KR20180097973A - Discoloration sensor and method of manufacturing the same - Google Patents

Abstract

Discoloration sensor of the present invention comprises a perovskite compound including a structure of CH3NH3PbI3 and a detection unit having the perovskite compound. In the present invention, when the detection unit is exposed to the volatile organic compound, the volatile organic compound is changed by a reaction of the perovskite and presence of the volatile organic compound can be confirmed.

Description

TECHNICAL FIELD [0001] The present invention relates to a discoloration sensor,

More particularly, the present invention relates to a pyridine color change sensor including a perovskite compound and a method of manufacturing the same.

Since the important developments in the world industry and economy in recent years, the detection and monitoring of pollutants with high sensitivity has become very important both socially and environmentally. In particular, volatile organic compounds (VOCs) such as alcohols, acetone, formaldehyde, and pyridine are widely used as indoor environmental pollutants, It is known.

Volatile organic compounds (VOCs) are volatile organic compounds that volatilize in the atmosphere and cause odor and ozone. These compounds are substances that cause damage to the nervous system through skin contact and inhalation. Such volatile organic compounds often cause odor even at low concentrations, and the compounds themselves may be directly harmful to the environment and human body or participate in photochemical reaction in the atmosphere to generate secondary pollutants such as photochemical oxides.

Among them, pyridine (C ₅ H ₅ N), widely used as a general-purpose solvent in industrial organic synthesis, can be inhaled, ingested or absorbed through the skin, causing nausea, vomiting, coughing, asthma breathing, laryngitis and even cancer do. Even more serious is that the pyridine gas is colorless and therefore difficult to recognize even if it is exposed to it. Therefore, there is a demand for a pyridine monitoring system that combines high sensitivity and rapid detection and reliability in various environments.

It has so far been used in the field of barbituric acid spectrophotometry, liquid chromatography, gas chromatography, liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry gas chromatography-mass spectrometry) have been reported. However, a reversible detection system that signals color or color emissions has not yet been reported.

An object of the present invention is to provide a color shift sensor for pyridine detection.

Another object of the present invention is to provide a method for producing a color change sensor for pyridine detection.

Color change sensor for an object of the present invention is a perovskite (perovskite) a compound having the structure of CH ₃ NH ₃ PbI _3; And a detection unit including the perovskite compound. When the detection unit is exposed to volatile organic compounds (VOCs), the reaction of the volatile organic compound and the perovskite causes color change or fluorescence of the detection unit The presence or absence of the volatile organic compound can be confirmed.

In one embodiment, the volatile organic compound may be pyridine.

In one embodiment, the detector may be a perovskite film in the form of a thin film.

In one embodiment, the perovskite film may have a thickness of 200 nm to 400 nm.

In one embodiment, the perovskite film may have a uniform crystal domain of less than 5 [mu] m.

In one embodiment, the change may be a visible change.

In one embodiment, when exposed to pyridine, the detector can change transparently in dark brown within 5 seconds.

In one embodiment, when the pyridine is exposed to pyridine, the detector may change to dark brown within 10 seconds.

In one embodiment, the reaction may be a reversible reaction.

In one embodiment, at least one of the absorbance and fluorescence intensity of the detection unit may be reversibly changed by reacting with pyridine.

In one embodiment, the absorbance change may reversibly change the absorbance at a wavelength range of 450 nm to 800 nm.

In one embodiment, the fluorescence intensity change can reversibly change the fluorescence intensity at the 780 nm wavelength band.

Discoloration sensor manufacturing method for the detection of volatile organic compounds for the object of the present invention may include the steps of preparing a substrate and CH ₃ NH ₃ PbI ₃ precursor; The step of CH ₃ NH ₃ PbI coating blade (blade-coating) a _third precursor into a blade coater (blade-coater) onto the substrate to form a wet film; Drying the wet film to form a dried film; And annealing the dried film.

In one embodiment, the gap between the blade coater and the substrate is 10 μm, and the blade coating can be performed at a coating rate of 15 mm / s.

In one embodiment, the dried film can be annealed at 100 DEG C for 15 minutes.

According to the present invention, it is possible to provide a color shift sensor for pyridine detection which is excellent in sensitivity, durability and coloring property for detecting pyridine gas which is a volatile organic compound. The pyridine-detecting discoloration sensor of the present invention is excellent in sensitivity and can detect pyridine quickly. Also, when exposed to pyridine vapors, they show reversible and visible color changes, so that pyridine can be repeatedly monitored and pyridine can be easily recognized visually.

