KR102132471B1 - Transition metal doped ATO nanoparticles for photochemical and electrochemical oxidation of bio material - Google Patents

Abstract

The present invention relates to ATO nanoparticles doped with transition metals for photochemical and electrochemical oxidation of biological materials.
When the ATO nanoparticles doped with a transition metal according to the present invention are applied to an electrode, it exhibits a high current value, so that it is possible to oxidize biomaterials by photochemical and electrochemical methods. I can measure the amount of my biological material.

Description

Transition metal doped ATO nanoparticles for photochemical and electrochemical oxidation of bio material}

The present invention relates to ATO nanoparticles doped with transition metals for photochemical and electrochemical oxidation of biological materials.

Tin oxide (SnO ₂ ) is well known as one of the smart materials, and is used in applications such as solar batteries, catalyst supports, and chemical sensors.

Tin oxide (SnO ₂ ) has been used as a catalyst in many gas conversions, especially including carbon monoxide (CO), nitrogen dioxide (NO ₂ ) and some hydrocarbons.

However, tin oxide (SnO ₂₎ the case of using as a catalyst, since less efficient, tin, and is still a need to enhance the catalytic action of the oxide (SnO _2), a metal (metal) or catalyzed by inserting anions (anion) Although attempts have been made to improve the process, these processes have to keep in mind the cost and efficiency of the prepared catalysts, and thus have limited access.

As a method of modifying a tin oxide (SnO ₂ ) catalyst, antimony (Sb) is doped with tin oxide (SnO ₂ ) (antimony-doped tin oxide; hereinafter'ATO'), and tin (Sn) 5s state Since is associated with catalytic activity, this state has been shown to contribute to electrical conductivity.

However, when ATO nanoparticles are applied to the application field, a problem that a desired catalyst efficiency cannot be obtained occurs, and a solution to this problem is urgent.

Republic of Korea Patent Publication No. 2018-0072542

An object of the present invention is to provide nanoparticles having improved photocatalytic activity by doping a transition metal with tin dioxide nanoparticles doped with antimony.

Further, the present invention has an object to provide an electrode capable of measuring the amount of a biological material in a sample and a sensor including the same, by oxidizing the biological material by a photochemical and electrochemical method using the nanoparticle as a photocatalyst. .

In order to achieve the above object, the present invention, in one embodiment, a transition metal; And antimony-tin oxide (AT0), wherein the transition metal provides nanoparticles doped on the oxide surface.

In addition, the present invention, in one embodiment, provides an electrode comprising a mixture of the nanoparticles and a solid electrolyte.

In addition, the present invention, in one embodiment, provides a sensor including the electrode.

When the ATO nanoparticles doped with a transition metal according to the present invention are applied to an electrode, it exhibits a high current value, so that it is possible to oxidize biomaterials by photochemical and electrochemical methods. I can measure the amount of my biological material.

