity.

[0048] In some embodiments, the grinding includes at least one of ball milling, vibration milling, and stirring milling. It is understood that grinding is used to provide radial force. In this application, the copper halide A can be adjusted by ball milling, vibration milling, or stirring milling. m The humidity response of CuX3 (m=1~2) is the lowest.

[0049] In some embodiments, the grinding includes ball milling, the frequency of the ball milling is 1 to 20 Hz / s, and the time of the ball milling is 10 to 60 minutes. Compared with other mechanical forces or grinding methods, ball milling can be used to quickly grind copper halide A. m More disordered defects and vacancies are generated inside and on the surface of CuX3 (m=1-2) crystals. These defects and vacancies can serve as active sites to increase the copper halide A m The interaction between CuX3 (m=1~2) and external water molecules.

[0050] In some embodiments, X comprises at least one of fluoride, chloride, bromide, and iodide. It is understood that the radius of the four halide ions increases and their water solubility decreases in descending order. Bromide and iodide, due to their larger ion size and lower energy band gap, exhibit superior photoelectric performance for humidity sensors.

[0051] In some embodiments, A comprises an organic ammonium ion, wherein the organic ammonium ion comprises at least one of a primary ammonium ion, a secondary ammonium ion, a tertiary ammonium ion, and a quaternary ammonium ion; and / or A comprises an organic phosphine ion, wherein the organic phosphine ion comprises at least one of a primary phosphine ion, a secondary phosphine ion, a tertiary phosphine ion, and a quaternary phosphine ion. It is understood that as the number of hydrogen atoms attached to nitrogen atoms in the primary ammonium ion, the secondary ammonium ion, the tertiary ammonium ion, and the quaternary ammonium ion is replaced by hydrocarbon chains, the minimum humidity response of the copper halide increases, and a similar pattern is observed for the organic phosphine ion.

[0052] In some embodiments, A comprises an organic ammonium ion containing a polycyclic carbocyclic ring and / or an organic phosphine ion containing a polycyclic carbocyclic ring: wherein the organic ammonium ion containing a polycyclic carbocyclic ring comprises phenyltrimethylammonium ion, phenyldimethylammonium ion, phenylmonomethylammonium ion, benzyltrimethylammonium ion, benzyldimethylmonoethylammonium ion, benzyltriethylammonium ion, or phenyltriethylammonium ion; and the organic phosphine ion containing a polycyclic carbocyclic ring comprises phenyltrimethylphosphine ion, phenyldimethylphosphine ion, phenylmonomethylphosphine ion, benzyltrimethylphosphine ion, benzyldimethylmonoethylphosphine ion, benzyltriethylphosphine ion, or phenyltriethylphosphine ion. It is understood that when the organic ammonium ion contains a polycyclic carbocyclic ring, the minimum humidity response value increases compared to that of the halide, enabling a fluorescence response effect at a lower relative humidity range.

[0053] In some embodiments, the copper halide is prepared by the following steps: S10, mixing cuprous halide, an organic solution containing organic cations, and a solution containing halide ions to obtain a first mixed solution; S20, mixing the first mixed solution with a copper halide precipitation-promoting agent, and allowing to stand to obtain copper halide; the halogen element in the cuprous halide is the same as the halogen element in the solution containing halide ions. It is understood that the solution containing halide ions is used to promote the dissolution of cuprous halide in the system. The copper halide-promoting agent can be a poor solvent that promotes the precipitation of copper halide, or it can be other agents that change the solution environment (such as pH value, temperature, etc.) to promote the formation and precipitation of copper halide.

[0054] In some embodiments, in step S10: the cuprous halide includes at least one of cuprous fluoride, cuprous chloride, cuprous bromide, and cuprous iodide; and / or the solvent of the organic solution includes N'N dimethylformamide, acetonitrile, or tetrahydrofuran; and / or the solution containing halide ions includes hydrohalic acid, an aqueous sodium halide solution, or an aqueous potassium halide solution; and / or the organic cations in the organic solution of organic cations include organic ammonium ions and / or organic phosphine ions. It is understood that the solvent of the above-mentioned organic solution is used to better dissolve the compound providing the organic cation. Selecting the above-mentioned solution containing halide ions can better increase the dissolution rate of the cuprous halide in the system.

[0055] In some embodiments, in step S10, the molar concentration of the organic cation in the organic solution is 0.25 to 0.5 mol / L, and each gram of cuprous halide is mixed with 15 mL of the organic solution and 0.1 mL of the solution containing halide ions; and / or the mixing includes ultrasonic mixing. When the ratio of the organic cation concentration in the organic solvent, the cuprous halide, and the solution containing halide ions is within the above range, the components can be quickly and evenly dissolved and fully contacted, facilitating subsequent precipitation to obtain copper halide.