1 is a diagram showing the crystal structure of the perovskite functional dye of the present invention.
2 is a diagram showing the characteristics of the perovskite.
3 is a diagram showing the characteristics of the perovskite.
4 is a view showing a manufacturing method of the present invention.
5 is a view showing a perovskite film of the present invention.
6 is a view showing an experimental apparatus for perovskite film of the present invention.
7 is a diagram showing the result of the experiment.
8 is a diagram showing the results of the experiment.
9 is a view showing a perovskite film of the present invention.
10 is a diagram showing the result of the experiment.
11 is a view showing an experimental result.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the term " comprises " or " having ", etc. is intended to specify that there is a feature, step, operation, element, part or combination thereof described in the specification, , &Quot; an ", " an ", " an "

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

A perovskite compound is a substance having the structure of the formula ABX _{3 wherein} A is an organic cation, B is a metal cation, and X is a halogen anion.

FIG. 1 is a diagram showing the crystal structure of perovskite functional dye of the present invention. Referring to FIG. 1, there is shown the structure of a perovskite functional pigment comprising an organic cation CH ₃ NH ₃ ⁺ , a metal cation Pb ²⁺ and a halogen anion I ^- .

The organometal halide-type hybrid perovskite of the ABX ₃ structure is an excellent light harvester. It is an intense broadband UV / Vis optical fiber compared to conventional light absorbing ruthenium based molecular pigments. Excellent optoelectronic properties such as absorption (300 nm to 800 nm) and 10 times larger absorption coefficient (ε = 1.3 × 10 ⁵ cm ^-1 , 550 nm) have been revealed. By combining this unique optical property with the hydrogen bonding reactivity of the polar species of the perovskite, a perovskite functional dye (PFD) was applied to the polar chemical sensor.

Color change sensor for an object of the present invention is a perovskite (perovskite) a compound having the structure of CH ₃ NH ₃ PbI _3; And a detection unit including the perovskite compound. When the detection unit is exposed to volatile organic compounds (VOCs), the reaction of the volatile organic compound and the perovskite causes color change or fluorescence of the detection unit The presence or absence of the volatile organic compound can be confirmed.

In one embodiment, the volatile organic compound may be pyridine.

Typical organometallic halide perovskite materials show irreversible conversion of crystal structure in response to moisture (polar material) and are well known according to the following chemical reaction formula.

CH ₃ NH ₃ PbI ₃  → CH ₃ NH ₃ I + PbI ₂

This reaction is caused by the interaction between the hydrogen atom of CH ₃ NH ^3+. Conventionally, polar alcohols (such as methanol, ethanol, n-propanol, and n-butanol) convert the crystal structure of perovskite into irreversible principles Although it has been discovered, it has been observed in the present invention that the interaction between the pyridine molecule and perovskite is reversible.

Figs. 2 to 3 are diagrams showing perovskite characteristics. Fig.

Referring to Figure 2, the distance between the polar molecules H ₂ O, EtOH, and the CH ₃ NH ₃ ⁺ of pyridine and perovskite is shown. At this time, the farther the distance between the two molecules is, the weaker the interaction strength can be, and the reversible reaction may occur.

Also, referring to FIG. 3, it is shown that the energy of the perovskite-pyridine complex is relatively higher than the total energy of the perovskite and pyridine molecules, respectively. When the energy of the complex is relatively high, a reversible reaction is possible, and the energy of the perovskite-H ₂ O complex is relatively low, which hinders the reversible reaction. Therefore, it can be seen from Figs. 2 to 3 that, unlike the other polar molecules, perovskite is effective for reversibly detecting pyridine.

In one embodiment, the detector may be a perovskite film in the form of a thin film.

In one embodiment, the perovskite film may have a thickness of 200 nm to 400 nm.

In one embodiment, the perovskite film may have a uniform crystal domain of less than 5 [mu] m.

In one embodiment, the change may be a visible change.

In the present invention, the use of polarity-recognizable organometallic halide perovskite functional pigments is used to produce super fast (< 1 s) polar pyridine vapor (polarity: ET = 45.4 kcal / mol) ) And a simple yet highly effective pyridine chemical sensor that exhibits a reversible and visible colorimetric / fluorescent response. Compared to other sensing materials reported in the past, the preparation of perovskite films is not only a simple one step synthesis but also a low-cost solution printing process that is compatible with a wide range of chemicals It is applicable to sensor array (chemosensor arrays).

Hereinafter, embodiments of the present invention will be described in detail. However, the following examples are only a few embodiments of the present invention, and the present invention should not be construed as being limited to the following examples.

