Preparation method of upright graphene nanorod, upright graphene nanorod, application and concentration detection method
By lowering the secondary growth temperature of vertical graphene and using methane and ammonia to grow vertical graphene nanorods at a specific temperature, the problems of high preparation cost and limited detection performance were solved, achieving low-cost and efficient SERS detection.
Patent Information
- Application Number
- CN202511578594.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-03-17
AI Technical Summary
The existing preparation cost of vertical graphene is high and its SERS detection performance is limited, making it impossible to achieve both low cost and high performance.
By lowering the secondary growth temperature of upright graphene, upright graphene nanorods were grown at 620℃-660℃ using methane and ammonia to form a rod-shaped structure, and the growth process was controlled by a radio frequency plasma source.
We achieved low-cost preparation of upright graphene nanorods while maintaining or improving the concentration detection capabilities of rhodamine 6G, erythrosine B, and crystal violet, thus reducing preparation costs and enhancing SERS performance.
Smart Images
Figure CN121672506A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of SERS detection, and in particular to a method for preparing upright graphene nanorods, the upright graphene nanorods, their applications, and a method for concentration detection. Background Technology
[0002] Surface-enhanced Raman scattering (SERS) is an important spectroscopic analysis technique that enhances the Raman scattering signal of molecules adsorbed on the surface of specific nanostructures, thereby improving the detection sensitivity and characterization capabilities of molecules. After decades of development, SERS technology has expanded from basic research to many cutting-edge fields such as chemical sensing, materials characterization, biomedical detection (e.g., disease biomarker identification), environmental pollutant monitoring, and food safety analysis, becoming a powerful tool for trace analysis.
[0003] Among them, upright graphene is widely used in the field of SERS detection due to its low preparation cost. The SERS detection performance of upright graphene is affected by its morphology. The inventors disclosed a flower-like upright graphene in prior application 2023115486401, which exhibited excellent SERS detection performance. This upright graphene requires two growth processes to form the flower-like morphology. The second growth process requires a temperature of no less than 700℃, resulting in high energy consumption and limiting further reductions in the preparation cost of upright graphene. However, lowering the temperature of the second growth process prevents the formation of the flower-like morphology, thus reducing the SERS detection performance of the upright graphene. Summary of the Invention
[0004] Therefore, it is necessary to address the issue that vertical graphene is difficult to balance low cost and SERS detection performance by providing a method for preparing vertical graphene nanorods, their applications, and a method for concentration detection.
[0005] A method for preparing upright graphene nanorods, comprising:
[0006] The substrate is placed in the growth chamber and then heated to T1, wherein 500℃≤T1≤600℃;
[0007] The radio frequency plasma source is turned on, and methane is introduced into the growth chamber to grow upright graphene on the substrate for the first time.
[0008] The radio frequency plasma source was turned off, and the introduction of methane into the growth chamber was stopped;
[0009] The substrate is heated to T2, wherein 620℃≤T2≤660℃;
[0010] The radio frequency plasma source is turned on again, and methane and ammonia are introduced into the growth chamber to grow upright graphene on the substrate for the second time, thereby obtaining upright graphene nanorods.
[0011] In one embodiment, during the first growth of upright graphene, the methane flow rate is 8 sccm-12 sccm, the power of the radio frequency plasma source is 180W-220W, and the growth time is 50min-70min.
[0012] In one embodiment, during the second growth of upright graphene, the flow rate of methane is 8 sccm-12 sccm, the flow rate of ammonia is 0.5 sccm-2 sccm, the power of the radio frequency plasma source is 230W-270W, and the growth time is 10min-20min.
[0013] An upright graphene nanorod is prepared using the method described above.
[0014] An application of the described upright graphene nanorods in the detection of Rhodamine 6G.
