Nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor as well as preparation method and application thereof

Abstract

The invention relates to the technical field of corrosion inhibitors, in particular to a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor and a preparation method and application thereof. According to the specific technical scheme, according to the preparation method of the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor, a mixed system of L-alanine or a derivative thereof, boric acid, polydimethylsilane and a solvent is subjected to a reaction for 8-12 h at the temperature of 180-250 DEG C through a hydrothermal synthesis method, and the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor is obtained. The corrosion inhibitor provided by the invention has excellent corrosion resistance and protection capability on metal, and the preparation method has the advantages of greenness, environmental protection, convenience in operation, low cost and the like, and can be applied to the industries such as metal, chemical industry, petroleum, ships, traffic, nuclear industry and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion inhibitors, and in particular to a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor, a preparation method thereof, and applications thereof. Background Art

[0002] Metal corrosion is a ubiquitous phenomenon in industrial production and everyday life, particularly in the petrochemical, marine engineering, and nuclear industries. Corrosion not only causes significant economic losses but can also lead to serious safety incidents. Statistics show that global economic losses from metal corrosion reach trillions of dollars annually. Therefore, the development of efficient and environmentally friendly corrosion inhibitors has become a key research area in addressing metal corrosion.

[0003] Traditional corrosion inhibitors primarily include phosphorus-based, chromate-based, and organic amine compounds. While these inhibitors can inhibit metal corrosion to a certain extent, their use presents numerous challenges. For example, phosphorus-based inhibitors can easily lead to eutrophication of water bodies, chromate-based inhibitors are highly toxic, and organic amine-based inhibitors can cause secondary environmental pollution. Furthermore, the effectiveness of traditional inhibitors is significantly affected by water quality and they perform poorly in highly concentrated acidic or alkaline environments. Therefore, the development of a new, highly effective, environmentally friendly, and widely adaptable corrosion inhibitor is a pressing need in current research.

[0004] In recent years, nanomaterials have demonstrated tremendous potential in corrosion inhibition due to their unique physical and chemical properties. Graphene quantum dots, a novel carbon-based nanomaterial, possess high specific surface area, excellent electrical conductivity, good chemical stability, and a rich array of surface functional groups. These properties enable them to form a dense protective film on metal surfaces, effectively blocking the erosion of corrosive media. Furthermore, graphene quantum dots exhibit excellent dispersibility and biocompatibility, making them adaptable to a variety of complex environments while remaining environmentally friendly.

[0005] In summary, graphene quantum dots, as a new type of corrosion inhibitor, not only effectively address the limitations of traditional corrosion inhibitors but also offer advantages such as high efficiency, environmental friendliness, and wide adaptability. Therefore, the development of graphene quantum dot-based corrosion inhibitors has significant scientific significance and application value, and is expected to bring new breakthroughs to the field of metal corrosion protection. Summary of the Invention

[0006] In response to the deficiencies of the prior art, the present invention provides a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor and a preparation method and application thereof.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] The present invention discloses a preparation method of nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor, which comprises subjecting L-alanine or its derivatives, boric acid, polydimethylsilane and a solvent to a hydrothermal reaction at 180-250° C. for 8-12 hours to obtain the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor.

[0009] Preferably, the L-alanine derivative includes L-alanine methyl ester hydrochloride and / or N-α-Fmoc-L-alanine, and the solvent includes water and / or acid, or water and / or base.

[0010] Preferably, the mass ratio of boric acid to L-alanine or its derivatives is 3:100-25:100; the mass ratio of polydimethylsilane to L-alanine or its derivatives is 3:100-25:100.

[0011] Preferably, after the hydrothermal reaction is completed, the obtained solution is stirred, ultrasonicated, filtered, centrifuged, dialyzed, and vacuum dried, wherein the stirring time is 15-25 min; the ultrasonic treatment time is 15-25 min; the centrifugal speed is 8000-16000 r / min; the molecular weight of the dialysis bag used in the dialysis treatment is 2-5 KD; the drying temperature is 65-85 ° C, and the time is 24-72 h.

[0012] Correspondingly, the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor prepared by the preparation method.

[0013] Preferably, the constituent elements of the corrosion inhibitor include C, H, O, N, B and Si, and the size of the corrosion inhibitor is 2-25 nm.

[0014] Preferably, the solubility of the corrosion inhibitor in water is 15-180 mg / mL.

[0015] Correspondingly, the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor prepared by the preparation method is used in corrosion protection of metal substrate surfaces.

[0016] Preferably, the metal substrate includes any one of steel, copper, iron and alloys thereof.

