Platinum oxide nanosheet including titanium dioxide particles and manufacturing method therefor

Abstract

The present invention relates to a platinum-substituted titanium oxide nanosheet including titanium dioxide particles and a method for manufacturing same. In addition to a platinum oxide (PtO2-x) nanosheet exhibiting excellent gas reactivity compared to existing metal oxide nanosheets, the invention provides a platinum-substituted titanium oxide nanosheet including titanium dioxide particles on the surface thereof, which exhibits enhanced reactivity to various gases such as ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (CH3COCH3) due to the titanium dioxide (TiO2) particles with excellent gas-sensing capabilities.

Description

Platinum oxide nanosheet containing titanium dioxide particles and method for producing the same

[0001] The present invention relates to a platinum oxide nanosheet comprising titanium dioxide particles and a method for preparing the same. Specifically, the present invention relates to a platinum oxide nanosheet comprising titanium dioxide particles that exhibits enhanced reactivity toward various gases, such as ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (CH3COCH3). In addition, the present invention relates to a platinum oxide nanosheet used as an anode active material for a lithium secondary battery.

[0002] Gas sensors are experiencing a surge in demand, as they can detect harmful gases early, allowing for early intervention. Accordingly, gas sensor technologies that detect harmful gases in the external environment, measure air quality, and monitor specific diseases by detecting trace amounts of biomarker gases in exhaled breath in real time are attracting significant attention.

[0003] Representative biomarker gases include, for example, ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (CH3COCH3). In order to manufacture a healthcare gas sensor capable of early monitoring by detecting these biomarker gases, a gas sensor with high sensitivity, high selectivity, and fast response even at low gas concentrations is required.

[0004] As a technology for detecting these gases, research on semiconductor-based metal oxide gas sensors is actively underway.

[0005] Metal oxide semiconductor-based gas sensors utilize the principle of measuring the resistance change ratio (Rair / Rgas) caused by surface adsorption-desorption chemical reactions of specific gas molecules on the surface of a metal oxide semiconductor sensing material. Therefore, they have the advantages of being relatively inexpensive, easy to fabricate a simple sensor array, miniaturization, portability, and real-time measurement.

[0006] However, in order to be utilized as a gas sensor for early monitoring healthcare that diagnoses biomarker gases, sensor performances of high sensitivity, high selectivity, and fast response even at low gas concentrations are required, but existing metal oxide gas sensors have the problem of low reactivity to gases and low ability to selectively detect specific gases.

[0007] Therefore, there is a need for the development of a sensing material for a gas sensor that can selectively detect a specific gas and exhibits excellent reactivity to overcome these problems.

[0008] Meanwhile, in lithium secondary batteries, the anode active material stores or releases lithium ions released from the cathode active material through reduction and oxidation reactions, allowing current to flow through an external circuit. This material, typically manufactured by coating graphite onto copper foil, determines the capacity, charging speed, and lifespan of electric vehicle batteries. The most essential characteristics of anode active materials are high energy capacity, long lifespan, and charge / discharge efficiency for improved charging speeds. To achieve these goals, material changes are required.

[0009] The purpose of the present invention is to solve the conventional problems, and to provide a platinum oxide (PtO) nanosheet that exhibits superior gas reactivity compared to existing metal oxide nanosheets. 2-x ) In addition to the nanosheets, the present invention provides a platinum oxide nanosheet containing titanium dioxide particles that exhibit enhanced reactivity to various gases such as ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (Acetone (CH3COCH3)) due to the titanium dioxide (TiO2) particles present on the surface having excellent gas sensing capabilities.

[0010] In addition, an object of the present invention is to provide an anode active material that exhibits improved battery characteristics compared to existing graphite anode active materials.

[0011] To achieve the above purpose,

[0012] The present invention relates to a platinum-substituted titanium oxide (Ti) having titanium dioxide (TiO2) nanoparticles formed on the surface. 1-x Ptx O 2-y ) provides nanosheets.

[0013] The size of the above titanium dioxide (TiO2) nanoparticles is preferably 20 to 80 nm.