[0015] A method for detecting rhodamine 6G concentration, comprising:
[0016] Obtain the 1345 cm⁻¹ Raman spectrum of the upright graphene nanorods. -1 Intensity a at point 1345 ;
[0017] The test solution was dropped onto the upright graphene nanorods, and the Raman spectrum of the upright graphene nanorods at 1345 cm⁻¹ was obtained again. -1 Intensity A at point 1345 ;
[0018] At least based on a 1345 and A 1345 Determine the concentration of Rhodamine 6G in the test solution.
[0019] A method for detecting rhodamine 6G concentration, comprising:
[0020] Obtain the 1590 cm⁻¹ Raman spectrum of the upright graphene nanorods. -1 Intensity a at point 1590 ;
[0021] The test solution was dropped onto the upright graphene nanorods, and the Raman spectrum of the upright graphene nanorods at 1590 cm⁻¹ was obtained again. -1 Intensity A at point 1590 ;
[0022] At least based on a 1590 and A 1590Determine the concentration of Rhodamine 6G in the test solution.
[0023] An application of the described upright graphene nanorods in the detection of erythrosine B.
[0024] A method for detecting erythrosine B concentration includes:
[0025] Obtain the 1360 cm⁻¹ Raman spectrum of the upright graphene nanorods. -1 Intensity a at point 1360 ;
[0026] The test solution was dropped onto the upright graphene nanorods, and the Raman spectrum of the upright graphene nanorods at 1360 cm⁻¹ was obtained again. -1 Intensity A at point 1360 ;
[0027] At least based on a 1360 and A 1360 Determine the concentration of erythromycin B in the test solution.
[0028] A method for detecting erythrosine B concentration includes:
[0029] Obtain the 1610 cm⁻¹ Raman spectrum of the upright graphene nanorods. -1 Intensity a at point 1610 ;
[0030] The test solution was dropped onto the upright graphene nanorods, and the Raman spectrum of the upright graphene nanorods at 1610 cm⁻¹ was obtained again. -1 Intensity A at point 1610 ;
[0031] At least based on a 1610 and A 1610 Determine the concentration of erythromycin B in the test solution.
[0032] An application of the aforementioned upright graphene nanorods in the detection of crystal violet.
[0033] A method for detecting crystal violet concentration, comprising:
[0034] Obtain the 1355 cm⁻¹ Raman spectrum of the upright graphene nanorods. -1 Intensity a at point 1355 ;
[0035] The test solution was dropped onto the upright graphene nanorods, and the Raman spectrum of the upright graphene nanorods at 1355 cm⁻¹ was obtained again. -1 Intensity A at point 1355 ;
[0036] At least based on a 1355 and A1355 Determine the concentration of crystal violet in the solution to be tested.
[0037] A method for detecting crystal violet concentration, comprising:
[0038] Obtain the 1590 cm⁻¹ Raman spectrum of the upright graphene nanorods. -1 Intensity a at point 1590 ;
[0039] The test solution was dropped onto the upright graphene nanorods, and the Raman spectrum of the upright graphene nanorods at 1590 cm⁻¹ was obtained again. -1 Intensity A at point 1590 ;
[0040] At least based on a 1590 and A 1590 Determine the concentration of crystal violet in the solution to be tested.
[0041] The beneficial effects of this invention are as follows:
[0042] This invention reduces the preparation cost of upright graphene by lowering the temperature during the second growth process, and simultaneously transforms the final morphology of the upright graphene from a flower-like cluster to a rod-like structure. While this morphological change reduces porosity and hydrophobicity, the upright graphene nanorods maintain a similar ability to detect the concentrations of Rhodamine 6G and erythrosine B as those of flower-like upright graphene, and even outperform those for detecting the concentration of crystal violet. Therefore, the upright graphene nanorods of this invention simultaneously achieve low preparation cost and excellent SERS performance, enabling the detection of the concentrations of Rhodamine 6G, erythrosine B, and crystal violet at a lower cost. Attached Figure Description
[0043] Figure 1 This is a SEM image of the upright graphene in Comparative Example 1 of the present invention.