1 is a transmission electron microscope (hereinafter referred to as'TEM') image of ATO nanoparticles doped with 5 mol% of Cr(a), Mn(b), Fe(c), and Mn(d) (left). , Their size distribution (middle) and X-ray diffraction (hereinafter referred to as'XRD') spectrum (right).
2 is an X-ray absorption spectroscopy (hereinafter referred to as'XAS') spectrum of Sn M _4,5 -edge (top), O K-edge (middle) and L _2,3 -edge (bottom). It is the figure shown.
FIG. 3 shows the CV curve of pure GCE with or without 10 mM Cys (red) in PBS solution at a scan rate of 50 mV/s (black).
Figure 4 is a pure GCE (black line), Cr (a), Mn (b), Fe (c) and Mn (d) doped ATO nanoparticles modified GCE (red line) cysteine (L-cysteine) ;'Cys') Cyclic Voltametry when performed at a scan rate of 50 mV/s in a solution containing 10 mM and Phosphate-buffered saline (hereinafter'PBS') 'CV') Curve (a to d), ATO doped with transition metals (Cr, Mn, Fe and Mn) It is a diagram showing the catalytic current (e) measured from the electrochemical oxidation of Cys for nanoparticles.
5 is ATO doped with 5 mol% Cr(a), Mn(b), Fe(c), and Co(d). High Resolution Photoemisson Spectroscopy (hereinafter'HRPES') S 2p core-level spectrum (a to d), Cys for the product of photocatalytic oxidation of Cys (180 l solution) in the presence of nanoparticles Cr, Mn, Fe and Co doped ATO when 365 nm UV light is applied to Cys (180 ℓ solution) to evaluate each photocatalytic activity for oxidation of This diagram shows the ratio of S3 to S1 (e) for nanoparticles.
FIG. 6 shows ATO doped with Cr(a), Mn(b), Fe(c) and Co(d) grown on a silicon substrate. A diagram showing the conversion rate of carbon dioxide (CO ₂ ) gas (300K) to oxygen (O ₂ ) and carbon monoxide (CO) gas (1 × 10 ^-6 torr) for the amount of various doped metals and the substrate temperature in the presence of nanoparticles. to be.
Figure 7 is ATO doped with Cr It shows HRPES data of nanoparticles, HRPES data of O 1s and Sn 3d as Cr dopant increases to 1 mol% (top), 3 mol% (middle), 5 mol% (bottom), Cr 2p HRPES data (top right) and Cr dopant HRPES data of valence band (bottom right) with increasing to 1 mol% (black), 3 mol% (red), 5 mol% (blue) It is a figure showing.
8 is an MTO doped ATO Shows HRPES data of nanoparticles, HRPES data of O 1s and Sn 3d as Mn dopant increases to 1 mol% (top), 3 mol% (middle), 5 mol% (bottom), Mn 2p HRPES data (top right) and Mn dopant is 1 mol% (black), 3 mol% (red), 5 mol% (blue) HRPES data (lower right) of the valence band is a diagram showing the increase .
9 is an ATO doped with Fe HRPES data of nanoparticles, HRPES data of O 1s and Sn 3d as Fe dopant increases to 1 mol% (top), 3 mol% (middle), 5 mol% (bottom), Fe 2p HRPES data (top right) and Fe dopant is 1 mol% (black), 3 mol% (red), 5 mol% (blue) HRPES data (bottom right) of the valence band is a diagram showing the increase .
10 is an ATO doped with Co It shows the HRPES data of nanoparticles, HRPES data of O 1s and Sn 3d as Co dopant increases to 1 mol% (top), 3 mol% (middle), and 5 mol% (bottom), Co 2p HRPES data (top right) and Co dopant is 1 mol% (black), 3 mol% (red), 5 mol% (blue) HRPES data (bottom right) is a diagram showing the increase .

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In the present invention, terms such as “comprises” or “have” are intended to indicate that there are features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

In addition, the accompanying drawings in the present invention should be understood to be shown enlarged or reduced for convenience of description.

Nanoparticles

The present invention, in one embodiment, a transition metal; And antimony-tin oxide (AT0), wherein the transition metal provides nanoparticles doped on the oxide surface.

In the present application, the term "transition metal" refers to an element in which the d-shell of the outermost portion of the electron arrangement of atoms makes an incomplete cation.

If the transition metal is capable of doping the surface of the antimony-tin oxide, it may be any one of the transition metals of elements 4 to 7 and 3 to 12 in the periodic table, and specifically, the transition metal is chromium (Cr). , Manganese (Mn), iron (Fe), and cobalt (Co). For example, the transition metal may be a low-cost four-cycle transition metal, and accordingly, may have high utility in economical aspects.

In this application, the term "antimony-tin oxide" refers to tin oxide doped with antimony, and the term "doping" refers to adding a trace amount of another substance (ie, dopant) to the material to improve properties.

That is, the present invention can improve the catalytic activity of the antimony-tin oxide by doping the surface of the antimony-tin oxide using a transition metal as a dopant.