[0056] In some embodiments, in step S20: the volume ratio of the first mixed liquid to the copper halide precipitation-promoting agent is 1: (0.8-1.2); and / or the copper halide precipitation-promoting agent includes ether, ethyl acetate or petroleum ether; and / or the standing time is 20-24 hours. It is understandable that the volume ratio of the first mixed liquid to the copper halide precipitation-promoting agent can be 1:0.8, 1:1 or 1:1.2, and the volume ratio within the above range can ensure that the copper halide in the first mixed liquid is quickly precipitated. Preferably, the copper halide precipitation-promoting agent is ether, and the standing time after using the copper halide precipitation-promoting agent can be 20 hours, 22 hours or 24 hours. The standing time within the above range can ensure that the copper halide is more thoroughly crystallized and precipitated. In some embodiments, step S20 includes: mixing the first mixed liquid with the copper halide precipitation-promoting agent, standing, filtering, washing and drying the filter residue to obtain copper halide.

[0057] The present invention further provides a humidity sensor comprising copper halide adjusted by the aforementioned method for adjusting the humidity response range of copper halide. Therefore, the sensor has all the beneficial effects of the aforementioned method for adjusting the humidity response range of copper halide, which will not be described in detail here.

[0058] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0059] Example 1

[0060] A method for adjusting the humidity response range of copper halide comprises the following steps:

[0061] The copper halide [PhMe3]2CuI3 (wherein PhMe3 is phenyltrimethylammonium ion) is ball milled with a ball mill at a frequency of 20 Hz / s and a ball milling time of 30 min to obtain a copper halide with an adjusted humidity response range.

[0062] Wherein, copper halide is prepared by the following steps:

[0063] 0.2 g of cuprous iodide was added to 3 mL of a N'N' dimethylformamide solution of phenyltrimethylammonium iodide (the concentration of phenyltrimethylammonium iodide in the N'N' dimethylformamide solution was 0.33 mol / L); 0.3 mL of hydroiodic acid was then added to the resulting solution, and ultrasonically dissolved for 15 minutes to obtain a first mixed solution; 10 mL of ether was added to the first mixed solution, and the mixture was allowed to stand for 24 hours. The obtained product was filtered, washed, and dried to obtain a copper halide [PhMe3]2CuI3. The structure of the obtained copper halide [PhMe3]2CuI3 is as follows: Figure 1 shown.

[0064] Example 2

[0065] Compared with Example 1, Example 2 is different in that:

[0066] The phenyltrimethylammonium iodide in Example 1 was replaced with tetramethylammonium iodide.

[0067] Example 3

[0068] Compared with Example 2, Example 3 is different in that:

[0069] The phenyltrimethylammonium iodide in Example 2 was replaced by trimethylammonium iodide.

[0070] Comparative Example 1

[0071] Comparative Example 1 is different from Example 1 in that:

[0072] The copper halide in Example 1 was replaced by [PhMe3]3Cu3I6.

[0073] Performance Testing

[0074] The unground copper halide and the ground copper halide in Example 1 were subjected to X-ray diffraction analysis, fluorescence spectrum analysis, water vapor adsorption analysis, and fluorescence response analysis under different humidity conditions. The fluorescence response analysis test method under different humidity conditions is as follows: the copper halide powder is placed in an environment with different humidity and left to stand for 2 hours, then taken out and observed under a 365nm ultraviolet lamp, and then a fluorescence test is performed.

[0075] The results are as follows Figure 2 、 Figure 3 、 Figure 4 and Figure 5 shown.

[0076] Depend on Figure 2 It can be seen that the copper halide [PhMe3]2CuI3 material in Example 1 has good crystallinity before being ground, but its crystallinity is reduced after the grinding treatment and turns into an amorphous state; Figure 3It can be seen that the position of the fluorescence emission peak of the copper halide [PhMe3]2CuI3 material in Example 1 does not change with grinding; Figure 4 It can be seen that the water vapor adsorption curve of the copper halide [PhMe3]2CuI3 material in Example 1 changes with grinding, which proves that grinding can change the response of the material in Example 1 at a single humidity, for example, the response is enhanced at a humidity of 80%. Figure 5 It can be seen that the fluorescence response of the copper halide [PhMe3]2CuI3 material in Example 1 under 75% humidity can be regulated by grinding. There is no response before grinding, but color change behavior can be observed after grinding.

