CoZr-LDH / RGO composite sensitive material, preparation method, gas sensitive element and application
By preparing CoZr-LDH/rGO composites, the problem of limited sensing response in thin gases is solved, and high sensitivity and stable gas sensing performance are achieved, especially in the detection of n-pentanol.
Patent Information
- Application Number
- CN202510650577.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-20
- Publication Date
- 2025-08-22
Smart Images
Figure CN120522243A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of room temperature sensitive semiconductor materials, and in particular to a CoZr-LDH / rGO composite sensitive material, a preparation method, a gas sensing element and applications. Background Art
[0002] Layered metal hydroxides are a type of two-dimensional inorganic layered material composed of positively charged metal hydroxide layers, interlayer anions and water molecules. They are usually composed of two-dimensional ultra-thin single-crystalline nanosheets with lateral dimensions ranging from tens of nanometers to several microns and thicknesses of tens of nanometers. They have the characteristics of large specific surface area, flexible composition, replaceable anions, and adjustable interlayer spacing.
[0003] Layered double hydroxides (LDHs) are known for their unique layered structure, high porosity, and large surface area, facilitating rapid gas adsorption and desorption. Recent studies have also identified LDHs as promising room-temperature gas-sensing materials with broad application prospects. However, due to their high surface charge and hydrophilicity, LDH nanosheets tend to stack. This leads to a significant reduction in porosity and surface area, hindering their application in highly sensitive sensors. Furthermore, LDHs inherently exhibit poor electrical conductivity, which severely limits their sensing response when exposed to dilute gases. Summary of the Invention
[0004] In view of the problem in the prior art that layered double hydroxides have limited sensing response when exposed to rarefied gases, the present invention provides a CoZr-LDH / rGO composite sensitive material, a preparation method, a gas sensing element and applications.
[0005] The present invention is achieved through the following technical solutions: A CoZr-LDH / rGO composite sensitive material has Zr and Co as central metal ions, a layered crystal structure with a bimetallic central skeleton, and anionic groups between layers of the layered crystal structure, wherein the anionic groups include hydroxide ions, nitrate ions, and fluoride ions.
[0006] A method for preparing the CoZr-LDH / rGO composite sensitive material as described above comprises the following steps: Step 1, using isopropyl alcohol aqueous solution as solvent to prepare 2+ 、Zr 4+ Solution A and solution B; Step 2, slowly adding solution B dropwise to solution A and stirring to obtain solution C; Step 3, adding ammonium fluoride to solution C and stirring to obtain solution D; Step 4, adding urea to solution D and stirring to obtain solution E; Step 5, adding graphene oxide rGO to solution E and stirring evenly to obtain a precursor solution F; Step 6: The precursor solution F is subjected to an aging reaction, and then cooled, centrifuged, washed and dried to obtain a CoZr-LDH / rGO composite sensitive powder material.
[0007] Preferably, in step 1, the isopropanol aqueous solution is prepared by mixing analytically pure isopropanol and deionized water in a volume ratio of 1:(0.5-2.0) to obtain the isopropanol aqueous solution; Co in solution A 2+ The concentration is 1.0 mmol·L -1 ; Zr in solution B 4+ The concentration is 5.0 mmol·L -1 .
[0008] Preferably, in step 2, the molar ratio of Co element to Zr element in solution C is 1:(0.2~5.0).
[0009] Preferably, in step 3, F in solution D - The concentration is 1~10 mmol·L -1 .
[0010] Preferably, in step 4, the pH value of solution E is 2-6.
[0011] Preferably, in step 5, the amount of graphene oxide rGO added is 0.1 wt% to 5 wt% of the total mass of the metal salts in solution E.
[0012] Preferably, in step 6, during the aging reaction, the temperature is 90-180° C. and the time is 8-20 h; When cooling, use furnace cooling to room temperature; After centrifugation, the precipitate was washed with deionized water and ethanol respectively; When drying, the temperature is 50~80℃ and the time is 10~40 hours.
[0013] A gas sensor comprising the CoZr-LDH / rGO composite sensitive material.
[0014] Application of the CoZr-LDH / rGO composite sensitive material in the detection of n-pentanol at room temperature.