The nanoparticles may include 0.33 to 3.76 parts by weight of the transition metal, or 0.99 to 1.88 parts by weight based on 100 parts by weight of antimony-tin oxide.

The term "parts by weight" in the present application means a relative value in which a certain substance weight is converted to 1, and another substance weight is calculated based on the weight.

By including the transition metal having the content in the above range in the nanoparticle, there is an advantage that the catalyst efficiency is maximized through an increase in catalytic efficiency caused by a difference in electronegativity between a doped metal and a nanoparticle metal and generation of oxygen defect sites. On the other hand, when the transition metal is less than 0.33 parts by weight based on 100 parts by weight of the antimony-tin oxide, the nanoparticles may have less surface distribution of the transition metal particles, resulting in lower generation of catalytic activity points, and when the amount exceeds 3.76 parts by weight The catalytic activity may also be lowered due to the mutual interference between particles. Therefore, the nanoparticles may include transition metals in the above range. For example, nanoparticles may include 0.99 to 1.88 parts by weight of transition metal based on 100 parts by weight of antimony-tin oxide.

The nanoparticles may have an average diameter of 15 nm or less, specifically 2 to 15 nm or 4 to 12 nm. The average diameter of the nanoparticles satisfies the above range, thereby increasing the catalyst efficiency and maximizing the surface area to weight, thereby improving the economic efficiency.

electrode

In addition, the present invention, in one embodiment, provides an electrode comprising a mixture of the nanoparticles and a solid electrolyte.

Since the structure and components of the electrode are known to those skilled in the art to which the present invention pertains, detailed descriptions thereof will be omitted below.

For the structure and components of the electrode, the contents known to those skilled in the art to which the invention pertains are incorporated into the contents of the invention.

The type of the solid electrolyte is not particularly limited, but may be specifically Nafion.

sensor

In addition, the present invention, in one embodiment, provides a sensor including the electrode.

Since the structure and components of the sensor are known to those skilled in the art to which the present invention pertains, detailed descriptions thereof will be omitted below.

For the structure and components of the sensor, the contents known to those skilled in the art to which the invention pertains are incorporated into the contents of the invention.

The sensor may be for detecting biological material. In this application, the term "biological material" is a material that plays a role of tissue or organ or biological function of a living body using metal, ceramic, or composite material derived from nature or which can be synthesized in a laboratory by a metal component and a chemical method. Means

The biomaterial may be any one of cysteine, dopamine, and glucose.

Hereinafter, the present invention will be described in more detail by examples and experimental examples.

However, the following examples and experimental examples are merely illustrative of the present invention, and the contents of the present invention are not limited to the following examples and experimental examples.

Ingredient preparation

Chromium nitrate/hexahydrate as a dopant (Cr(NO3) ₃ , 9H ₂ O, 99%), manganese nitrate/x hydrate (Mn(NO ₃ ) ₂ , xH ₂ O, 98%), iron nitrate/hexahydrate (Fe (NO ₃ ) ₃ ·9H ₂ O, 98%) and cobalt nitrate hexahydrate (Co(NO ₃ ) ₂ ·6H ₂ O, ≥98%) were used, and these were purchased from Sigma Aldrich.

L-cysteine (Cys, 97% purity) and Nafion (5% by weight) were purchased from Sigma-Aldrich, and PBS was purchased from Gibco.

Synthesis Example 1. Synthesis of precursor solution

The precursor solution was prepared by performing one-pot synthesis.

Specifically, 10 mmol of 2-methoxyethanol (≥ 99.9%) in 10 mmol of tin chloride/pentahydrate (SnCl ₄ ·5H ₂ O, 98%, 3.505 g) and 0.5 mmol of antimony (III) chloride (SbCl ₃ ,> 99.0%, 0.114055 g).