Material preparation

Methylammonium iodide (CH ₃ NH ₃ I) and lead (II) iodide (PbI ₂ ), Tokyo Chemical Industry (TCI).

Dimethyl sulfoxide (DMSO) and pyridine, Sigma-Aldrich.

Manufacture of perovskite film

In one embodiment of the present invention, a CH ₃ NH ₃ PbI ₃ perovskite precursor solution was CH ₃ NH ₃ I and PbI ₂ , and a glass substrate was used as a substrate for forming a perovskite film.

Before forming the perovskite film, the substrate was cleaned by sonication in detergent and deionized water, acetone and isopropyl alcohol.

A homogeneous and large area (10 cm ² ) perovskite film on a cleaned substrate was coated with a blade-coater and homogeneous CH ₃ NH ₃ PbI ₃ perovskite precursor solution (homogeneous CH ₃ NH ₃ PbI ₃ precursor solution) was prepared using DMSO. At this time, by performing blade-coating of the precursor solution at a coating speed of 15 mm / s with a gap of 10 μm between the blade and the substrate, a perovskite having a thickness of 400 nm or less is obtained I could.

The precursor solution was dried at room temperature (25 캜) for 40 minutes until the wet film formed immediately after the bladed solution was annealed to wait for most of the DMSO to evaporate (blade coating was performed with a knife- coating device) (KP-3000H, KIPAE). Finally, the dried substrate was annealed at 100 DEG C for 15 minutes.

4 is a view showing a manufacturing method of the present invention. Specifically, FIG. 4 is a diagram illustrating formation of a large area perovskite film on a glass substrate using a precursor solution using a blade coater in the process of producing the perovskite film of the present invention. At this time, the thickness of the perovskite film can be adjusted by a gap. The crystalline perovskite film is formed by drying the wet film and then annealing at 100 ° C.

UV-vis absorption of perovskite films prepared by the above examples using Agilent 8457 UV-vis spectrophotometer, Shimadzu RF-5301PC fluorescence spectrophotometer and MCPD-3000 (Otsuka Electronics) And PL (photoluminescence) spectra were measured.

Characterization of the manufactured perovskite film

5 is a view showing a perovskite film of the present invention. Referring to FIG. 5, a scanning electron microscopy (SEM) image of the perovskite film of the present invention shows a uniform crystal domain of 5 μm or less (scale bar: 10 μm).

In one embodiment, when exposed to pyridine, the detector can change transparently in dark brown within 5 seconds.

In one embodiment, when the pyridine is exposed to pyridine, the detector may change to dark brown within 10 seconds.

In one embodiment, the reaction may be a reversible reaction.

In one embodiment, at least one of the absorbance and fluorescence intensity of the detection unit may be reversibly changed by reacting with pyridine.

In one embodiment, the absorbance change may decrease in absorbance at a wavelength range of 450 nm to 800 nm.

In one embodiment, the fluorescence intensity change can reversibly change the fluorescence intensity at the 780 nm wavelength band.

UV / Vis absorption spectra of perovskite films were investigated in the presence of pyridine vapor to confirm the pyridine recognition ability of perovskite films.

6 is a view showing an experimental apparatus for perovskite film of the present invention. Specifically, in order to measure the change in optical characteristics of the perovskite film of the present invention, the experimental apparatus shown in FIG. 6 was used. The perovskite film was exposed to pyridine gas carried by nitrogen gas (4.0 x 102 mL / min) at room temperature (25 캜).

7 is a diagram showing the result of the experiment. 7, broad band absorption spectra were observed from the perovskite film of the present invention, characterized by a peak at 745 nm. When exposed to pyridine vapor, the peak wavelength of 55.4 %, As well as a decrease in overall absorbance in the visible spectra range. It shows the decomposition of the perovskite crystal structure, and the visible change in the color of the perovskite becomes clear. The pyridine-induced transparency of the perovskite films was 55.3, 62.9 and 59.3% at 500, 600 and 700 nm, respectively. Such absorption and clarity (transparency) changes the pyridine and CH ₃ NH ^{3 +} hydrogen bonding between the interactive color of the film changes to be determined which are caused by the decomposition (hydrogen bond interaction), from dark brown to clear (no color) It happens.

8 is a diagram showing the results of the experiment. Referring to FIG. 8, the absorbance and color of the perovskite film are restored to their original values after 6 seconds after removing the pyridine vapor. 7 to 8, the reversible absorbance and color change of the perovskite film can be confirmed.

