Iodine-doped bismuth oxychloride nanosheets, and preparation method and application thereof
Iodine-doped bismuth oxychloride nanosheets were synthesized via a hydrothermal method using polyethylene glycol catalyst, solving the problem of poor resistive switching performance of bismuth oxychloride. This enabled the fabrication and simulation of resistive switching performance of memristor devices, which are suitable for neuromorphic computing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SICHUAN NORMAL UNIV
- Filing Date
- 2023-10-16
- Publication Date
- 2026-06-30
AI Technical Summary
Existing bismuth oxychloride and bismuth iodide have poor resistive switching performance, and their nanosheet size is not suitable for memristors, especially in neuromorphic computing and simulation of resistive switching performance.
Iodine-doped bismuth oxychloride nanosheets were synthesized via a hydrothermal method using polyethylene glycol as a catalyst. The iodine-doped bismuth oxychloride nanosheets were then prepared by mechanical exfoliation and transferred onto a SiO2/Si substrate to fabricate Pt/I-BiOCl/Pt memristor devices.
The prepared iodine-doped bismuth oxychloride nanosheets have increased size and a wider range of applications. They exhibit resistive switching properties and can be applied to memristor devices to simulate biological synaptic behavior, making them suitable for neuromorphic computing.
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Figure CN117401713B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nanomaterials and components, specifically relating to an iodine-doped bismuth oxychloride nanosheet, its preparation method, and its application. Background Technology
[0002] A memristor is short for memory resistor, and it is the fourth type of electronic component after resistors, capacitors, and inductors. Unlike ordinary resistors, memristors are non-linear resistors with memory function. Their resistance is affected by the current, and they have the ability to remember charge, thus enabling them to remember and store data.
[0003] The resistive switching characteristic, or resistive switching behavior for short, refers to the phenomenon where the resistance of a memristor changes under the stimulation of an applied electric field, typically exhibiting multiple resistance states. Analysis of the current-voltage (IV) characteristic curve reveals that resistive switching behavior can be broadly categorized into four types: digital bipolar resistive switching, unipolar resistive switching, threshold switching, and analog resistive switching. Analog resistive switching refers to a slow change in resistance, exhibiting a series of adjustable resistance states. Memristor analog resistive switching behavior is characterized by continuous and coordinated changes in conductance, meeting the functional requirements of biological synapses. Memristors with analog resistive switching behavior can be applied in neuromorphic computing.
[0004] Research has found that bismuth oxychloride nanosheets synthesized via a hydrothermal method, when mechanically exfoliated to create memristors, lack any resistive switching properties, making them unsuitable for neuromorphic computing. In contrast, two-dimensional bismuth oxyiodide exhibits excellent resistive switching properties, displaying digital resistive switching behavior suitable for data storage, but not the analog resistive switching required for neuromorphic computing. Iodine doping of bismuth oxychloride can effectively enhance its photocatalytic performance, but currently available methods synthesize iodine-doped bismuth oxychloride only at the nanometer scale, failing to achieve the micrometer-sized dimensions required for memristor device fabrication. Summary of the Invention
[0005] The problem to be solved by this invention is to provide an iodine-doped bismuth oxychloride nanosheet, its preparation method and application, so as to solve the problems of poor resistive switching performance of bismuth oxychloride and bismuth oxyiodide and the unsuitability of nanosheet size for memristors.
[0006] The technical solution adopted to solve the technical problem is to provide a method for preparing iodine-doped bismuth oxychloride nanosheets, including the following steps:
[0007] (1) C7H 13 IN2 is dissolved in anhydrous acetic acid, and then Bi(NO3)3·5H2O is added and stirred evenly to obtain suspension A;
[0008] (2) Dissolve KCl in distilled water to obtain solution B;
[0009] (3) Add solution B dropwise to suspension A, then add polyethylene glycol, and stir for 40-80 minutes to obtain suspension C;
[0010] (4) The suspension C was transferred to a polytetrafluoroethylene liner and reacted at 160-200℃ for 22-26h. After cooling to room temperature, it was taken out, filtered, and washed three times with distilled water and anhydrous ethanol respectively. Then it was dispersed in anhydrous ethanol and dried at 55-65℃ for 10-14h to obtain iodine-doped bismuth oxychloride bulk material.
[0011] (5) The iodine-doped bismuth oxychloride bulk is mechanically peeled off, and the peeled iodine-doped bismuth oxychloride is transferred to a SiO2 / Si substrate to obtain iodine-doped bismuth oxychloride nanosheets.