The dopant (M) is added with 0.52 mmol of chromium nitrate hexahydrate (Cr(NO ₃ ) ₃ ·9H ₂ O, 0.292 g) so that the molar fraction of the metal dopant is 5 mol% according to the following general formula, 10 The precursor solution was prepared by stirring for a minute.

[general meal]

(Number of moles of transition metal)/((number of moles of transition metal) + (number of moles of tin))

Synthesis Example 2. Synthesis of precursor solution

A precursor solution was prepared in the same manner as in Synthesis Example 1, except that manganese nitrate·trihydrate (Mn(NO ₃ ) ₂ ·3H ₂ O, 0.121 g) was added so that the mole fraction was 5 mol%.

Synthesis Example 3. Synthesis of precursor solution

A precursor solution was prepared in the same manner as in Synthesis Example 1, except that iron nitrate·9 hydrate (Fe(NO ₃ ) ₃ ·9H ₂ O, 98%, 0.210 g) was added to be 5 mol%.

Synthesis Example 4. Synthesis of precursor solution

A precursor solution was prepared in the same manner as in Synthesis Example 1, except that cobalt nitrate•hexahydrate (Co(NO ₃ ) ₂ ·6H ₂ O, 0.151 g) was added so as to be 5 mol%.

Production Example 1. Preparation of ATO nanoparticles doped with chromium (Cr)

The precursor solution according to Synthesis Example 1 was placed in an Al ₂ O ₃ crucible, and then heat-treated at 800° C. for 5 hours (Annealing) to prepare Cr-doped ATO nanoparticles (average diameter: about 4 to 7 nm) (Cr -SnO ₂ ).

Preparation Example 2 Preparation of ATO nanoparticles doped with manganese (Mn)

The precursor solution according to Synthesis Example 2 was placed in an Al ₂ O ₃ crucible, and then heat-treated at 800° C. for 5 hours to prepare Mn-doped ATO nanoparticles (average diameter: about 5 to 7 nm) (Mn-SnO ₂₎ ).

Preparation Example 3. Preparation of ATO nanoparticles doped with iron (Fe)

The precursor solution according to Synthesis Example 3 was placed in an Al ₂ O ₃ crucible, and then heat-treated at 800° C. for 5 hours to prepare Fe-doped ATO nanoparticles (average diameter: about 6 to 9 nm) (Fe-SnO ₂ ).

Production Example 4. Preparation of ATO nanoparticles doped with cobalt (Co)

The precursor solution according to Synthesis Example 4 was placed in an Al ₂ O ₃ crucible, and then heat-treated at 800° C. for 5 hours to prepare ATO nanoparticles (average diameter: about 8 to 11 nm) doped with Co (Co-SnO _{2 ).} ).

Example 1. Preparation of Cr-doped ATO nanoparticles and Nafion-modified glass carbon electrode

After dispersing 4.0 mg of Cr-doped ATO nanoparticles according to Preparation Example 1 into 1.0 ml of distilled water containing 50 μl of Nafion, 10 minutes through an ultrasonicator (Wise cleaner, DAIHAN Sci., Wonju, Korea) During mixing, a uniform Cr-doped ATO nanoparticle-Nafion mixture was obtained.

Then, 20 µl of the mixture was placed on a glass carbon electrode (GCE) and dried in a preheated oven for 30 minutes at 75° C., where the Cr-doped ATO nanoparticles and Nafion mixture were modified glass carbon electrodes. Was produced.

Example 2. Preparation of Mn-doped ATO nanoparticles and Nafion-modified glass carbon electrode

A glass carbon electrode in which Mn-doped ATO nanoparticles and a Nafion mixture were modified under the same conditions as in Example 1 was manufactured, except that Mn-doped ATO nanoparticles according to Preparation Example 2 were used.

Example 3. Preparation of Fe-doped ATO nanoparticles and Nafion-modified glass carbon electrode

A glass carbon electrode in which the mixture of Fe-doped ATO nanoparticles and Nafion was modified was prepared under the same conditions as in Example 1, except that Fe-doped ATO nanoparticles according to Preparation Example 3 were used.