[0015] Compared with the prior art, the present invention has the following beneficial effects: The CoZr-LDH / rGO composite sensitive material, based on Zr and Co as central metal ions, possesses a layered crystal structure with a bimetallic core skeleton. The concentration, valence, and distribution of Co and Zr ions can be varied and flexibly controlled, resulting in a dual-ion synergistic catalytic sensitivity effect. The layered crystal structure is rich in anionic groups such as hydroxide, nitrate, and fluoride, resulting in adjustable interlayer spacing and excellent selective adsorption.
[0016] The reduced graphene oxide in the composite material has a large specific surface area, good chemical stability, and excellent electronic conductivity. It exhibits high sensitivity, rapid response, and recovery to n-pentanol molecules at room temperature. Furthermore, the reduced graphene oxide surface contains a small number of defects and oxygen-containing functional groups, which contribute to the material's selective adsorption and sensitive response. Graphene is a typical two-dimensional material with a large surface area, good chemical stability, and excellent electron mobility. Graphene oxide (GO), obtained by further oxidation of graphene, contains numerous defect sites and functional groups, making GO a suitable structure-directing agent for the growth of certain nanoparticles. The composite material of LDH and reduced graphene oxide combines the excellent physical and chemical properties of both LDH and graphene, while overcoming the poor conductivity and easy aggregation of graphene sheets associated with LDH. The gas-sensing advantages of the reduced graphene oxide / LDH composite material are its high sensitivity, high selectivity, good stability, low operating temperature, and excellent electron mobility. These properties make this material promising for broad application in gas sensors, particularly in electrochemical energy storage and conversion.
[0017] The present invention discloses a method for preparing a CoZr-LDH / rGO composite sensitive material. Co(NO3)2·6H2O and Zr(NO3)4·5H2O are used as raw materials. The two metal salts are dissolved in an isopropanol aqueous solution. The volume ratio of isopropanol to water is precisely controlled to control the supersaturation of the raw materials, thereby influencing the nucleation and growth of the LDH material during the hydrothermal reaction. Urea is used to adjust the pH value of the solution and the valence state of the metal ions. Ammonium fluoride is selected as an ionic intercalation agent to regulate the interlayer spacing and the arrangement of anions between the layers of the CoZr-LDH, altering the electrostatic field between the layers and promoting the selective adsorption and diffusion of target gas molecules. GO is added to a precursor solution at a specific concentration ratio. Hydrothermal treatment is performed to control the thermal reduction process to produce rGO. Simultaneously, the pH value of the precursor is adjusted to control the hydrolysis and reaction degree of the metal salts, promoting the growth of the CoZr-LDH / rGO heterogeneous interface and the formation of the target material. This method has low preparation cost, easy operation, and strong controllability. It can effectively improve the adsorption and sensitivity effect of the material to target gas molecules, reduce the activation energy of the material's sensitivity, and achieve room temperature sensitivity.
[0018] This preparation method can achieve controllable material composition, regulation of interlayer metal ion valence and defect distribution, and obtain materials with specific particle size and morphology. The sensitivity of the obtained product is mainly controlled by the following factors: raw material concentration and ratio, medium pH value, solvent type, ratio of isopropyl alcohol to water, amount of ammonium fluoride, amount of graphene oxide, amount of urea and hydrothermal treatment process. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a flow chart of a method for preparing a CoZr-LDH / RGO composite sensitive material according to the present invention; Figure 2 1 is the XRD pattern of the CoZr-LDH / rGO composite sensitive material prepared in Examples 1 to 5 of the present invention.
[0020] Figure 3 These are scanning electron microscope images of the CoZr-LDH / rGO composite sensitive materials prepared in Examples 1 to 5 of the present invention.
[0021] Figure 4 This is a working temperature diagram of the CoZr-LDH / rGO composite sensitive material prepared in Examples 1 to 5 of the present invention to 200 ppm n-pentanol.
[0022] Figure 5 Graph showing the concentration-response relationship of the CoZr-LDH / rGO composite sensitive material prepared in Examples 1 to 5 of the present invention to 10-50 ppm n-pentanol.
[0023] Figure 6 Graph showing the concentration-response relationship of the CoZr-LDH / rGO composite sensitive material prepared in Examples 1 to 5 of the present invention to 10-200 ppm n-pentanol.
[0024] Figure 7 This is a histogram of the gas-sensitive selectivity of the CoZr-LDH / rGO composite sensitive material prepared in Example 3 of the present invention. DETAILED DESCRIPTION
[0025] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.