[0012] The beneficial effects of the above-mentioned technical solution of the present invention are as follows: Polyethylene glycol is a compound with a linear polymer structure, which is formed by ethylene glycol molecules linked by ester bonds. Its molecular structure contains a large number of oxygen atoms. These oxygen atoms can form hydrogen bonds with hydrogen atoms in the reactants, thereby enhancing the interaction between the reactants. Using polyethylene glycol as a catalyst can make the reaction more complete, which is beneficial to increasing the size of iodine-doped bismuth oxychloride nanosheets. The iodine-doped bismuth oxychloride nanosheets prepared by the above preparation method have large size and wide applicability.
[0013] Preferably, in step (1) C7H 13 The feed-to-liquid ratio of IN2 to anhydrous acetic acid is 0.2–0.3 g: 20 mL, C7H 13 The mass ratio of IN2 to Bi(NO3)3·5H2O is 5~6:19~20.
[0014] Preferably, in step (2), the ratio of KCl to distilled water is 1.4-1.5 g: 100 mL.
[0015] Preferably, the volume ratio of suspension A to solution B is 4:1, and the mass ratio of polyethylene glycol to KCl is 1:14-15; in step (3), the dropping rate is 30 drops / min, and the stirring time is 60min.
[0016] Preferably, in step (4), the reaction temperature is 180°C and the reaction time is 24h; the drying temperature is 60°C and the drying time is 12h.
[0017] The present invention also provides iodine-doped bismuth oxychloride nanosheets prepared by the above preparation method.
[0018] This invention also provides the application of the above-mentioned iodine-doped bismuth oxychloride nanosheets in the preparation of Pt / I-BiOCl / Pt memristor devices.
[0019] Preferably, the application of iodine-doped bismuth oxychloride nanosheets in the fabrication of Pt / I-BiOCl / Pt memristor devices includes the following steps:
[0020] Iodine-doped bismuth oxychloride nanosheets were placed on a spin coater, and 1-2 drops of photoresist were dropped onto the SiO2 / Si substrate surface of the iodine-doped bismuth oxychloride nanosheets. The spin coater was run at 2500-3500 r / min for 25-35 s, and then dried. Photolithography was performed on both ends of the iodine-doped bismuth oxychloride nanosheets, and the exposure time was 15-25 s. The treated iodine-doped bismuth oxychloride nanosheets were immersed in the developer for 1 min, and then removed and dried. The dried iodine-doped bismuth oxychloride nanosheets were placed on the stage of a sputtering instrument and the stage height was adjusted. The nanosheets were sputtered three times with a high-purity Pt target for 20 s each time. The nanosheets were then soaked in acetone for 7-9 min, washed with distilled water, sonicated, and dried to obtain the Pt / I-BiOCl / Pt memristor device.
[0021] The beneficial effects of the preferred technical solution of the present invention are as follows: uniform photoresist is formed on the surface of SiO2 / Si substrate by homogenization; high-purity Pt target material can be deposited on the surface of SiO2 / Si substrate by sputtering instrument, and excess photoresist and metal Pt are removed by acetone immersion.
[0022] More preferably, the rotation speed is 3000 r / min and the homogenization time is 30 s.
[0023] More preferably, the exposure time is 20 seconds and the acetone soaking time is 8 minutes.
[0024] The present invention has the following beneficial effects:
[0025] (1) The present invention uses polyethylene glycol as a catalyst to prepare iodine-doped bismuth oxychloride nanosheets, which can make the reaction more thorough, increase the size of hydrothermal synthesized iodine-doped bismuth oxychloride, and is more conducive to the preparation of memristor devices.
[0026] (2) The iodine-doped bismuth oxychloride nanosheets prepared by the present invention are applied to the fabrication of memristor devices and exhibit simulated resistive switching performance, thereby increasing the application range of bismuth oxychloride nanosheets.
[0027] (3) The Pt / I-BiOCl / Pt memristor device prepared in this invention has simulated resistive switching performance, can simulate biological synaptic behavior, and can be applied to fields such as simulating artificial neural synapses and neuromorphic computing. Attached Figure Description
[0028] Figure 1 This is an optical microscope image of iodine-doped bismuth oxychloride prepared by adding polyethylene glycol on a SiO2 substrate;
[0029] Figure 2This is a schematic diagram of the structure of a Pt / I-BiOCl / Pt memristor device prepared from iodine-doped bismuth oxychloride nanosheets.
[0030] Figure 3 This is an optical microscope image of iodine-doped bismuth oxychloride prepared without the addition of polyethylene glycol on a SiO2 substrate;
[0031] Figure 4 This is an IV test image of a Pt / BiOCl / Pt memristor device fabricated from bismuth oxychloride nanosheets without iodine doping.