Example 4. Preparation of Co-doped ATO nanoparticles and Nafion-modified glass carbon electrode

A glass carbon electrode in which a mixture of Co-doped ATO nanoparticles and Nafion was modified was prepared under the same conditions as in Example 1, except that Co-doped ATO nanoparticles according to Preparation Example 4 were used.

Experimental Example 1. Morphology analysis of ATO nanoparticles doped with transition metal

1. TEM and XRD measurements

To analyze the morphology of nanoparticles according to Preparation Examples 1 to 4, TEM (FEI Tecnai G ² F30 S-Twin) analysis was performed at an accelerated voltage of 300 kV, and XRD (using Ni-filtered radiation) was also used. Rigaku D/Max-A diffractometer) analysis was performed.

Specifically, the size distribution and shape of the nanoparticles according to Preparation Examples 1 to 4 were analyzed through TEM analysis. Referring to the TEM image, most of the nanoparticles according to Preparation Examples 1 to 4 were 5 nm to 9 It has an average diameter between nm and was confirmed to be a very fine structure (see FIG. 1).

In addition, XRD analysis of the nanoparticles according to Preparation Examples 4 was performed, and all diffraction peaks in the XRD spectrum were (110), (101), (200), () assigned to tin (Cassiterite, SnO ₂ ). 211), (310), (112) and (202) corresponded to the 2θ = 26.8 °, 34.1 °, 38.2 °, 52.0 °, 62.2 °, 65.2 ° and 71.6 ° peaks corresponding to the reflection (JCPDS card No. 41 -1455).

Through the TEM image and the XRD pattern, the nanoparticles according to Preparation Examples 1 to 4 confirmed formation of single-phase tin oxide (SnO ₂ ), which was transferred to ATO nanoparticles without phase separation and isolation. It was confirmed that the metal was successfully doped.

2. STXM measurement

In order to analyze the shape of the nanoparticles according to Preparation Examples 1 to 4, scanning transmission X-ray microscopy (hereinafter referred to as'STXM', 10 A beamline, Pohang Accelerator Laboratory) was performed.

Specifically, STXM analysis, using a Fresnel zone plate (FZP) having an outermost zone width of 25 nm, nanoparticles according to Preparation Examples 1 to 4 on a TEM grid The X-ray was focused.

ATO nanoparticles are synthesized by a hydrothermal synthesis method, and in order to maximize electrical conductivity, the ratio of tin and antimony is set to 100:5 and added. This helps to improve the electrical conductivity in SEM and HRPES measurements, and to improve the catalyst performance by shallowening the minimum conduction band, and ATO is achieved by the main contribution of Sn ⁵⁺ at less than 22 mol% of the antimony atom The lowest resistivity can be achieved by mold doping.

However, when 3.8 mol% of Sb was included in the tin oxide (SnO ₂ ) matrix, the Sb ³⁺ state did not appear, which means that the hole transport effect can be excluded.

This structural design can achieve the catalytic effect by electrons by fixing the main carrier component.

In addition, it is possible to evaluate the photocatalytic activity through UV absorption.

Specifically, when the Sb concentration was increased to 2 mol% or more, the band gap of tin oxide (SnO ₂ ) was reduced from 3.95 eV to 3.65 eV, and it was confirmed that the UV wavelength can be actively absorbed.

In addition, in the nanoparticles according to Preparation Examples 1 to 4, in order to extract the transition metal L-edge, Sn M-edge and O K-edge spectra, X-ray absorption spectroscopy (XAS) ') was used to collect the image stacks.

HRPES analysis was performed with an electronic analyzer (Physical Electronics, PHI-3057, 8A1 beamline) at the Pohang Accelerator Laboratory (PAL).

The binding energy of the core-level spectrum was determined for the binding energy of the Au 4 f core level (E _B = 84.0 eV) for the same photon energy.