[0026] The theories or mechanisms described and disclosed in the present invention, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.
[0027] Throughout this disclosure, all features, such as values, amounts, contents, and concentrations, specified in numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to encompass and specifically disclose all possible subranges and individual values within those ranges (including integers and fractions).
[0028] In the present invention, unless otherwise specified, “comprises,” “includes,” “contains,” “has,” or similar terms encompass the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” encompasses the meanings of “A includes a and other” and “A only includes a.”
[0029] In the present invention, in order to keep the description concise, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification. The present invention will be further described in detail below with reference to specific examples, which are intended to explain the present invention rather than to limit it.
[0030] The present invention discloses a CoZr-LDH / rGO composite sensitive material. The composite sensitive material has Zr and Co as central metal ions and a layered crystal structure with a bimetallic central skeleton. The layered crystal structure contains anionic groups between layers, and the anionic groups include hydroxide ions, nitrate ions, and fluoride ions.
[0031] The present invention discloses a method for preparing a CoZr-LDH / rGO composite sensitive material, referring to Figure 1 , including the following steps: Step 1, using isopropyl alcohol aqueous solution as solvent to prepare 2+ 、Zr 4+ of solution A and solution B.
[0032] Specifically, the preparation method of the isopropyl alcohol aqueous solution is as follows: analytically pure isopropyl alcohol and deionized water are prepared in a volume ratio of 1: (0.5-2.0) to obtain the isopropyl alcohol aqueous solution.
[0033] Analytical pure Co(NO3)2·6H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution A; wherein, Co 2+ The concentration is 1.0 mmol·L -1 .
[0034] Analytical pure Zr(NO3)4·5H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution B; wherein, Zr 4+ The concentration is 5.0 mmol·L-1 .
[0035] Step 2: slowly dropwise adding solution B to solution A, and magnetically stirring to obtain solution C; wherein the molar ratio of Co element to Zr element in solution C is 1:(0.2~5.0).
[0036] Step 3, adding ammonium fluoride to solution C, and stirring magnetically to obtain solution D; wherein, F in solution D - The concentration is 1~10 mmol·L -1 .
[0037] Step 4, adding urea to solution D and stirring magnetically to obtain solution E with a pH value of 2-6; Step 5: adding graphene oxide rGO to solution E and stirring evenly to obtain a precursor solution F; wherein the amount of graphene oxide rGO added is 0.1 wt% to 5 wt% of the total mass of the metal salts in solution E.
[0038] Step 6: The precursor solution F is subjected to an aging reaction, and then cooled, centrifuged, washed and dried to obtain a CoZr-LDH / rGO composite sensitive powder material.
[0039] Specifically, the precursor solution is placed in a polytetrafluoroethylene hydrothermal autoclave and reacted at 90-180°C for 8-20 hours. After the reaction is completed, it is cooled to room temperature with the furnace, the solid-liquid mixture is centrifuged and precipitated, the precipitate is washed with deionized water and ethanol respectively, placed in a drying oven, and dried at 50-90°C for 10-40 hours to obtain powder.
[0040] The present invention discloses a method for preparing a CoZr-LDH / rGO composite sensitive material. Cobalt nitrate hexahydrate and zirconium nitrate pentahydrate are selected as metal sources, which are dissolved in an isopropanol aqueous solution respectively, and the two metal salt solutions are mixed according to a certain molar ratio. Ammonium fluoride is used as an interlayer ion regulator, urea is used to adjust the pH value of the solution, and then graphene oxide is added and stirred evenly to obtain a precursor solution. The obtained mixed precursor suspension is subjected to hydrothermal treatment, and after the high-temperature reaction is completed, it is cooled to room temperature in the furnace, and solid-liquid separation, washing and drying are performed to obtain the target sensitive material. The material has a layered self-assembly structure, a large specific surface area, orderly distribution of metal ions, rich pores, and structural characteristics in which the distribution state of interlayer hydroxyl, amino, and fluoride ions is adjustable. The material has outstanding selective adsorption, strong anti-interference ability, good long-term stability, and high sensitivity to alcohol molecules at room temperature. It is particularly suitable for the needs of high sensitivity, high selectivity, low power consumption, and safe detection of n-pentanol molecules.
[0041] The present invention also discloses a gas sensor comprising the CoZr-LDH / rGO composite sensitive material.