[0032] Figure 5 This is a simulated resistive switching performance diagram of a Pt / I-BiOCl / Pt memristor device prepared from iodine-doped bismuth oxychloride nanosheets;
[0033] Figure 6 This is a functional diagram of long-term enhancement (LTP) and long-term suppression (LTD) of Pt / I-BiOCl / Pt memristor devices prepared from iodine-doped bismuth oxychloride nanosheets. Detailed Implementation
[0034] The features and performance of the present invention will be further described in detail below with reference to embodiments.
[0035] Example 1
[0036] An iodine-doped bismuth oxychloride nanosheet is prepared by the following steps:
[0037] (1) Weigh 0.502g of C7H 13 IN2 was dissolved in 40 mL of anhydrous acetic acid, and then 1.9403 g of Bi(NO3)3·5H2O was added. The mixture was stirred magnetically until homogeneous to obtain suspension A.
[0038] (2) Weigh 0.1491 g of KCl and dissolve it in 10 mL of distilled water to obtain solution B;
[0039] (3) Add solution B to suspension A at a dropping rate of 30 drops / min, then add 10 mg of polyethylene glycol, and stir magnetically for 60 min to obtain suspension C;
[0040] (4) The suspension C was transferred to a 100 mL polytetrafluoroethylene liner and placed in a reaction vessel. It was reacted at 180 °C for 24 h. After cooling to room temperature, it was taken out, filtered, and washed three times with distilled water and anhydrous ethanol respectively. Then it was dispersed in anhydrous ethanol and dried at 60 °C for 12 h to obtain iodine-doped bismuth oxychloride bulk.
[0041] (5) The iodine-doped bismuth oxychloride bulk is mechanically peeled off multiple times on the tape, and then it is adhered to the tape to obtain the iodine-doped bismuth oxychloride transferred to the SiO2 / Si substrate, thus obtaining iodine-doped bismuth oxychloride nanosheets.
[0042] The application of the iodine-doped bismuth oxychloride nanosheets prepared in this embodiment in the fabrication of Pt / I-BiOCl / Pt memristor devices includes the following steps:
[0043] Iodine-doped bismuth oxychloride nanosheets were placed on a spin coater, and 1-2 drops of photoresist were dropped onto the SiO2 / Si substrate surface of the iodine-doped bismuth oxychloride nanosheets. The spin coater was run at 3000 r / min for 30 s, and then dried. Photolithography was performed on both ends of the iodine-doped bismuth oxychloride nanosheets, and the exposure time was 20 s. The treated iodine-doped bismuth oxychloride nanosheets were immersed in the developer for 1 min, and then dried. The dried iodine-doped bismuth oxychloride nanosheets were placed on the stage of a sputtering instrument and the stage height was adjusted. The nanosheets were sputtered three times with a high-purity Pt target for 20 s each time. The nanosheets were then soaked in acetone for 8 min, washed with distilled water, sonicated, and dried to obtain the Pt / I-BiOCl / Pt memristor device.
[0044] Example 2
[0045] An iodine-doped bismuth oxychloride nanosheet is prepared by the following steps:
[0046] (1) Weigh 0.502g of C7H 13 IN2 was dissolved in 40 mL of anhydrous acetic acid, and then 1.9403 g of Bi(NO3)3·5H2O was added. The mixture was stirred magnetically until homogeneous to obtain suspension A.
[0047] (2) Weigh 0.1491 g of KCl and dissolve it in 10 mL of distilled water to obtain solution B;
[0048] (3) Add solution B to suspension A at a dropping rate of 30 drops / min, then add 10 mg of polyethylene glycol, and stir magnetically for 40 min to obtain suspension C;
[0049] (4) The suspension C was transferred to a 100 mL polytetrafluoroethylene liner and placed in a reaction vessel. It was reacted at 160 °C for 26 h. After cooling to room temperature, it was taken out, filtered, and washed three times with distilled water and anhydrous ethanol respectively. Then it was dispersed in anhydrous ethanol and dried at 55 °C for 14 h to obtain iodine-doped bismuth oxychloride bulk.
[0050] (5) The iodine-doped bismuth oxychloride bulk is mechanically peeled off multiple times on the tape, and then it is adhered to the tape to obtain the iodine-doped bismuth oxychloride transferred to the SiO2 / Si substrate, thus obtaining iodine-doped bismuth oxychloride nanosheets.