Figure 2 shows the X-ray absorption spectrum (XAS) of the nanoparticles according to Preparation Examples 1 to 4, and the corresponding lamination image.

Specifically, in the spectrum of Sn M _4,5 -edge showing the transition from the Sn ⁴⁺ 3d state to the Unoccupied p state, the SnM ₅ (3d _5/2 And 3d _3/2 ), properties between 490 eV and 497 eV and properties between 498 eV and 502 eV were observed, and Sn M-edge measurements of nanoparticles according to Preparation Examples 1 to 4 Appeared very similar.

However, the O K-edge spectral region of the nanoparticles according to Preparation Examples 1 to 4 showed very different trends.

Specifically, as can be seen in the O K-edge region, peaks were observed at 533 eV and 536 to 540 eV, 533 eV represents an empty p state in the O 1s state, and 536 to 540 eV are O in the O 2p state. 2p-Sn 5p Hybrid orbital state.

The shape and strength of the O K-edge peak for Cr-doped ATO nanoparticles according to Preparation Example 1 were very similar to those of the nanoparticles according to Preparation Example 2 and ATO nanoparticles without transition metal doping.

However, O of the nanoparticles according to Preparation Example 3 (Fe-doped ATO nanoparticles) and Preparation Example 4 (Co-doped ATO nanoparticles) K-edge is due to Fe and Co dopants, resulting in pure ATO nanoparticles O It exhibited more hybrid orbitals (536 to 540 eV) than the 2p transition (533 eV), and the orbitals of Fe and Co dopants hybridized with the O 2p orbitals according to the spectrum respectively.

The oxidation state of the transition metal dopant was determined by the metal L-edge.

Specifically, in the case of Cr-doped ATO nanoparticles according to Preparation Example 1, peaks at 576.0 eV and 577.0 eV with a shoulder at 578.4 eV were observed, which corresponded to Cr ³⁺ L ₃ -edge. .

In addition, in the case of ATO nanoparticles doped with Mn according to Preparation Example 2, a 639.2eV peak (Sharp peak) having properties at 640.7 eV was observed, which corresponded to Mn ²⁺ L ₃ -edge.

In addition, in the case of Fe-doped ATO nanoparticles according to Preparation Example 3, a 708.5 eV peak having a characteristic at 706.6 eV (Sharp peak) was observed, which corresponded to Fe ₃ ⁺ L ₃ -edge.

In addition, in the case of ATO nanoparticles doped with Co according to Preparation Example 4, doublets were identified at 776.8 eV and 777.6 eV, which were clearly distinguished from other doublets at 791.2 eV and 792.0 eV, and 776.8 eV and 777.6. The eV peaks corresponded to Co ³⁺ L ₃ -edge and Co ³⁺ L ₂ -edge, respectively.

By performing STXM measurement, among the nanoparticles according to Production Examples 1 to 4, nanoparticles and production according to Production Example 1 (Cr-doped ATO nanoparticles) and Production Example 2 (Mn-doped ATO nanoparticles) It was confirmed that the nanoparticles according to Example 3 (Fe-doped ATO nanoparticles) and Preparation Example 4 (Co-doped ATO nanoparticles) can be distinguished.

Experimental Example 2. Analysis of electrochemical properties

Evaluation of the electrochemical properties of the glass carbon electrodes according to Examples 1 to 4 was performed using a CHI617B constant potential (CH Instruments, Austin, TX) with a three-electrode cell placed in a Faraday cage.

GCE (diameter: 2 mm), platinum wire (diameter: 0.5 mm) and Ag/AgCl (3 M KCl) were used as the working electrode, counter electrode and reference electrode constituting the 3-electrode cell, respectively.

Before using the working electrode, it was polished with alumina (0.05 μm) paste on a fine cloth pad (BBuehler, Lake Bluff, IL).

Specifically, after measuring the electrochemical reaction of Cys and the glass carbon electrodes according to Examples 1 to 4, the activity of nanoparticles according to Production Examples 1 to 4 was compared.