[0044] Figure 2 This is a SEM image of the upright graphene nanorods in Example 1 of the present invention;
[0045] Figure 3 A photograph of plant glands;
[0046] Figure 4 The image shows the AFM image of the upright graphene nanorods in Example 1 of this invention.
[0047] Figure 5 This is a height distribution diagram of the upright graphene nanorods on the substrate in Example 1 of the present invention;
[0048] Figure 6Porosity test diagram of upright graphene nanorods in Example 1 of this invention;
[0049] Figure 7 This is a normalized local electric field distribution diagram of the upright graphene nanorods in Example 1 of the present invention;
[0050] Figure 8 This is a water contact angle test diagram of the upright graphene nanorods in Example 1 of the present invention;
[0051] Figure 9 The Raman spectra of the upright graphene nanorods in Example 1 and the upright graphene in Comparative Example 1 are shown (the Raman spectra of the upright graphene have been shifted upwards as a whole).
[0052] Figure 10 The XPS spectrum of the upright graphene nanorods in Example 1 of this invention;
[0053] Figure 11 The XPS spectrum of the upright graphene in Comparative Example 1 of this invention is shown.
[0054] Figure 12 The images show the Raman spectra of the upright graphene nanorods in Example 1 of this invention after adding R6G (Rhodamine 6G) solutions of different concentrations, and the relationship curves between the Raman spectral intensity and the R6G concentration.
[0055] Figure 13 The Raman spectra of the upright graphene nanorods in Example 1 of this invention after adding EB (erythrosine B) solutions of different concentrations, and the relationship curve between Raman spectral intensity and EB concentration;
[0056] Figure 14 The Raman spectra of the upright graphene nanorods in Example 1 of this invention after adding CRV (crystal violet) solutions of different concentrations, and the relationship curve between Raman spectral intensity and CRV concentration;
[0057] Figure 15 The image shows the IV curves of the upright graphene nanorods in Example 1 of this invention before and after the addition of CRV in the dark, and before and after the addition of CRV under 980nm illumination.
[0058] Figure 16 The photocurrent response curves of the upright graphene nanorods in Example 1 of this invention before and after CRV was added under 980nm light illumination are shown.
[0059] Figure 17 The noise curves of the upright graphene nanorods in Example 1 of this invention before and after the addition of CRV are shown. Detailed Implementation
[0060] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0061] Example 1:
[0062] This embodiment provides a method for preparing upright graphene nanorods, including the following steps:
[0063] Step 101: Place the substrate in the growth chamber and then evacuate the growth chamber.
[0064] Optionally, in this embodiment, the substrate is a 1cm×1cm silicon substrate, and the pressure after evacuation of the growth chamber is approximately 5Pa.
[0065] Step 102: Introduce 1 sccm of hydrogen and 10 sccm of argon into the growth chamber, while gradually heating the substrate to T1.
[0066] Wherein, 500℃≤T1≤600℃. Preferably, in this embodiment, T1=550℃.
[0067] Step 103: Once the substrate temperature reaches T1, turn off the hydrogen and argon gases and start introducing methane into the growth chamber. At the same time, turn on the radio frequency plasma source to begin the first growth of upright graphene on the substrate.
[0068] As a preferred method, during the first growth of upright graphene, the methane flow rate is 5 sccm-15 sccm, the power of the radio frequency plasma source is 150W-250W, and the growth time is 30min-90min.
[0069] Further preferably, during the first growth of upright graphene, the methane flow rate is 8 sccm-12 sccm, the power of the radio frequency plasma source is 180W-220W, and the growth time is 50min-70min.
[0070] Specifically, in this embodiment, during the first growth of upright graphene, the methane flow rate was 10 sccm, the power of the radio frequency plasma source was 200W, and the growth time was 60 min.