[0014] The above platinum-substituted titanium oxide nanosheet can have a sensing ability for one or more gases selected from the group consisting of ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (CH3COCH3).

[0015] In addition, the present invention provides a gas sensor characterized by including a platinum-substituted titanium oxide nanosheet.

[0016] In addition, the present invention

[0017] (a) A step of preparing titanium dioxide (TiO2) nanosheets;

[0018] (b) a step of preparing a platinum (Pt)-based solution by mixing a platinum (Pt nitride) precursor, alcohol, and purified water (DI water);

[0019] (c) a step of mixing the titanium dioxide (TiO2) nanosheet of step (a) and the platinum (Pt)-based solution of step (b) and performing a hydrothermal synthesis process and a microwave process; a method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles is provided.

[0020] In the above step (a), the titanium dioxide (TiO2) nanosheet may be a monolayer.

[0021] In the above step (b), it is preferable that the platinum (Pt nitride) precursor is included in an amount of 0.1 to 1 part by weight, the alcohol is included in an amount of 0.1 to 1 part by weight, and the purified water (DI water) is included in an amount of 1 to 5 parts by weight.

[0022] In the above step (b), it is preferable that the platinum (Pt nitride) precursor is at least one selected from the group consisting of platinum (II) nitrate (Pt(NO3)2), platinum (II) chloride (PtCl2), platinum (IV) chloride (PtCl4), and platinum (II) acetylacetonate (Pt(C5H7O2)2).

[0023] In the above step (b), the alcohol may be 2-propanol or ethanol.

[0024] In the above step (c), it is preferable to mix the titanium dioxide (TiO2) nanosheets and the platinum (Pt)-based solution in a ratio of 3 to 5:1.

[0025] In the above step (c), it is preferable that the hydrothermal synthesis process is performed at a temperature of 60 to 120°C for 1 to 8 hours.

[0026] In the above step (c), it is preferable that the microwave process is performed at 700 W to 1000 W for 30 seconds to 5 minutes.

[0027] In the above step (c), Pt is substituted at the Ti position of the titanium dioxide (TiO2) nanosheet through a hydrothermal synthesis process to form platinum-substituted titanium oxide (Ti 1-x Pt x O 2-y ) nanosheets are synthesized.

[0028] The above substituted Ti is the above synthesized platinum substituted titanium oxide (Ti 1-x Pt x O2-y ) is formed as titanium dioxide (TiO2) particles on the surface.

[0029] In addition, a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles manufactured by the manufacturing method of the present invention is provided.

[0030] In addition, the present invention relates to a platinum-substituted titanium oxide (Ti 1-x Pt x O 2-y ) provides a negative electrode active material for a lithium secondary battery characterized by including nanosheets.

[0031] The platinum-substituted titanium oxide nanosheet of the present invention has superior gas reactivity compared to the existing TiO2 nanosheet, and contains titanium dioxide particles on the surface, so that it exhibits further enhanced reactivity to various gases such as ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (Acetone (CH3COCH3), and can have excellent gas sensing capabilities.

[0032] In addition, platinum-substituted titanium oxide nanosheets can be synthesized in a simple manner using hydrothermal synthesis and microwave processes, and the process time is significantly reduced.

[0033] Furthermore, the negative electrode active material of the present invention can exhibit fast charge / discharge speed, excellent stability, and ionic conductivity.

[0034] Figure 1 is a conventional TiO manufactured in Example 1. 2-y This is an XRD (X-ray diffraction) image showing the structure of the nanosheet.

[0035] Figure 2 is Ti of the present invention manufactured in Example 2. 1-x Ptx O 2-y This is an XRD image showing the structure of the nanosheet.

[0036] Figure 3 is a conventional TiO manufactured in Example 1. 2-y This is an XRD image showing the structure of the nanosheet and a photograph of a film made using it.

[0037] Figure 4 is Ti of the present invention manufactured in Example 2. 1-x Pt x O 2-y This is an XRD image showing the structure of the nanosheet and a photograph of a film made using it.