[0042] The present invention also discloses an application of a CoZr-LDH / rGO composite sensitive material in the detection of n-pentanol at room temperature.
[0043] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.
[0044] The following examples utilize conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or as recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art.
[0045] Example 1 Step 1: Prepare an isopropyl alcohol-water mixed solution by mixing analytically pure isopropyl alcohol and deionized water in a volume ratio of 1:0.5.
[0046] Analytical pure Co(NO3)2·6H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution A; wherein, Co 2+ The concentration is 1.0 mmol·L -1 .
[0047] Analytical pure Zr(NO3)4·5H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution B; wherein, Zr 4+ The concentration is 5.0 mmol·L -1 .
[0048] Step 2: slowly dropwise adding solution B into solution A, and continuously stirring under magnetic stirring to obtain solution C, wherein the molar ratio of Co to Zr is 1:0.2.
[0049] Step 3, add ammonium fluoride to solution C to obtain F - The concentration is 2mmol·L -1 of solution D.
[0050] Step 4: adding urea to solution D to obtain solution E with a pH value of 2.
[0051] Step 5: Add graphene oxide to solution E and stir evenly to obtain a precursor solution F, wherein the amount of graphene oxide added is 0.5 wt % of the total mass of the metal salts in solution C.
[0052] Step 6: Place the precursor solution F in a polytetrafluoroethylene hydrothermal reactor and react at 90°C for 8 hours. After the reaction is completed, cool it to room temperature with the furnace, centrifuge the solid-liquid mixture, take the precipitate and wash it three times with deionized water and ethanol respectively, and then place it in a drying oven at 60°C for 12 hours to obtain a powder.
[0053] Example 2 Step 1: Prepare an isopropyl alcohol-water mixed solution by mixing analytically pure isopropyl alcohol and deionized water in a volume ratio of 1:1.
[0054] Analytical pure Co(NO3)2·6H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution A; wherein, Co 2+ The concentration is 1.0 mmol·L -1 .
[0055] Analytical pure Zr(NO3)4·5H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution B; wherein, Zr 4+ The concentration is 5.0 mmol·L -1 .
[0056] Step 2: slowly dropwise adding solution B into solution A, and continuously stirring under magnetic stirring to obtain solution C, wherein the molar ratio of Co to Zr is 1:1.
[0057] Step 3, add ammonium fluoride to solution C to obtain F - The concentration is 2mmol·L -1 of solution D.
[0058] Step 4: adding urea to solution D to adjust the solution to obtain solution E with a pH value of 3.
[0059] Step 5: Add graphene oxide to solution E and stir evenly to obtain a precursor solution F, wherein the amount of graphene oxide added is 1 wt % of the total mass of the metal salts in solution C.
[0060] Step 6: Place the precursor solution F in a polytetrafluoroethylene hydrothermal autoclave and react at 100°C for 9 hours. After the reaction is completed, cool it to room temperature with the furnace, centrifuge the solid-liquid mixture, take the precipitate, wash it three times with deionized water and ethanol respectively, and place it in a drying oven at 60°C for 12 hours to obtain a powder.
[0061] Example 3 Step 1: Prepare an isopropyl alcohol-water mixed solution by mixing analytically pure isopropyl alcohol and deionized water in a volume ratio of 1:1.5.
[0062] Analytical pure Co(NO3)2·6H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution A; wherein, Co 2+ The concentration is 1.0 mmol·L -1 .
[0063] Analytical pure Zr(NO3)4·5H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution B; wherein, Zr 4+ The concentration is 5.0 mmol·L -1 .
[0064] Step 2: slowly dropwise adding solution B into solution A, and continuously stirring under magnetic stirring to obtain solution C, wherein the molar ratio of Co to Zr is 1:2.
[0065] Step 3, add ammonium fluoride to solution C to obtain F - The concentration is 3mmol·L -1 of solution D.
[0066] Step 4: Add urea to solution D to obtain solution E with a pH value of 4.
[0067] Step 5: Add graphene oxide to solution E and stir evenly to obtain a precursor solution F, wherein the amount of graphene oxide added is 3 wt% of the total mass of the metal salts in solution C.
[0068] Step 6: Place the precursor solution F in a polytetrafluoroethylene hydrothermal reactor and react at 120°C for 11 hours. After the reaction is completed, cool it to room temperature with the furnace, centrifuge the solid-liquid mixture, take the precipitate, wash it three times with deionized water and ethanol respectively, and place it in a drying oven at 60°C for 12 hours to obtain a powder.