[0071] Step 104: After the first vertical graphene growth is completed, turn off the radio frequency plasma source and stop the introduction of methane into the growth chamber, and then heat the substrate to T2.
[0072] Where 620℃≤T2≤660℃. Preferably, in this embodiment, T2=650℃.
[0073] Step 105: Once the substrate temperature reaches T2, turn on the radio frequency plasma source again and introduce methane and ammonia into the growth chamber to grow upright graphene on the substrate for the second time, thereby obtaining upright graphene nanorods.
[0074] Preferably, during the second growth of upright graphene, the flow rate of methane is 5 sccm-15 sccm, the flow rate of ammonia is 0.5 sccm-5 sccm, the power of the radio frequency plasma source is 200W-300W, and the growth time is no more than 30 minutes.
[0075] Further preferably, during the second growth of upright graphene, the flow rate of methane is 8 sccm-12 sccm, the flow rate of ammonia is 0.5 sccm-2 sccm, the power of the radio frequency plasma source is 230W-270W, and the growth time is 10min-20min.
[0076] Specifically, in this embodiment, during the second growth of upright graphene, the flow rate of methane is 10 sccm, the flow rate of ammonia is 1 sccm, the power of the radio frequency plasma source is 250W, and the growth time is 15min.
[0077] Step 106: Stop introducing methane and ammonia into the growth chamber and stop heating the substrate. At the same time, introduce 10 sccm of argon gas to restore the pressure inside the growth chamber to atmospheric pressure. After the substrate and the upright graphene nanorods on it have cooled naturally to room temperature, remove them from the growth chamber.
[0078] Comparative Example 1:
[0079] This comparative example provides a method for preparing upright graphene, including the following steps:
[0080] Step 201: Place the substrate in the growth chamber and then evacuate the growth chamber. The substrate is a 1cm × 1cm silicon substrate, and the pressure after evacuation of the growth chamber is approximately 5Pa.
[0081] Step 202: Introduce 1 sccm of hydrogen and 10 sccm of argon into the growth chamber, while gradually heating the substrate to 550°C.
[0082] Step 203: Once the substrate temperature reaches 550℃, turn off the hydrogen and argon gases and begin introducing methane into the growth chamber. Simultaneously, turn on the radio frequency plasma source to begin growing upright graphene on the substrate. The methane flow rate is 10 sccm, the radio frequency plasma source power is 200W, and the growth time is 60 minutes.
[0083] Step 204: Stop introducing methane into the growth chamber and introduce 10 sccm of argon gas to restore the pressure inside the growth chamber to atmospheric pressure. Stop heating the substrate and remove it from the growth chamber after it has cooled naturally.
[0084] Comparative Example 2:
[0085] The difference between this comparative example and Example 1 is that T2 = 750℃, resulting in flower-like upright graphene nanorods instead of upright graphene. For the relevant test data of Comparative Example 2, please refer to the inventor's prior application 2023115486401.
[0086] By comparison Figure 1 and Figure 2 It can be observed that the second growth process of upright graphene in Example 1 effectively altered the morphology of the first-growth upright graphene, ultimately forming rod-shaped upright graphene instead of flower-like upright graphene. The length and width of the upright graphene nanorods are approximately 500 nm and 100 nm, respectively. Further comparison... Figure 2 and Figure 3 It can be observed that the upright graphene nanorods prepared in this embodiment have a high degree of morphological similarity to plant glands, thus proving that the upright graphene nanorods prepared in Example 1 exhibit a good biomimetic structure. Specifically, the upright graphene grown in the first stage in Example 1 can correspond to the main part of the plant gland, while the growth process of the second upright graphene can be compared to the secretory behavior of the plant gland. Finally, the second-grown upright graphene covers the surface of the first-grown upright graphene, ultimately forming upright graphene nanorods similar to plant glands.
[0087] Specifically, such as Figure 4 and Figure 5 As shown, the upright graphene nanorods in this embodiment exhibit vertical orientation characteristics on the substrate surface, with an average height of approximately 1.2 μm.