[0017] Preferably, the surface of the metal substrate is immersed in a solution containing nitrogen, phosphorus and fluorine ternary doped carbon quantum dots corrosion inhibitor, thereby achieving protection of the metal substrate.

[0018] The present invention has the following beneficial effects:

[0019] (1) The method for preparing a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor with high protection efficiency provided by the present invention through hydrothermal synthesis has the advantages of easy operation, low cost and environmental protection.

[0020] (2) The nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor provided by the present invention has excellent water solubility and corrosion inhibition. The active sites in the corrosion inhibitor are cross-linked and adsorbed to the metal surface, which increases the coverage of the metal surface and thus reduces the corrosion rate of the metal; at the same time, the good water solubility effectively improves the dispersibility of the corrosion inhibitor in an aqueous environment.

[0021] (3) The corrosion inhibitor prepared by the present invention through hydrothermal reaction of L-alanine or its derivatives, boric acid and polydimethylsilane has good water solubility and excellent corrosion resistance. It can be used in the metal, chemical, petroleum, electric power, papermaking, oil refining, shipbuilding, storage, transportation and other industries. It is particularly expected to be used in large-scale equipment such as chemical equipment, metal equipment, petroleum, offshore platforms, etc. The corrosion inhibitor of the present invention is used on the surface of the metal substrate, which can also increase the service life of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a TEM image of the corrosion inhibitor prepared in Example 1. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0025] The present invention discloses a method for preparing a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. The specific steps are: subjecting a mixed system of L-alanine or its derivatives, boric acid, polydimethylsilane, and a solvent to a reaction at 180-250°C for 8-12 hours by a hydrothermal synthesis method; after the hydrothermal reaction is completed, the obtained solution is stirred, ultrasonicated, filtered, centrifuged, dialyzed, and dried to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor with excellent protective capabilities. The L-alanine derivatives include but are not limited to L-alanine methyl ester hydrochloride and / or N-α-Fmoc-L-alanine. The solvent includes but is not limited to water and / or an acid, or water and / or a base.

[0026] Specifically, L-alanine or its derivatives, boric acid, and polydimethylsilane are dissolved in deionized water, and then transferred to a high-temperature reactor and reacted at a temperature of 180-250°C for 8-12 hours. After the hydrothermal reaction is completed, the obtained solution is stirred, ultrasonicated, filtered, centrifuged, dialyzed, and dried to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor.

[0027] Furthermore, the stirring treatment lasts for 15-25 minutes, the ultrasonic treatment lasts for 15-25 minutes, the filtration treatment uses qualitative filter paper for vacuum filtration, and the number of filtration treatments is 3-6 times. The centrifugal treatment speed is 8000-16000 r / min, the dialysis treatment uses a dialysis bag with a molecular weight of 2-5 kD, and the drying treatment temperature is 65-85°C and the drying time is 24-72 hours.

[0028] Furthermore, the mass ratio of the boric acid to L-alanine or its derivatives is 3:100-25:100; the mass ratio of polydimethylsilane to L-alanine or its derivatives is 3:100-25:100.

[0029] The nitrogen-boron-silicon cross-linked graphene quantum dot corrosion inhibitor prepared by the present invention comprises elements including C, H, O, N, B, and Si. The size of the corrosion inhibitor is 2-25 nm and the corrosion inhibitor has excellent dispersibility in an aqueous environment. The solubility of the corrosion inhibitor in water is 15-180 mg / mL, indicating that the nitrogen-boron-silicon cross-linked graphene quantum dot corrosion inhibitor has excellent water solubility.

[0030] The nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor prepared by the present invention is used in the corrosion protection of the metal substrate surface. When used, the metal substrate surface is immersed in a solution of the prepared nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor, thereby achieving protection of the metal substrate.

[0031] The metal substrate includes, but is not limited to, any one of steel, copper, iron, and alloys thereof, and can be used in the petroleum industry, marine industry, defense industry, machinery industry, papermaking industry, transportation platforms, and the like. The nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor prepared by the present invention can be used in the fields of steel, chemical industry, petroleum, electricity, papermaking, oil refining, shipping, storage, transportation, and the like.

[0032] Furthermore, after the metal substrate is immersed in the HCl solution of the nitrogen-boron-silicon cross-linked graphene quantum dots for 24 hours, the corrosion current density is as low as 10 -6 A / cm 2 , showing excellent corrosion resistance. Compared with the solution without adding corrosion inhibitor, the corrosion current density decreased by 2 orders of magnitude.