[0038] Figure 5 is a conventional TiO manufactured in Example 1. 2-y These are photos showing the results of TEM (Transmission Electron Microscope) and EDS (Energy-dispersive X-ray spectroscopy) analysis showing nanosheets.

[0039] Figure 6 is Ti of the present invention manufactured in Example 2. 1-x Pt x O 2-y These are TEM and EDS analysis results showing nanosheets.

[0040] Figure 7 is Ti of the present invention manufactured in Example 2. 1-x Pt x O 2-y These are TEM and EDS analysis results showing the shape and synthesis results of TiO2 particles formed on the surface of nanosheets.

[0041] Figure 8 is a conventional TiO manufactured in Example 1. 2-y Ti of the present invention manufactured by nanosheet and Example 2 1-x Pt x O 2-y This is a photograph of the XPS (X-ray photoelectron spectroscopy) analysis results for Ti 2p, which shows the composition and bonding state of the nanosheet.

[0042] Figure 9 is a conventional TiO manufactured in Example 1.2-x Ti of the present invention manufactured by nanosheet and Example 2 1-x Pt x O 2-y This is a photo of the XPS analysis results for O 1s showing the components and bonding state of the nanosheet.

[0043] Figure 10 is Ti of the present invention manufactured in Example 2. 1-x Pt x O 2-y This is a photo of the XPS analysis results for Pt showing the components and bonding state of the nanosheet.

[0044] Figure 11 is Ti of the present invention manufactured in Example 2. 1-x Pt x O 2-y The resulting images show the reactivity of nanosheets to various gases.

[0045] Figure 12 is a conventional Ti manufactured in Example 1. 1-x Pt x O 2-y The resulting images show the reactivity of nanosheets to various gases.

[0046] Figures 13 to 15 are Ti of the present invention manufactured in Example 2. 1-x Pt x O 2-y These graphs show the battery characteristics of negative electrode materials manufactured from nanosheets.

[0047] Hereinafter, the present invention will be described in detail. In describing the present invention, detailed descriptions of related known structures or functions may be omitted.

[0048] Terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted with meanings and concepts that are consistent with the technical aspects of the present invention.

[0049] The embodiments described in this specification and the configurations illustrated in the drawings are preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention, so there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0050]

[0051] The present invention relates to a platinum-substituted titanium oxide (Ti) having improved reactivity to various gases. 1-x Pt x O 2-y ) provides nanosheets.

[0052] The platinum-substituted titanium oxide (Ti) of the present invention 1-x Pt x O 2-y ) nanosheets are platinum-substituted titanium oxide (TiO2) sheets with titanium dioxide (TiO2) nanoparticles formed on the surface. 1-x Pt x O 2-y ) is a nanosheet.

[0053] The above platinum-substituted titanium oxide (Ti 1-x Pt x O 2-y ) During the process of synthesizing nanosheets, Pt ions are substituted for Ti ion sites, breaking the Ti-O bond to form Pt-O bonds, and the Ti ions that are substituted and removed react with oxygen to form TiO2 nanoparticles that are decorated on the surface.

[0054] The size of the above titanium dioxide (TiO2) nanoparticles is preferably 20 to 80 nm.

[0055] If the size of the titanium dioxide (TiO2) nanoparticles exceeds the above range, the particles may become heavy and have difficulty sticking to the sheet, and if it falls below the above range, the particles may not react well with gas.

[0056] The above platinum-substituted titanium oxide (Ti 1-x Pt x O2-y ) The nanosheet may have a sensing ability for one or more gases selected from the group consisting of ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (CH3COCH3).

[0057] In addition, the present invention relates to a platinum-substituted titanium oxide (Ti 1-x Pt x O 2-y ) provides a gas sensor characterized by including a nanosheet.

[0058] In addition, the present invention

[0059] (a) A step of preparing titanium dioxide (TiO2) nanosheets;

[0060] (b) a step of preparing a platinum (Pt)-based solution by mixing a platinum (Pt nitride) precursor, alcohol, and purified water (DI water);

[0061] (c) a step of mixing the titanium dioxide (TiO2) nanosheet of step (a) and the platinum (Pt)-based solution of step (b) and performing a hydrothermal synthesis process and a microwave process; a platinum-substituted titanium oxide (Ti) containing titanium dioxide nanoparticles characterized by including 1-x Pt x O 2-y ) provides a method for manufacturing a nanosheet.