[0088] like Figure 6 As shown, the porosity of the upright graphene nanorods in this embodiment is approximately 89%, thus demonstrating that the upright graphene nanorods possess a high specific surface area. However, it is worth noting that the porosity of the upright graphene nanorods in Example 1 is slightly lower than the 90% porosity of the flower-like upright graphene in Comparative Example 2.
[0089] like Figure 7 As shown, the upright graphene nanorods in this embodiment exhibit high uniformity of electric field distribution, with the largest light absorption region located at the edge of the nanorods.
[0090] like Figure 8As shown, the water contact angle of the upright graphene nanorod surface is 130°, thus confirming that the upright graphene nanorods possess superhydrophobicity. Based on this characteristic, when the test liquid is dropped onto the surface of the upright graphene nanorods, the test liquid easily accumulates at local locations on the surface of the upright graphene nanorods, which in turn easily causes changes in the Raman spectrum of the upright graphene nanorods, thus facilitating the compositional analysis of the test liquid. However, it is worth noting that the water contact angle of the upright graphene nanorods in Example 1 is smaller than the 135° water contact angle of the flower-shaped upright graphene in Comparative Example 2, thus confirming that the hydrophobicity of the upright graphene nanorods is not as good as that of the flower-shaped upright graphene.
[0091] like Figure 9 As shown, the characteristic peaks of upright graphene in Comparative Example 1 are, in order, peak D (1350 cm⁻¹). -1 ), G peak (1580cm) -1 ) and 2D peak (2700cm) -1 In Example 1, the introduction of nitrogen atoms into the upright graphene nanorods caused changes in the crystallinity and order of the graphene. Coupling occurred between the nitrogen atoms and the graphene elastic layer, resulting in a red shift of the G peak of the upright graphene nanorods and a blue shift of the 2D peak.
[0092] like Figure 10 As shown, in Example 1, the three characteristic peaks in the C-1s high-resolution XPS spectrum of the upright graphene nanorods are located at 284.7 eV (C=C), 285.6 eV (C=N), and 286.8 eV (CN), respectively. In the N-1s high-resolution XPS spectrum, the three characteristic peaks are located at 397.5 eV (pyridine N), 401 eV (pyrrole N), and 404.5 eV (graphite N), respectively. Further analysis with… Figure 11 The comparison confirmed that although T2 in Example 1 was significantly lower than T2 in Comparative Example 2, N atoms still successfully entered the interior of the upright graphene lattice.
[0093] like Figure 12 As shown, in the Raman spectrum of upright graphene nanorods, at 1590 cm⁻¹... -1 and 1345cm -1 The Raman intensity at 1590 cm⁻¹ increases with increasing R₆G concentration. -1 There is a good linear relationship between the logarithm of the Raman intensity and the R6G concentration (R 2 =0.8398), based on 1590cm -1 The lower limit for R6G concentration detection using the logarithm of Raman intensity is 10. -11 M; 1345cm -1 There is a good linear relationship between the logarithm of the Raman intensity and the R6G concentration (R 2=0.9633), based on 1345cm -1 The lower limit for R6G concentration detection using the logarithm of Raman intensity is 10. -11 M. In other words, the lower limit of detection for R6G concentration by the upright graphene nanorods in Example 1 is 10. -11 M. In Comparative Example 2, the detection limit for R6G concentration in the flower-like upright graphene was also 10. -11 M.
[0094] Based on this, this embodiment can further provide two methods for detecting the concentration of Rhodamine 6G.
[0095] One method for detecting the concentration of rhodamine 6G includes the following steps:
[0096] Step 301: Obtain the Raman spectrum of upright graphene nanorods at 1345 cm⁻¹ -1 Intensity a at point 1345 ;
[0097] Step 302: The solution to be tested is dropped onto the upright graphene nanorods, and the Raman spectrum of the upright graphene nanorods at 1345 cm⁻¹ is obtained again. -1 Intensity A at point 1345 ;
[0098] Step 303: At least based on a 1345 and A 1345 Determine the concentration of Rhodamine 6G in the test solution.