9 is a view showing a perovskite film of the present invention. Specifically, Fig. 9 (a) shows the appearance of the perovskite film before being exposed to the pyridine vapor. (B), (c) and (d) The change in color of the lobesquot film is shown in order of time. FIGS. 9 (e), 9 (f), 9 (g) and 9 (h) show the change of the perovskite film in time sequence when the pyridine vapor is removed. 9, a rapid and reversible change in perovskite with respect to the pyridine vapor can be confirmed.

10 to 11 are diagrams showing experimental results.

Referring to FIG. 10, PL (photoluminescence) spectra of the perovskite films before and after exposure to pyridine are compared. At 780 nm, 65.2% of the initial fluorescence intensity sharply decreases when exposed to pyridine vapors, indicating recovery after pyridine vapor removal. These results confirm that the perovskite functional dye sensitively responds.

The reproducibility of reversible pyridine vapor detection of perovskite films was confirmed by repeated exposure and removal of pyridine vapor to the perovskite film to monitor absorbance and fluorescence changes.

Referring to FIG. 11, FIG. 11 (a) shows the change in the luminous intensity of light according to the cyclic pyridine vapor exposure and removal cycle, and FIG. 11 (b) The interaction between pyridine and perovskite is reversible through the cycle and has excellent durability that can be used many times. More than 100 pyridine exposure cycles may be repeated. The fastest pyridine vapor detection (off) and recovery (on) times were less than 1 second and less than 6 seconds, respectively.

Discoloration sensor manufacturing method for the detection of volatile organic compounds for the object of the present invention may include the steps of preparing a substrate and CH ₃ NH ₃ PbI ₃ precursor; The step of CH ₃ NH ₃ PbI coating blade (blade-coating) a _third precursor into a blade coater (blade-coater) onto the substrate to form a wet film; Drying the wet film to form a dried film; And annealing the dried film.

In one embodiment, the gap between the blade coater and the substrate is 10 μm, and the blade coating can be performed at a coating rate of 15 mm / s.

In one embodiment, the dried film can be annealed at 100 DEG C for 15 minutes.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. It can be understood that it is possible.

Claims (15)

Fe lobe having the structure of CH ₃ NH ₃ PbI ₃ Sky agent (perovskite) compound; And
And a detection unit including the perovskite compound
Wherein the detector detects a change in color or fluorescence of the detection unit due to the reaction between the volatile organic compound and the perovskite when the detection unit is exposed to volatile organic compounds,
Discoloration sensor.
The method according to claim 1,
Wherein the volatile organic compound is pyridine.
Discoloration sensor.
The method according to claim 1,
Characterized in that the detector is a perovskite film in the form of a thin film,
Discoloration sensor.
The method of claim 3,
Wherein the perovskite film has a thickness of 200 nm to 400 nm.
Discoloration sensor.
The method of claim 3,
Wherein the perovskite film has a uniform crystal domain of 5 mu m or less.
Discoloration sensor.
The method according to claim 1,
Characterized in that the change is a visible change.
Discoloration sensor.
3. The method of claim 2,
And the detection part changes transparently in a dark brown color within 5 seconds when exposed to pyridine.
Discoloration sensor.
8. The method of claim 7,
Wherein when the pyridine is removed after pyridine exposure, the detector changes to a dark brown color within 10 seconds.
Discoloration sensor.
The method according to claim 1,
Wherein the reaction is a reversible reaction.
Discoloration sensor.
3. The method of claim 2,
Wherein at least one of the absorbance and the fluorescence intensity of the detection unit is reversibly changed by reacting with pyridine,
Discoloration sensor.
11. The method of claim 10,
Wherein the absorbance change reversibly changes the absorbance at a wavelength range of 450 nm to 800 nm.
Discoloration sensor.
11. The method of claim 10,
Wherein the fluorescence intensity change reversibly changes the fluorescence intensity at a wavelength band of 780 nm.
Discoloration sensor
Preparing a substrate and CH ₃ NH ₃ PbI ₃ precursor;
The step of CH ₃ NH ₃ PbI coating blade (blade-coating) a _third precursor into a blade coater (blade-coater) onto the substrate to form a wet film;
Drying the wet film to form a dried film; And
And annealing the dried film to detect a volatile organic compound,
A method of manufacturing a discoloration sensor.
14. The method of claim 13,
Characterized in that the distance between the blade coater and the substrate is 10 占 퐉 and the blade coating is carried out at a coating speed of 15 mm /
A method of manufacturing a discoloration sensor.
14. The method of claim 13,
Characterized in that the dried film is annealed at 100 DEG C for 15 minutes.
A method of manufacturing a discoloration sensor.

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