[0062] In the above step (a), the titanium dioxide (TiO2) nanosheet may be a monolayer.

[0063] In the above step (b), it is preferable that the platinum (Pt nitride) precursor is included in an amount of 0.1 to 1 part by weight, the alcohol is included in an amount of 0.1 to 1 part by weight, and the purified water (DI water) is included in an amount of 1 to 5 parts by weight.

[0064] If the weight of the above platinum (Pt nitride) precursor exceeds the above range, aggregation of platinum nanoparticles may occur, resulting in poor substitution, or the presence of ions that are sufficiently substituted but remain, resulting in waste. If it falls below the above range, the entire substitution may not occur, resulting in partial PtO. 2-x Problems may arise when creating nanosheets.

[0065] If the weight of the alcohol exceeds the above range, problems such as wastage of alcohol may occur because no change occurs even if more is added, and if it falls below the above range, problems such as the platinum precursor not being sufficiently dissolved may occur.

[0066] If the weight of the purified water exceeds the above range, problems such as waste of purified water may occur because no change will occur even if more is added, and if it falls below the above range, problems such as the platinum precursor not being sufficiently dissolved may occur.

[0067] In the above step (b), the platinum (Pt nitride) precursor is preferably at least one selected from the group consisting of platinum (II) nitrate (Pt(NO3)2), platinum (II) chloride (PtCl2), platinum (IV) chloride (PtCl4), and platinum (II) acetylacetonate (Pt(C5H7O2)2), but is not limited thereto, and any platinum precursor commonly used can be used.

[0068] In the above step (b), the alcohol may be 2-propanol or ethanol.

[0069] In the above step (c), it is preferable to mix the titanium dioxide (TiO2) nanosheets and the platinum (Pt)-based solution in a ratio of 3 to 5:1.

[0070] In the above step (c), it is preferable that the hydrothermal synthesis process is performed at a temperature of 60 to 120°C for 1 to 8 hours.

[0071] When the above temperature exceeds the above range, the base material is TiO 2-y Ti due to deformation of nanosheets 1-x Pt x O 2-y A problem may arise in which nanosheets are not synthesized, and if the above range is not met, a problem in which the entire ring is not formed due to insufficient energy for Pt ions to be substituted for Ti ions may arise.

[0072] If the above time exceeds the above range, Ti due to long time 1-x Pt x O 2-y Problems such as bonding and size coarsening between nanosheets may occur, and if the above range is not met, problems may arise in which the overall reaction does not occur evenly.

[0073] In the above step (c), it is preferable that the microwave process is performed at 700 W to 1000 W for 30 seconds to 5 minutes.

[0074] If the above wattage (W) exceeds the above range, the base material is TiO 2-y Ti due to deformation of nanosheets 1-x Pt x O 2-yA problem may arise in which nanosheets are not synthesized, and if the above range is not met, a problem may arise in which the entire ring is not formed because the energy is insufficient for the Pt ion to be substituted for the Ti ion.

[0075] If the above time exceeds the above range, Ti due to long time 1-x Pt x O 2-y Problems such as bonding and size coarsening between nanosheets may occur, and if the above range is not met, problems may arise in which the overall reaction does not occur evenly.

[0076] In the above step (c), Pt is substituted at the Ti position of the titanium dioxide (TiO2) nanosheet through a hydrothermal synthesis process to form platinum-platinum-substituted titanium oxide (Ti 1-x Pt x O 2-y ) nanosheets are synthesized.

[0077] In the prior art, there is no example of manufacturing a noble metal oxide using a general metal oxide as in the present invention, and the conventional method of manufacturing platinum oxide nanosheets is complex and time-consuming. However, the present invention utilizes a heterogeneous element as a catalyst material and is manufactured through hydrothermal synthesis and microwave processes, thereby offering the advantages of simplicity and a short process time. In addition, it is characterized by being manufactured in a unique oxide form called a nanosheet.