[0099] Another method for detecting rhodamine 6G concentration includes the following steps:
[0100] Step 401: Obtain the 1590 cm⁻¹ Raman spectrum of upright graphene nanorods. -1 Intensity a at point 1590 ;
[0101] Step 402: Add the test solution to the upright graphene nanorods and obtain the Raman spectrum of the upright graphene nanorods at 1590 cm⁻¹ again. -1 Intensity A at point 1590 ;
[0102] Step 403: At least based on a 1590 and A 1590 Determine the concentration of Rhodamine 6G in the test solution.
[0103] like Figure 13 As shown, in the Raman spectrum of upright graphene nanorods, 1610 cm⁻¹ -1 and 1360cm -1 The Raman intensity at 1610 cm⁻¹ increases with increasing EB concentration. -1There is a good linear relationship between the logarithm of the Raman intensity and the EB concentration (R0). 2 =0.9743), based on 1610cm -1 The lower limit for EB concentration detection using the logarithm of Raman intensity is 10. -11 M; 1360cm -1 There is a good linear relationship between the logarithm of the Raman intensity and the EB concentration (R0). 2 =0.9630), based on 1360cm -1 The lower limit for EB concentration detection using the logarithm of Raman intensity is 10. -11 M. In other words, the lower limit of detection for EB concentration by the upright graphene nanorods in Example 1 is 10. -11 M. In Comparative Example 2, the detection limit for EB concentration by the flower-like upright graphene was also 10. -11 M.
[0104] Based on this, this embodiment can further provide two methods for detecting erythrosine B concentration.
[0105] One method for detecting erythrosine B concentration includes the following steps:
[0106] Step 501: Obtain the 1360 cm⁻¹ Raman spectrum of upright graphene nanorods. -1 Intensity a at point 1360 ;
[0107] Step 502: Add the test solution to the upright graphene nanorods and obtain the Raman spectrum of the upright graphene nanorods at 1360 cm⁻¹ again. -1 Intensity A at point 1360 ;
[0108] Step 503: At least based on a 1360 and A 1360 Determine the concentration of erythromycin B in the test solution.
[0109] Another method for detecting erythrosine B concentration includes the following steps:
[0110] Step 601: Obtain the 1610 cm⁻¹ Raman spectrum of upright graphene nanorods. -1 Intensity a at point 1610 ;
[0111] Step 602: Add the test solution dropwise onto the upright graphene nanorods, and obtain the 1610 cm⁻¹ Raman spectrum of the upright graphene nanorods again. -1 Intensity A at point 1610 ;
[0112] Step 603: At least based on a 1610 and A1610 Determine the concentration of erythromycin B in the test solution.
[0113] like Figure 14 As shown, in the Raman spectrum of upright graphene nanorods, at 1355 cm⁻¹... -1 and 1590cm -1 The Raman intensity at 1355 cm⁻¹ increases with increasing CRV concentration. -1 There is a good linear relationship between the logarithm of the Raman intensity and the CRV concentration (R0). 2 =0.9403), based on 1355cm -1 The lower limit of concentration for CRV concentration detection using the logarithm of Raman intensity is 10. -10 M; 1590cm -1 There is a good linear relationship between the logarithm of the Raman intensity and the CRV concentration (R0). 2 =0.9418), based on 1590cm -1 The lower limit of concentration for CRV concentration detection using the logarithm of Raman intensity is 10. -10 M. In other words, the lower limit of detection for CRV concentration by the upright graphene nanorods in Example 1 is 10. -10 M. In Comparative Example 2, the detection limit for CRV concentration using flower-like upright graphene was only 10. -8 M.