[0051] The application of the iodine-doped bismuth oxychloride nanosheets prepared in this embodiment in the fabrication of Pt / I-BiOCl / Pt memristor devices includes the following steps:
[0052] Iodine-doped bismuth oxychloride nanosheets were placed on a spin coater, and 1-2 drops of photoresist were dropped onto the SiO2 / Si substrate surface of the iodine-doped bismuth oxychloride nanosheets. The spin coater was run at 2500 r / min for 35 s, and then dried. Photolithography was performed on both ends of the iodine-doped bismuth oxychloride nanosheets, and the exposure time was 15 s. The treated iodine-doped bismuth oxychloride nanosheets were immersed in the developer for 1 min, and then removed and dried. The dried iodine-doped bismuth oxychloride nanosheets were placed on the stage of a sputtering instrument and the stage height was adjusted. The nanosheets were sputtered three times with a high-purity Pt target for 20 s each time. The nanosheets were then soaked in acetone for 7 min, washed with distilled water, sonicated, and dried to obtain the Pt / I-BiOCl / Pt memristor device.
[0053] Example 3
[0054] An iodine-doped bismuth oxychloride nanosheet is prepared by the following steps:
[0055] (1) Weigh 0.502g of C7H 13 IN2 was dissolved in 40 mL of anhydrous acetic acid, and then 1.9403 g of Bi(NO3)3·5H2O was added. The mixture was stirred magnetically until homogeneous to obtain suspension A.
[0056] (2) Weigh 0.1491 g of KCl and dissolve it in 10 mL of distilled water to obtain solution B;
[0057] (3) Add solution B to suspension A at a dropping rate of 30 drops / min, then add 10 mg of polyethylene glycol, and stir magnetically for 80 min to obtain suspension C;
[0058] (4) The suspension C was transferred to a 100 mL polytetrafluoroethylene liner and placed in a reaction vessel. It was reacted at 200 °C for 22 h. After cooling to room temperature, it was taken out, filtered, and washed three times with distilled water and anhydrous ethanol respectively. Then it was dispersed in anhydrous ethanol and dried at 65 °C for 10 h to obtain iodine-doped bismuth oxychloride bulk.
[0059] (5) The iodine-doped bismuth oxychloride bulk is mechanically peeled off multiple times on the tape, and then it is adhered to the tape to obtain the iodine-doped bismuth oxychloride transferred to the SiO2 / Si substrate, thus obtaining iodine-doped bismuth oxychloride nanosheets.
[0060] The application of the iodine-doped bismuth oxychloride nanosheets prepared in this embodiment in the fabrication of Pt / I-BiOCl / Pt memristor devices includes the following steps:
[0061] Iodine-doped bismuth oxychloride nanosheets were placed on a spin coater, and 1-2 drops of photoresist were dropped onto the SiO2 / Si substrate surface of the iodine-doped bismuth oxychloride nanosheets. The spin coater was run at 3500 r / min for 25 s, and then dried. Photolithography was performed on both ends of the iodine-doped bismuth oxychloride nanosheets, and the exposure time was 25 s. The treated iodine-doped bismuth oxychloride nanosheets were immersed in the developer for 1 min, and then removed and dried. The dried iodine-doped bismuth oxychloride nanosheets were placed on the stage of a sputtering instrument and the stage height was adjusted. The nanosheets were sputtered three times with a high-purity Pt target for 20 s each time. The nanosheets were then soaked in acetone for 9 min, washed with distilled water, sonicated, and dried to obtain the Pt / I-BiOCl / Pt memristor device.
[0062] Comparative Example 1
[0063] In the preparation of an iodine-doped bismuth oxychloride nanosheet, compared with Example 1, polyethylene glycol was not added in step (3); the remaining steps were the same as in Example 1.
[0064] The application of the iodine-doped bismuth oxychloride nanosheets prepared in this comparative example in the fabrication of Pt / I-BiOCl / Pt memristor devices follows the same steps as in Example 1.
[0065] Comparative Example 2
[0066] In the preparation of an iodine-doped bismuth oxychloride nanosheet, compared with Example 1, step (1) is as follows: Bi(NO3)3·5H2O is dissolved in anhydrous acetic acid and stirred evenly to obtain suspension A; the remaining steps are the same as in Example 1.
[0067] The application of the iodine-doped bismuth oxychloride nanosheets prepared in this comparative example in the fabrication of Pt / BiOCl / Pt memristor devices follows the same steps as in Example 1.
[0068] Experimental Example
[0069] The performance of the memristor devices in Example 1, Comparative Example 1, and Comparative Example 2 was measured, and the results are as follows: Figures 1-6 As shown.