[0078] Additionally, it exhibits high gas reactivity compared to the base material, titanium dioxide (TiO2) nanosheets.

[0079] The above substituted Ti is the above synthesized platinum substituted titanium oxide (Ti 1-x Pt x O 2-y ) is formed as titanium dioxide (TiO2) particles on the surface of the nanosheet.

[0080] The above titanium dioxide (TiO2) particles are used as a gas sensor or catalyst, and these titanium dioxide (TiO2) particles are substituted with platinum-substituted titanium oxide (Ti 1-x Pt x O 2-y ) By existing on the surface of the nanosheet, platinum oxide and titanium dioxide can have a synergistic effect and exhibit high reactivity toward gas.

[0081] In addition, platinum-substituted titanium oxide (Ti) containing titanium dioxide nanoparticles manufactured by the manufacturing method of the present invention 1-x Pt x O 2-y ) provides nanosheets.

[0082]

[0083] Hereinafter, the present invention will be described in more detail through examples. These examples are intended solely to illustrate the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples, in accordance with the gist of the present invention.

[0084]

[0085] Example 1 TiO 2-x Manufacturing of nanosheets

[0086] K through the flux method 0.8 Ti 1.73 Li 0.27 After synthesizing the O4(KTLO) single crystal material, it was acid-treated for 5 days using hydrochloric acid (HCl) with a concentration of 0.5 M to obtain H 1.07 Ti 1.73 O4·H2O(HTO) material was manufactured.

[0087] The above HTO material was chemically exfoliated using a TBAOH (tetrabutylammonium hydroxide) solution for 14 days to finally form a monolayer of TiO. 2-y Nanosheets (in the form of a colloidal solution) were prepared.

[0088]

[0089] Example 2 Ti 1-x Pt x O 2-y Manufacturing of nanosheets

[0090] Platinum (Pt nitride) precursor (Pt(NO3)2) 0.15 g, 2-propanol 0.18 g, and purified water (DI water) 2.82 g were placed in a beaker and stirred at room temperature using a magnetic bar to prepare a base solution.

[0091] TiO prepared in Example 1 2-y Nanosheets were mixed with the above-mentioned base solution in a 4:1 ratio, placed in a Teflon container, and hydrothermally synthesized at 70°C for 4 hours, and a microwave process was performed at 1000 W for 2 minutes to substitute Pt at the Ti position, and the substituted Ti was replaced with platinum-substituted titanium oxide (Ti) existing as TiO2 particles on the surface. 1-x Pt x O 2-y ) nanosheets were manufactured.

[0092]

[0093] Evaluation Example 1 XRD Analysis

[0094] Conventional TiO prepared in Example 1 2-x Ti of the present invention manufactured by nanosheet and Example 2 1-x Pt x O 2-y To confirm the structure of the nanosheet, XRD (X-ray diffraction) analysis was performed.

[0095] Referring to Figures 1 and 2, the results measured through film-only XRD show that TiO 2-y Nanosheet, Ti 1-x Pt x O 2-yIt can be seen that all nanosheets have sheet-like XRD peaks measured, and it can be seen that even when Pt ions are substituted for Ti ions, the structure of the nanosheets does not collapse and the shape of the nanosheets is maintained.

[0096] Also, referring to Figures 3 and 4, it can be confirmed that a film is made through an AAO filter. Through this, Ti manufactured in Example 2 1-x Pt x O 2-y It can be seen that the nanosheets maintain their shape.

[0097]

[0098] Evaluation Example 2 TEM and EDS Analysis

[0099] Conventional TiO prepared in Example 1 2-y Ti of the present invention manufactured by nanosheet and Example 2 1-x Pt x O 2-y To confirm the shape and synthesis results of the nanosheet and the TiO2 particles formed on its surface, TEM (Transmission Electron Microscope) and EDS (Energy-dispersive X-ray spectroscopy) analyses were performed.