[0069] Example 4 Step 1: Prepare an isopropyl alcohol-water mixed solution by mixing analytically pure isopropyl alcohol and deionized water in a volume ratio of 1:1.5.
[0070] Analytical pure Co(NO3)2·6H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution A; wherein, Co 2+ The concentration is 1.0 mmol·L -1 .
[0071] Analytical pure Zr(NO3)4·5H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution B; wherein, Zr 4+ The concentration is 5.0 mmol·L -1 .
[0072] Step 2: slowly dropwise adding solution B into solution A, and continuously stirring under magnetic stirring to obtain solution C, wherein the molar ratio of Co to Zr is 1:3.0.
[0073] Step 3, add ammonium fluoride to solution C to obtain F - The concentration is 4 mmol·L -1 of solution D.
[0074] Step 4: adding urea to solution D to obtain solution E with a pH value of 5.
[0075] Step 5: Add graphene oxide to solution E and stir evenly to obtain a precursor solution F, wherein the amount of graphene oxide added is 4 wt% of the total mass of the metal salts in solution C.
[0076] Step 6: Place the precursor solution F in a polytetrafluoroethylene hydrothermal autoclave and react at 130°C for 13 hours. After the reaction is completed, cool it to room temperature with the furnace, centrifuge the solid-liquid mixture, take the precipitate, wash it three times with deionized water and ethanol respectively, and place it in a drying oven at 60°C for 12 hours to obtain a powder.
[0077] Example 5 Step 1: Prepare an isopropyl alcohol-water mixed solution by mixing analytically pure isopropyl alcohol and deionized water in a volume ratio of 1:2.0.
[0078] Analytical pure Co(NO3)2·6H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution A; wherein, Co 2+ The concentration is 1.0 mmol·L -1 .
[0079] Analytical pure Zr(NO3)4·5H2O was dissolved in isopropanol aqueous solution and stirred magnetically until completely dissolved to obtain solution B; wherein, Zr 4+ The concentration is 5.0 mmol·L -1 .
[0080] Step 2: slowly dropwise adding solution B into solution A, and continuously stirring under magnetic stirring to obtain solution C, wherein the molar ratio of Co to Zr is 1:4.0.
[0081] Step 3, add ammonium fluoride to solution C to obtain F - The concentration is 5mmol·L -1 of solution D.
[0082] Step 4: adding urea to solution D to obtain solution E with a pH value of 5.
[0083] Step 5: Add graphene oxide to solution E and stir evenly to obtain a precursor solution F, wherein the amount of graphene oxide added is 5 wt% of the total mass of the metal salts in solution C.
[0084] Step 6: Place the precursor solution F in a polytetrafluoroethylene hydrothermal reactor and react at 140°C for 14 h. After the reaction is completed, cool it to room temperature with the furnace, centrifuge the solid-liquid mixture, take the precipitate and wash it three times with deionized water and ethanol respectively, and then place it in a drying oven at 60°C for 12 h to obtain a powder.
[0085] The performance of the CoZr-LDH / rGO composite sensitive materials prepared in Examples 1 to 5 was tested.
[0086] 1. X-ray diffraction experiment The XRD patterns of the CoZr-LDH / rGO composite sensitive materials prepared in Examples 1 to 5 were obtained by X-ray diffractometer (XRD). Figure 2 As shown in Figure 2 , all curves exhibit distinct diffraction peaks at approximately 20°, 26°, and 36° 2θ. This indicates that each sample has the same crystal structure. The intensity of the diffraction peak is related to the crystallinity of the sample. A higher intensity indicates a higher degree of crystallinity. Therefore, CT4 has the highest crystallinity, while CT0.5 has the lowest.
[0087] 2. Scanning electron microscopy experiment The scanning electron microscope images of the CoZr-LDH / rGO composite sensitive materials prepared in Examples 1 to 5 were obtained by scanning the CoZr-LDH / rGO composite sensitive materials in Examples 1 to 5. Figure 3 As shown in Figure 1, the microstructure of image a is denser, possibly indicating higher crystallinity or smaller grain size. The microstructure of image b is more dispersed, possibly indicating lower crystallinity or larger grain size. The microstructures of images c, d, and e are intermediate between those of images a and b.