The current value at 0.7 V was selected to compare the activity of the nanoparticles according to Preparation Examples 1 to 4.

1. Evaluation of the electrochemical oxidation-reduction reaction in the aqueous phase

The CV curve of the glass carbon electrodes according to Examples 1 to 4 was obtained by irradiating 365 nm wavelength UV light to a PBS solution containing 10 mM Cys.

Referring to FIG. 3, a pure glass carbon electrode (control), a sluggish oxidation current was observed due to the electrochemical oxidation of Cys, which is essentially slow.

In order to increase the current associated with the electrochemical oxidation of Cys, a glass carbon electrode (Examples 1 to 4) modified with a nanoparticle-nafion mixture according to Preparation Examples 1 to 4 was used, and the results were obtained. It is shown in FIG. 4.

Specifically, when the glass carbon electrodes according to Examples 1 and 2 were used, the currents associated with oxidation of Cys were measured to be 14.2 (± 1.7) μA and 10.5 (± 1.6) μA, respectively, which was Preparation Example 1 (Cr-doped ATO nanoparticles) and a nanocarbon-nafion mixture according to Preparation Example 2 (Mn-doped ATO nanoparticles) increased 7.1-fold and 5.2-fold compared to an unmodified glass carbon electrode (control, current: 2.0 μA). 4e).

In addition, the current when using the glass carbon electrodes according to Examples 3 and 4 was measured to be 3.4 (± 1.1) μA and 3.1 (± 0.6) μA, respectively, which is Preparation Example 3 (Fe-doped ATO nanoparticles). And a glass carbon electrode (control, current: 2.0 μA), which was not modified with the nanoparticle-nafion mixture according to Preparation Example 4 (Co-doped ATO nanoparticles), and increased 1.7-fold and 1.5-fold.

These results can promote the oxidation reaction of Cys even when a small amount (5 mol%) of doped metal is used, and the electrochemical oxidation current is greatly increased, especially when Cr and Mn are used as dopants according to Examples 1 and 2. Was confirmed.

2. Cys photocatalytic oxidation evaluation

The surface-sensitive S 2p core level HRPES spectrum was obtained from the results of exposing Cys (180 ℓ) to UV light having a wavelength of 365 nm and oxygen actually used in the glass carbon electrodes according to Examples 1 to 4 (FIG. 5A to 5d).

5A to 5D, distinct 2p _3/2 peaks were observed at h 161.5 eV, 162.9 eV and 168.6 eV, which are thiol groups (denoted by -SH, S1), binding status (denoted by S2), And sulfonic acid groups (SO ₃ H, indicated by S3).

Since sulfonic acid appeared as an oxidation product of the thiol group, the oxidation of Cys was monitored by measuring the ratio of the intensity of S1 to the intensity of S3 for each of the nanoparticles according to Preparation Examples 1 to 4.

Through the measurement results, it was confirmed that the nanoparticles according to Production Example 1 (Cr-doped ATO nanoparticles) and Production Example 2 (Mn-doped ATO nanoparticles) are effective catalysts (see FIGS. 5A to 5D ).

The effect of transition metal doping on the catalytic performance was confirmed by determining the ratio of S3 to S1 for a 5 mol% dopant concentration (see FIG. 5E).

In particular, the nanoparticles according to Preparation Example 1 (ATO nanoparticles doped with Cr) and Preparation Example 2 (ATO nanoparticles doped with Mn) clearly improved photocatalytic activity, and the results closely correlate with EC results. .

At various transition metal doping concentrations, a catalytic activity standard test for converting carbon monoxide (CO) to carbon dioxide (CO ₂ ) was performed to clarify the trend of catalytic activity for nanoparticles according to Preparation Examples 1 to 4 (FIG. 6).

Hiden RC 301 (mass range approx. 300 amu) system operating in cationic mode, mass spectrometry by detecting carbon monoxide (CO), oxygen (O ₂ ) and carbon dioxide (CO ₂ ) gas intensities under ultra-high vacuum conditions Was performed.