[0100] Referring to Fig. 5, TiO 2-y It can be seen that nanosheets have been formed.

[0101] Referring to Fig. 6, Ti 1-x Pt x O 2-y TEM images of the nanosheets confirm that Pt ions exist within the nanosheet lattice, and that nanopores are formed as Pt is substituted.

[0102] Also, referring to Fig. 7, Ti 1-x Pt x O 2-yNanoparticles exist on the surface of the nanosheet, and when EDS analysis was performed, it was confirmed that they were TiO2 nanoparticles, and Ti 1-x Pt x O 2-y It can be seen that the nanosheets are showing a shape that holds the particles.

[0103]

[0104] Evaluation Example 3 XPS Analysis

[0105] Conventional TiO prepared in Example 1 2-y Ti of the present invention manufactured by nanosheet and Example 2 1-x Pt x O 2-y To confirm the composition and bonding state of the nanosheet, XPS (X-ray photoelectron spectroscopy) analysis was performed.

[0106] Referring to Fig. 8, TiO 2-y Nanosheets and Ti 1-x Pt x O 2-y XPS analysis results for nanosheets showed that TiO 2-y Nanosheets are Ti 1-x Pt x O 2-y By changing to nanosheets, it was confirmed that the Ti binding was noticeably reduced in the case of the Ti 2p peak, which means that Pt ions were substituted for Ti ion sites.

[0107] Referring to Fig. 9, it can be confirmed that the oxygen vacancy has noticeably increased through the O 1s peak, which is one of the parameters that has an important effect on the responsiveness of the gas sensor, and is a result proving that the responsiveness to gas has increased.

[0108] Also, referring to Fig. 10, compared to Ref, Pt 2+ , Pt 4+ It can be confirmed that the specific gravity of the present invention is high. Therefore, the Ti of the present invention manufactured in Example 2 1-x Ptx O 2-y It can be seen that in the nanosheet, Pt is likely to exist not in a metallic state but in a state of bonding with oxygen (Ti 1-x Pt x O 2-y ).

[0109]

[0110] Evaluation Example 4 Ti 1-x Pt x O 2-y Confirmation of gas reactivity of nanosheets

[0111] Ti of the present invention manufactured in Example 2 1-x Pt x O 2-y To confirm the reactivity of nanosheets to various gases, resistance changes were analyzed using gas sensor equipment. The gases tested were hydrogen sulfide (H2S), acetone (CH3COCH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), and benzene (C6H6).

[0112] Conventional TiO prepared in Example 1 2-y Referring to Figure 12 related to the nanosheet, it can be seen that the reactivity to gas is low due to differences in the oxygen vacancy of the surface that reacts with gas and the catalytic properties of the Ti and Pt elements themselves.

[0113] In contrast, referring to FIG. 11, the platinum-substituted titanium oxide (Ti) of the present invention manufactured in Example 2 1-x Pt x O 2-y) nanosheets are known to have high reactivity toward gases such as hydrogen sulfide (H2S), acetone (CH3COCH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), and benzene (C6H6) due to the increased oxygen vacancy and the catalytic properties of Pt.

[0114] Therefore, the Ti of the present invention 1-x Pt x O 2-y Nanosheets are found to have enhanced reactivity toward various gases.

[0115]

[0116] Evaluation Example 5 Ti 1-x Pt x O 2-y Confirming the battery properties of nanosheets

[0117] Ti of the present invention manufactured in Example 2 1-x Pt x O 2-y To confirm the battery characteristics of the negative electrode material manufactured from nanosheets, coin cells were manufactured and analyzed.

[0118] Referring to FIG. 13, it can be seen that the negative electrode active material according to the present invention has a small overpotential, thereby increasing the charge / discharge speed. Specifically, the overpotential may be approximately 0.08 V.

[0119] Referring to FIG. 14, it can be seen that the negative electrode active material according to the present invention has high stability, as its charge capacity is maintained even after 200 cycles. Specifically, it can have a Coulomb coefficient of up to 90.41%.