[0088] 3. Response experiment of CoZr-LDH / rGO composite sensitive material to n-pentanol under different temperature conditions The CoZr-LDH / rGO composite sensitive materials prepared in Examples 1 to 5 were used to detect the response of the materials to 200 ppm n-pentanol at different temperatures.
[0089] The experimental results are as follows Figure 4 As shown, it can be seen that the optimal working temperature of the CoZr-LDH / rGO composite sensitive material is 40°C, which can achieve the goal of room temperature sensitivity.
[0090] 4. Response experiment of CoZr-LDH / rGO composite sensitive materials with different concentrations to n-pentanol The CoZr-LDH / rGO composite sensitive material prepared in Examples 1 to 5 was used to detect n-pentanol atmospheres in two concentration ranges of 10 to 50 ppm and 50 to 200 ppm to obtain the response values of the material.
[0091] The experimental results are as follows Figure 5 、 6 As shown, it can be seen that the concentration-response of the materials conforms to the linear growth law, among which the material prepared in Example 3 has the best sensitivity.
[0092] 5. Response experiment of CoZr-LDH / rGO composite sensitive material to different target gases The experimental results are as follows Figure 7 As shown, the CoZr-LDH / rGO composite sensitive material is selectively sensitive to n-pentanol.
[0093] The above description is merely a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and replacements, and these modifications and replacements are also within the scope of protection covered by the claims.
Claims
1. A CoZr-LDH / rGO composite sensitive material, characterized in that: The composite sensitive material has Zr and Co as central metal ions and a layered crystal structure with a bimetallic central skeleton. The layered crystal structure contains anionic groups between layers, and the anionic groups include hydroxide ions, nitrate ions, and fluoride ions.
2. A method for preparing the CoZr-LDH / rGO composite sensitive material according to claim 1, characterized in that: The following steps are involved: Step 1, using isopropyl alcohol aqueous solution as solvent to prepare 2+ 、Zr 4+ Solution A and solution B; Step 2, adding solution B to solution A and stirring to obtain solution C; Step 3, adding ammonium fluoride to solution C and stirring to obtain solution D; Step 4, adding urea to solution D and stirring to obtain solution E; Step 5, adding graphene oxide rGO to solution E and stirring evenly to obtain a precursor solution F; Step 6: The precursor solution F is subjected to an aging reaction, and then cooled, centrifuged, washed and dried to obtain a CoZr-LDH / rGO composite sensitive powder material.
3. The method for preparing the CoZr-LDH / rGO composite sensitive material according to claim 2, characterized in that: In step 1, the isopropyl alcohol aqueous solution is prepared by mixing analytically pure isopropyl alcohol and deionized water in a volume ratio of 1:(0.5-2.0) to obtain an isopropyl alcohol aqueous solution; Co in solution A 2+ The concentration is 1.0 mmol·L -1 , Zr in solution B 4+ The concentration is 5.0 mmol·L -1 .
4. The method for preparing the CoZr-LDH / rGO composite sensitive material according to claim 2, characterized in that: In step 2, the molar ratio of the Co element to the Zr element in solution C is 1:(0.2~5.0).
5. The method for preparing the CoZr-LDH / rGO composite sensitive material according to claim 2, characterized in that: In step 3, F in solution D - The concentration is 1~10 mmol·L -1 .
6. The method for preparing the CoZr-LDH / rGO composite sensitive material according to claim 2, wherein: In step 4, the pH value of solution E is 2-6.
7. The method for preparing the CoZr-LDH / rGO composite sensitive material according to claim 2, characterized in that: In step 5, the amount of graphene oxide rGO added is 0.1 wt% to 5 wt% of the total mass of the metal salts in solution E.
8. The method for preparing the CoZr-LDH / rGO composite sensitive material according to claim 2, characterized in that: Step 6: During the aging reaction, the temperature is 90-180°C and the time is 8-20 hours; When cooling, use furnace cooling to room temperature; After centrifugation, the precipitate was washed with deionized water and ethanol respectively; When drying, the temperature is 50~80℃ and the time is 10~40 hours.
9. A gas sensor comprising the CoZr-LDH / rGO composite sensitive material according to claim 1.
10. Use of the CoZr-LDH / rGO composite sensitive material according to claim 1 in the detection of n-pentanol at room temperature.