[0033] Furthermore, the corrosion current density of the metal substrate was as low as 10 after being immersed in the NaCl solution of the nitrogen-boron-silicon cross-linked doped graphene quantum dots for 24 hours. -6 A / cm 2, showing excellent corrosion resistance. Compared with the solution without adding corrosion inhibitor, the corrosion current density decreased by 2 orders of magnitude.

[0034] Furthermore, after the metal substrate is immersed in the NaOH solution of the nitrogen-boron-silicon cross-linked graphene quantum dots for 24 hours, the corrosion current density is as low as 10 -5 -10 -6 A / cm 2 , showing excellent corrosion resistance. Compared with the solution without adding corrosion inhibitor, the corrosion current density decreased by 1-2 orders of magnitude.

[0035] In summary, the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor provided by the present invention has excellent water solubility and corrosion resistance. The active sites in the corrosion inhibitor are adsorbed and combined with the metal surface, which increases the coverage of the metal surface and thus reduces the corrosion rate of the metal; at the same time, the good water solubility effectively improves the dispersibility of the corrosion inhibitor in an aqueous environment.

[0036] The corrosion inhibitor prepared by the hydrothermal synthesis method of the present invention has good water solubility and excellent anti-corrosion performance. It can be used in industries such as steel, chemical industry, petroleum, electric power, papermaking, oil refining, shipbuilding, storage, and transportation. It is particularly expected to be used in large-scale equipment such as metal equipment, chemical equipment, steel, petroleum, and offshore platforms. The corrosion inhibitor of the present invention is used on the surface of a metal substrate, which can also increase the service life of the substrate.

[0037] The present invention will be further described below with reference to specific embodiments.

[0038] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0039] Comparative Example 1

[0040] First, the Q235 carbon steel substrate was degreased. Then, a copper wire was soldered to the carbon steel surface and sealed in AB glue, leaving only a 1cm×1cm test surface exposed. The working surface was then polished for 20 minutes using 400#, 800#, 1200#, and 1500# sandpaper, respectively. Finally, it was rinsed with ethanol and dried. After treatment, the carbon steel substrate was used as the working electrode, a saturated calomel electrode was used as the reference electrode, and a platinum sheet was used as the counter electrode for electrochemical testing. After immersion in 1M HCl solution for 24 hours, the corrosion current density was 2.1×10 -4 A / cm 2 .

[0041] Comparative Example 2

[0042] First, the copper substrate was degreased. Then, a copper wire was soldered to the copper surface and sealed in AB glue, leaving only a 1cm×1cm test surface exposed. The working surface was then polished for 20 minutes using 400#, 800#, 1200#, and 1500# sandpaper, respectively. Finally, it was rinsed with ethanol and dried. After treatment, the copper substrate was used as the working electrode, a saturated calomel electrode was used as the reference electrode, and a platinum sheet was used as the counter electrode for electrochemical testing. After immersion in 1M HCl solution for 24 hours, the corrosion current density was 2.8×10 -4 A / cm 2 .

[0043] Comparative Example 3

[0044] First, the Q235 carbon steel substrate was degreased. A copper wire was then soldered to the carbon steel surface and sealed in AB glue, leaving only a 1cm×1cm test surface exposed. The working surface was then polished for 20 minutes using 400#, 800#, 1200#, and 1500# sandpaper, respectively. Finally, it was rinsed with ethanol and dried. After treatment, the carbon steel substrate was used as the working electrode, a saturated calomel electrode was used as the reference electrode, and a platinum sheet was used as the counter electrode for electrochemical testing. After immersion in a 3.5% NaCl solution for 24 hours, the corrosion current density was 1.2×10 -4 A / cm 2 .

[0045] Comparative Example 4

[0046] First, the Q235 carbon steel substrate was degreased. Then, a copper wire was soldered to the carbon steel surface and sealed in AB glue, leaving only a 1cm×1cm test surface exposed. The working surface was then polished for 20 minutes using 400#, 800#, 1200#, and 1500# sandpaper, respectively. Finally, it was rinsed with ethanol and dried. After treatment, the carbon steel substrate was used as the working electrode, a saturated calomel electrode was used as the reference electrode, and a platinum sheet was used as the counter electrode for electrochemical testing. After immersion in 1M NaOH solution for 24 hours, the corrosion current density was 3.6×10 -4 A / cm 2 .

[0047] Comparative Example 5

[0048] 2g of L-alanine was dissolved in 60mL of deionized water and then transferred to a reactor. The heating temperature was set to 210°C for 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min. It was then filtered and centrifuged at a speed of 8000r / min during the centrifugation process. It was then dialyzed and the molecular weight of the dialysis bag was 2KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-doped graphene-based quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 1 below. The results show that nitrogen-doped graphene-based quantum dots have a certain inhibitory effect on metal corrosion.