[0114] Based on this, this embodiment can further provide two methods for detecting crystal violet concentration.
[0115] One method for detecting crystal violet concentration includes the following steps:
[0116] Step 701: Obtain the 1355 cm⁻¹ Raman spectrum of upright graphene nanorods. -1 Intensity a at point 1355 ;
[0117] Step 701: Add the test solution to the upright graphene nanorods and obtain the Raman spectrum of the upright graphene nanorods at 1355 cm⁻¹ again. -1 Intensity A at point 1355 ;
[0118] Step 701: At least based on a 1355 and A 1355 Determine the concentration of crystal violet in the solution to be tested.
[0119] Another method for detecting crystal violet concentration includes the following steps:
[0120] Step 801: Obtain the 1590 cm⁻¹ Raman spectrum of upright graphene nanorods. -1 Intensity a at point 1590;
[0121] Step 802: Add the test solution to the upright graphene nanorods and obtain the Raman spectrum of the upright graphene nanorods at 1590 cm⁻¹ again. -1 Intensity A at point 1590 ;
[0122] Step 803: At least based on a 1590 and A 1590 Determine the concentration of crystal violet in the solution to be tested.
[0123] based on Figure 6 , Figure 8 , Figures 12-14 It is evident that although upright graphene nanorods have lower porosity and hydrophobicity than flower-shaped upright graphene, their ability to detect the concentrations of R6G and EB is comparable to that of flower-shaped upright graphene, and their ability to detect the concentration of CRV is even superior. In other words, upright graphene nanorods not only have a lower preparation temperature than flower-shaped upright graphene, thus resulting in lower production costs, but also achieve a further improvement in SERS detection capabilities compared to flower-shaped upright graphene.
[0124] To investigate why upright graphene nanorods exhibit superior SERS detection capabilities compared to flower-shaped upright graphene, we first referred to... Figures 15-17 The photocurrent and dark current of upright graphene nanorods significantly increased after the addition of CRV (carrier volatile organic compound), because CRV increases the effective lifetime of photogenerated carriers, thereby slowing down the photocurrent response speed of the upright graphene nanorods. Furthermore, the noise current power spectral density of upright graphene nanorods significantly increased after CRV adsorption, indicating that CRV increases the random fluctuations of carrier transport during the upright graphene nanorods. These results suggest that there are numerous defects at the edges of the upright graphene nanorods. See again. Figure 7 Compared to flower-shaped upright graphene, upright graphene nanorods have more abundant tips and edges. This allows them to achieve a higher specific surface area despite a lower porosity compared to flower-shaped upright graphene. Furthermore, the numerous defects at the edges of the upright graphene nanorods further enhance this localization. When the CRV (Catalyst Radiation Reflector) comes into contact with these localized electric fields, the Raman scattering signal increases exponentially. Therefore, the detection mechanisms of upright graphene nanorods and flower-shaped upright graphene differ to some extent in SERS (Sensitive Earth Reflection) analysis.
[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0126] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A method of fabricating an upright graphene nanorod, the method comprising: providing a graphene sheet; providing a substrate; and providing a catalyst nanoparticle on the substrate; and positioning the catalyst nanoparticle on the graphene sheet. The preparation method comprises the following steps: putting a substrate into a growth chamber, and then heating the substrate to T1, wherein 500℃≤T1≤600℃; turning on a radio frequency plasma source, and introducing methane into the growth chamber to grow vertical graphene on the substrate for the first time; turning off the radio frequency plasma source, and stopping the introduction of methane into the growth chamber; heating the substrate to T2, wherein 620℃≤T2≤660℃; turning on the radio frequency plasma source again, introducing methane and ammonia into the growth chamber to grow vertical graphene on the substrate for the second time, and obtaining vertical graphene nanorods.