[0070] from Figures 1-3 It is known that the size of iodine-doped bismuth oxychloride prepared with polyethylene glycol as a catalyst is tens to hundreds of micrometers in SiO2 substrate, which is more conducive to the preparation of Pt / I-BiOCl / Pt memristor devices; while the size of iodine-doped bismuth oxychloride prepared without polyethylene glycol as a catalyst is about 1 μm in SiO2 substrate, which cannot reach the size of more than 10 μm required for the preparation of memristor devices.
[0071] from Figures 4-6 It can be seen that the iodine-doped Pt / I-BiOCl / Pt memristor device exhibits simulated resistive switching performance, and the current increases from 6.0 × 10⁻⁶ to 6.0 × 10⁻⁶ as the number of scans increases.-10 A decreased to 2.3 × 10 -10 A. The Pt / BiOCl / Pt memristor device prepared without iodine doping did not exhibit any resistive switching performance, indicating that iodine doping can effectively change the performance of memristor devices. This simulated resistive switching behavior allows the memristor device to effectively simulate biological synaptic behavior, such as long-term enhancement (LTP) and long-term inhibition (LTD). Furthermore, LTP and LTD exhibit excellent linearity, enabling the bismuth oxychloride material, which originally did not have resistive switching performance, to simulate resistive switching. This further enables the realization of neural synaptic functions such as LTP and LTD, which is beneficial for subsequent applications in neuromorphic computing.
[0072] The present invention has been described according to the above embodiments. It should be understood that the above embodiments do not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent transformation fall within the scope of the present invention.
Claims
1. The application of iodine-doped bismuth oxychloride nanosheets in the fabrication of Pt / I-BiOCl / Pt memristor devices, characterized in that, Includes the following steps: Iodine-doped bismuth oxychloride nanosheets were placed on a spin coater, and 1-2 drops of photoresist were dropped onto the SiO2 / Si substrate surface of the iodine-doped bismuth oxychloride nanosheets. The spin coater was run at 2500-3500 r / min for 25-35 s, and then dried. Photolithography was performed on both ends of the iodine-doped bismuth oxychloride nanosheets, and the exposure time was 15-25 s. The treated iodine-doped bismuth oxychloride nanosheets were immersed in the developer for 1 min, and then removed and dried. The dried iodine-doped bismuth oxychloride nanosheets were placed on the stage of a sputtering instrument and the stage height was adjusted. The nanosheets were sputtered three times with a high-purity Pt target for 20 s each time. The nanosheets were then soaked in acetone for 7-9 min, washed with distilled water, sonicated, and dried to obtain the Pt / I-BiOCl / Pt memristor device. The method for preparing the iodine-doped bismuth oxychloride nanosheets includes the following steps: (1) C7H 13 IN2 is dissolved in anhydrous acetic acid, and then Bi(NO3)3·5H2O is added and stirred evenly to obtain suspension A; (2) Dissolve KCl in distilled water to obtain solution B; (3) Add solution B dropwise to suspension A, then add polyethylene glycol, stir for 40-80 min to obtain suspension C; (4) Transfer the suspension C to a polytetrafluoroethylene liner and react at 160~200℃ for 22~26h. After cooling to room temperature, remove it, filter it, wash it three times with distilled water and anhydrous ethanol respectively, then disperse it in anhydrous ethanol and dry it at 55~65℃ for 10~14h to obtain iodine-doped bismuth oxychloride bulk material. (5) Mechanically peel off the iodine-doped bismuth oxychloride bulk and transfer the peeled iodine-doped bismuth oxychloride onto a SiO2 / Si substrate to obtain iodine-doped bismuth oxychloride nanosheets.
2. The application as described in claim 1, characterized in that: In step (1), C7H 13 The feed-to-solid ratio of IN2 to anhydrous acetic acid is 0.2~0.3g:20mL, C7H 13 The mass ratio of IN2 to Bi(NO3)3·5H2O is 5~6:19~20.
3. The application as described in claim 2, characterized in that: In step (2), the ratio of KCl to distilled water is 1.4~1.5g:100mL.
4. The application as described in claim 3, characterized in that: The volume ratio of suspension A to solution B is 4:1, and the mass ratio of polyethylene glycol to KCl is 1:14~15; in step (3), the dropping rate is 30 drops / min, and the stirring time is 60min.
5. The application as described in claim 1, characterized in that: In step (4), the reaction temperature is 180℃ and the reaction time is 24h; the drying temperature is 60℃ and the drying time is 12h.