Specifically, oxidation of carbon monoxide (CO) to carbon dioxide (CO ₂ ) was monitored through a glass carbon electrode according to Examples 1 to 4 using mass spectrometry for various substrate temperatures ranging from 300K to 450K under UV irradiation. .

Specifically, at 300 K, carbon monoxide (CO) and oxygen (O ₂ ) were exposed to the glass carbon electrodes according to Examples 1 to 4 for 30 minutes (15 scans), followed by carbon dioxide (CO) in carbon monoxide (CO). The conversion to ₂ ) was evaluated (see FIGS. 6A-6D ).

6A to 6D, the conversion rate of carbon monoxide (CO) to carbon dioxide (CO ₂ ) was higher in the glass carbon electrodes according to Examples 1 and 2 as expected.

Through characterization of the catalytic oxidation reaction for the nanoparticles according to the electronic structure and Preparation Examples 1 to 4, it was confirmed that the electrochemical oxidation rate of Cys in aqueous solution and the catalytic oxidation rate in ultra-high vacuum conditions showed the same tendency. .

In particular, nanoparticles according to Preparation Example 1 (Cr-doped ATO nanoparticles) and Preparation Example 2 (Mn-doped ATO nanoparticles) under both high electrochemical oxidation rate and ultra-high vacuum conditions in solution have high catalytic activity. Showed.

Although the aqueous and UHV conditions showed very different measurement conditions, the same tendency was shown as above.

The above result shows that even if the doped metal is different, ATO The catalytic activity of nanoparticles suggests that they are independent of environmental conditions.

In addition, according to the O K-edge XAS region, compared with the nanoparticles according to Preparation Example 3 (Fe-doped ATO nanoparticles) and Preparation Example 4 (Co-doped ATO nanoparticles), Preparation Example 1 (Cr The doped ATO nanoparticles) and the nanoparticles according to Preparation Example 2 (Mn-doped ATO nanoparticles) show a higher proportion of lower hybrid oxygen state (533 eV) (see FIG. 2).

The doped transition metal transitions from the 3d orbital to the empty O 2p state, which can facilitate the removal of oxygen atoms from ATO nanoparticles and promote catalytic oxidation of Cys.

According to the HRPES data due to the increase in the amount of doping of the transition metal (see FIGS. 7 to 10), 531.9 eV exists in the O 1s spectrum, which is assigned as an oxygen deficient site, and is exclusively prepared in Preparation Example 1 (Cr-doped ATO nano Only the nanoparticles (see FIG. 7) according to the particles) and the nanoparticles (see FIG. 8) according to Preparation Example 2 (ATO nanoparticles doped with Mn) exhibited additional states in the valence band region.

However, since there is no relationship between the new state and catalyst performance, the reaction was not caused by hole transport.

Rational analysis of the binding sites and reactive charges confirmed that high temperature electrons could be delivered to the oxygen depletion site (electron trap site) to improve photo and electrochemical activity.

Claims (9)

Transition metals; And
Antimony-tin oxide (AT0),
The transition metal is an electrode containing a mixture of nanoparticles and a solid electrolyte that is doped on an antimony-tin oxide surface.
According to claim 1,
Transition metal,
An electrode that is any one of chromium (Cr), manganese (Mn), iron (Fe), and cobalt (Co).
According to claim 1,
Nanoparticles,
An electrode comprising 0.33 to 3.76 parts by weight of transition metal based on 100 parts by weight of antimony-tin oxide.
According to claim 1,
Nanoparticles,
An electrode having an average diameter of 15 nm or less.
delete According to claim 1,
The solid electrolyte is Nafion.
A sensor comprising the electrode according to claim 1.
The method of claim 7,
A sensor intended for biomaterial detection.
The method of claim 8,
The biological material is any one of cysteine (L-cysteine), dopamine (Dopamine) and glucose (Glucose).

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