2. The method for preparing upright graphene nanorods according to claim 1, characterized in that, In the growth of the vertical graphene for the first time, the flow rate of methane is 8-12sccm, the power of the radio frequency plasma source is 180-220W, and the growth time is 50-70min.
3. The method for preparing upright graphene nanorods according to claim 1, characterized in that, In the growth of the vertical graphene for the second time, the flow rate of methane is 8-12sccm, the flow rate of ammonia is 0.5-2sccm, the power of the radio frequency plasma source is 230-270W, and the growth time is 10-20min.
4. An upright graphene nanorod, characterized by, The vertical graphene nanorods are prepared by the preparation method of claim 1 or 2 or 3.
5. The vertical graphene nanorods of claim 4 are applied in the detection of rhodamine 6G.
6. A method for detecting the concentration of rhodamine 6G, characterized by, The preparation method comprises the following steps: Obtaining the intensity a at 1345 cm -1 in the Raman spectrum of the standing graphene nanorod as claimed in claim 4 1345 ; adding the solution to be tested to the standing graphene nanorod, and again acquiring the intensity A of the 1345 cm -1 place in the Raman spectrum of the standing graphene nanorod 1345 ; At least based on a 1345 and A 1345 The concentration of rhodamine 6G in the solution to be tested is determined.
7. A method for detecting the concentration of rhodamine 6G, characterized by, The preparation method comprises the following steps: Obtaining the intensity a at 1590 cm -1 in the Raman spectrum of the standing graphene nanorod as claimed in claim 4 1590 ; adding the solution to be tested to the standing graphene nanorod, and again acquiring the intensity A of the 1590 cm -1 in the Raman spectrum of the standing graphene nanorod 1590 ; At least based on a 1590 and A 1590 The concentration of rhodamine 6G in the solution to be measured is determined.
8. The vertical graphene nanorods of claim 4 are applied in the detection of erythrosin B.
9. A method for detecting the concentration of erythrosine B, characterized by, The preparation method comprises the following steps: Obtaining the intensity a at 1360 cm -1 in the Raman spectrum of the standing graphene nanorod as claimed in claim 4 1360 ; adding the solution to be tested to the standing graphene nanorod, and again acquiring the intensity A of the 1360 cm -1 in the Raman spectrum of the standing graphene nanorod 1360 ; At least based on a 1360 and A 1360 The concentration of erythrosine B in the solution to be measured is determined.
10. A method for detecting the concentration of erythrosine B, characterized by, The preparation method comprises the following steps: Obtaining the intensity a at 1610 cm -1 in the Raman spectrum of the standing graphene nanorod as claimed in claim 4 1610 ; adding the solution to be tested to the standing graphene nanorod, and again acquiring the intensity A of the 1610 cm -1 in the Raman spectrum of the standing graphene nanorod 1610 ; At least based on a 1610 and A 1610 The concentration of erythrosine B in the solution to be measured is determined.
11. The vertical graphene nanorods of claim 4 are applied in the detection of crystal violet.
12. A method for detecting a concentration of crystal violet, characterized by, The preparation method comprises the following steps: Obtaining the intensity a at 1355 cm -1 in the Raman spectrum of the standing graphene nanorod as claimed in claim 4 1355 ; adding the solution to be tested to the standing graphene nanorod, and again acquiring the intensity A of the 1355 cm -1 peak in the Raman spectrum of the standing graphene nanorod 1355 ; at least based on a 1355 and A 1355 The concentration of crystal violet in the solution to be measured is determined.
13. A method for detecting a concentration of crystal violet, characterized by, The preparation method comprises the following steps: Obtaining the intensity a at 1590 cm -1 in the Raman spectrum of the standing graphene nanorod as claimed in claim 4 1590 ; adding the solution to be tested to the standing graphene nanorod, and again acquiring the intensity A of the 1590 cm -1 in the Raman spectrum of the standing graphene nanorod 1590 ; at least based on a 1590 and A 1590 The concentration of crystal violet in the solution to be measured was determined.