[0120] In addition, referring to FIG. 15, it can be confirmed that the negative electrode active material according to the present invention has high ionic conductivity. Specifically, the ionic conductivity can be 87 Ohm.

Claims

1. Platinum-substituted titanium oxide (TiO2) with titanium dioxide (TiO2) nanoparticles formed on the surface 1-x Pt x O 2-y ) nanosheets.

2. In paragraph 1, A platinum-substituted titanium oxide nanosheet comprising titanium dioxide nanoparticles, characterized in that the size of the titanium dioxide (TiO2) nanoparticles is 20 to 80 nm.

3. In paragraph 1, A platinum-substituted titanium oxide nanosheet comprising titanium dioxide nanoparticles characterized by having a sensing ability of at least one gas selected from the group consisting of ammonia (NH3), carbon monoxide (CO), hydrogen (H2), formaldehyde (CH2O), toluene (C7H8), benzene (C6H6), hydrogen sulfide (H2S), and acetone (CH3COCH3).

4. A gas sensor characterized by comprising a platinum-substituted titanium oxide nanosheet according to any one of claims 1 to 3. 5.(a) Step of preparing titanium dioxide (TiO2) nanosheets; (b) a step of preparing a platinum (Pt)-based solution by mixing a platinum (Pt nitride) precursor, alcohol, and purified water (DI water); (c) A method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles, characterized by comprising a step of mixing the titanium dioxide (TiO2) nanosheet of step (a) and the platinum (Pt)-based solution of step (b) and performing a hydrothermal synthesis process and a microwave process.

6. In paragraph 5, A method for producing a platinum-substituted titanium oxide nanosheet comprising titanium dioxide nanoparticles, characterized in that in the step (a) above, the titanium dioxide (TiO2) nanosheet is a monolayer.

7. In paragraph 5, A method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles, characterized in that in the step (b), the platinum (Pt nitride) precursor is contained in an amount of 0.1 to 1 part by weight, alcohol is contained in an amount of 0.1 to 1 part by weight, and purified water (DI water) is contained in an amount of 1 to 5 parts by weight.

8. In paragraph 5, A method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles, characterized in that in the step (b), the platinum (Pt nitride) precursor is at least one selected from the group consisting of platinum (II) nitrate (Pt(NO3)2), platinum (II) chloride (PtCl2), platinum (IV) chloride (PtCl4), and platinum (II) acetylacetonate (Pt(C5H7O2)2).

9. In paragraph 5, A method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles, characterized in that in the step (b) above, the alcohol is 2-propanol or ethanol.

10. In paragraph 5, A method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles, characterized in that in the step (c) above, the titanium dioxide (TiO2) nanosheet and the platinum (Pt)-based solution are mixed in a ratio of 3 to 5:

1.

11. In paragraph 5, A method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles, characterized in that in the step (c) above, the hydrothermal synthesis process is performed at a temperature of 60 to 120°C for 1 to 8 hours.

12. In paragraph 5, A method for producing a platinum-substituted titanium oxide nanosheet including titanium dioxide nanoparticles, characterized in that in the step (c) above, the microwave process is performed at 700 W to 1000 W for 30 seconds to 5 minutes.

13. In paragraph 5, In the above step (c), Pt is substituted at the Ti position of the titanium dioxide (TiO2) nanosheet through a hydrothermal synthesis process to form platinum oxide (PtO 2-x ) A method for producing a platinum-substituted titanium oxide nanosheet comprising titanium dioxide nanoparticles characterized in that nanosheets are synthesized.

14. In paragraph 13, The above substituted Ti is the above synthesized platinum oxide (PtO 2-x ) A method for producing a platinum-substituted titanium oxide nanosheet comprising titanium dioxide nanoparticles characterized in that the titanium dioxide (TiO2) particles are formed on the surface of the nanosheet.

15. A platinum-substituted titanium oxide nanosheet comprising titanium dioxide nanoparticles manufactured by a manufacturing method selected from among claims 5 to 14.

16. A negative electrode active material for a lithium secondary battery, characterized in that it comprises a platinum-substituted titanium oxide nanosheet according to any one of claims 1 to 3.

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