[0077] The copper halides after grinding in Examples 1-3 and Comparative Example 1 were subjected to fluorescence response analysis under different humidity conditions. The relative humidity RH at which the fluorescence response occurs is called the humidity response threshold. The humidity response thresholds of the four groups of copper halides after grinding were recorded. The results are shown in Table 1.

[0078] Table 1 Humidity response thresholds of copper halides after grinding in Examples 1-3 and Comparative Example 1

[0079] Humidity response threshold (%) Example 1 75％ Example 2 50％ Example 3 30％ Comparative Example 1 No response

[0080] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. A method for adjusting the humidity response range of copper halide, characterized in that: The method for adjusting the copper halide humidity response range comprises the following steps: grinding the copper halide to obtain ground copper halide; The chemical formula of the copper halide is A m CuX3, wherein A is an organic cation including an organic ammonium ion and / or an organic phosphine ion, X is a halogen ion, and the value of m ranges from 1 to 2.

2. The method for adjusting the humidity response range of copper halide according to claim 1, wherein: The grinding includes at least one of ball milling, vibration milling and stirring milling.

3. The method for adjusting the humidity response range of copper halide according to claim 2, wherein: The grinding includes ball milling, the frequency of the ball milling is 1 to 20 Hz / s, and the time of the ball milling is 10 to 60 minutes; and / or, The X includes at least one of fluoride ion, chloride ion, bromide ion and iodide ion.

4. The method for adjusting the humidity response range of copper halide according to claim 1, wherein: The A comprises organic ammonium ions, and the organic ammonium ions comprise at least one of primary ammonium ions, secondary ammonium ions, tertiary ammonium ions, and quaternary ammonium ions; and / or, The A includes an organic phosphine ion, and the organic phosphine ion includes at least one of a primary phosphine ion, a secondary phosphine ion, a tertiary phosphine ion, and a quaternary phosphine ion.

5. The method for adjusting the humidity response range of copper halide according to claim 1, wherein: Said A comprises an organic ammonium ion containing a polycyclic carbon ring and / or an organic phosphine ion containing a polycyclic carbon ring: Wherein, the organic ammonium ion containing a polycyclic carbon ring includes phenyltrimethylammonium ion, phenyldimethylammonium ion, phenylmonomethylammonium ion, benzyltrimethylammonium ion, benzyldimethylmonoethylammonium ion, benzyltriethylammonium ion or phenyltriethylammonium ion, The organic phosphine ion containing a polycyclic carbon ring includes phenyltrimethylphosphine ion, phenyldimethylphosphine ion, phenylmonomethylphosphine ion, benzyltrimethylphosphine ion, benzyldimethylmonoethylphosphine ion, benzyltriethylphosphine ion or phenyltriethylphosphine ion.

6. The method for adjusting the humidity response range of copper halide according to claim 1, wherein: The copper halide is prepared by the following steps: S10, mixing cuprous halide, an organic solution containing organic cations, and a solution containing halide ions to obtain a first mixed solution; S20, mixing the first mixed solution with a copper halide precipitation promoting agent, and allowing the mixture to stand to obtain a copper halide; The halogen element in the cuprous halide is the same as the halogen element in the solution containing halogen ions.

7. The method for adjusting the humidity response range of copper halide according to claim 6, wherein: In step S10: The cuprous halide comprises at least one of cuprous fluoride, cuprous chloride, cuprous bromide and cuprous iodide; and / or, The solvent of the organic solution includes N'N-dimethylformamide, acetonitrile or tetrahydrofuran; and / or, The solution containing halide ions includes hydrohalic acid, sodium halide aqueous solution or potassium halide aqueous solution; and / or, The organic cations in the organic solution of organic cations include organic ammonium ions and / or organic phosphine ions.

8. The method for adjusting the humidity response range of copper halide according to claim 6, wherein: In step S10: The molar concentration of organic cations in the organic solution is 0.25 to 0.5 mol / L, and each gram of cuprous halide is mixed with 15 mL of the organic solution and 0.1 mL of the solution containing halide ions; and / or, The mixing includes ultrasonic mixing.

9. The method for adjusting the humidity response range of copper halide according to claim 6, wherein: In step S20: The volume ratio of the first mixed solution to the copper halide precipitation promoting agent is 1:(0.8-1.2); and / or, The copper halide precipitation promoting agent includes diethyl ether, ethyl acetate or petroleum ether; and / or, The standing time is 20 to 24 hours.

10. The method for adjusting the humidity response range of copper halide according to claim 6, wherein: Step S20 includes: mixing the first mixed solution with a copper halide precipitation promoting agent, allowing the mixture to stand, filtering, washing and drying the filter residue to obtain copper halide.

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