[0049] Table 1 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0050] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[8.1×10 -5 ]]> <![CDATA[6.4×10 -5 ]]> <![CDATA[5.3×10 -5 ]]> <![CDATA[4.7×10 -5 ]]> Corrosion inhibition efficiency (%) 61 70 75 78

[0051] Comparative Example 6

[0052] 2g L-alanine and 0.1g boric acid were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min. It was then filtered and centrifuged at a speed of 8000r / min during the centrifugation process. It was then dialyzed and the molecular weight of the dialysis bag was 2KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-boron-doped graphene-based carbon quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 2 below. The results show that boron doping can further improve the corrosion inhibition efficiency of nitrogen-doped graphene-based quantum dots.

[0053] Table 2 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0054] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[5.8×10 -5 ]]> <![CDATA[5.4×10 -5 ]]> <![CDATA[4.6×10 -5 ]]> <![CDATA[3.5×10 -5 ]]> Corrosion inhibition efficiency (%) 72 74 78 83

[0055] Comparative Example 7

[0056] 2g L-alanine and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min. It was then filtered and centrifuged at a speed of 8000r / min during the centrifugation process. It was then dialyzed and the molecular weight of the dialysis bag was 2KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-silicon-doped graphene-based carbon quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 3 below. The results show that silicon doping can further improve the corrosion inhibition efficiency of nitrogen-doped graphene-based quantum dots.

[0057] Table 3 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0058] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[5.3×10 -5 ]]> <![CDATA[4.1×10 -5 ]]> <![CDATA[3.6×10 -5 ]]> <![CDATA[2.9×10 -5 ]]> Corrosion inhibition efficiency (%) 75 80 83 86

[0059] Example 1

[0060] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water, and then transferred to a reactor. The heating temperature was set to 210℃ and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 24h at a temperature of 65℃ to obtain nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. The high-resolution morphology of the corrosion inhibitor is shown in FIG. Figure 1 As shown, the results show that the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor has excellent dispersibility and a size of about 2-6 nm. Subsequently, a certain amount of corrosion inhibitor was added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400 mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24 hours, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 4. The results show that the corrosion current density was reduced by 2 orders of magnitude compared with Comparative Example 1, and by 1 order of magnitude compared with Comparative Examples 5 and 6.

[0061] Table 4 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0062] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[5.6×10 -6 ]]> <![CDATA[4.8×10 -6 ]]> <![CDATA[3.2×10 -6 ]]> <![CDATA[1.7×10 -6 ]]> Corrosion inhibition efficiency (%) 97 98 98 99

[0063] Example 2

[0064] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 180°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialysate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 5.

[0065] Table 5 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0066] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[6.8×10 -6 ]]> <![CDATA[5.6×10 -6 ]]> <![CDATA[4.4×10 -6 ]]> <![CDATA[2.9×10 -6 ]]> Corrosion inhibition efficiency (%) 97 97 98 99

[0067] Example 3

[0068] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 250°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialysate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 6.

[0069] Table 6 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0070] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[8.2×10 -6 ]]> <![CDATA[7.3×10 -6 ]]> <![CDATA[6.6×10 -6 ]]> <![CDATA[4.5×10 -6 ]]> Corrosion inhibition efficiency (%) 96 97 97 98

[0071] Example 4

[0072] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 8h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialysate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 7.

[0073] Table 7 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0074] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[6.6×10 -6 ]]> <![CDATA[4.3×10 -6 ]]> <![CDATA[3.7×10 -6 ]]> <![CDATA[2.8×10 -6 ]]> Corrosion inhibition efficiency (%) 97 98 98 99

[0075] Example 5

[0076] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 12h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a ternary doped carbon quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 8.

[0077] Table 8 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0078] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[7.7×10 -6 ]]> <![CDATA[6.9×10 -6 ]]> <![CDATA[5.8×10 -6 ]]> <![CDATA[4.0×10 -6 ]]> Corrosion inhibition efficiency (%) 96 97 97 98

[0079] Example 6

[0080] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and subsequently transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialysate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 3.5% NaCl solution to prepare a corrosion inhibitor solution with a concentration of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 2 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 9.

[0081] Table 9 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0082] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[4.3×10 -6 ]]> <![CDATA[3.2×10 -6 ]]> <![CDATA[2.8×10 -6 ]]> <![CDATA[1.2×10 -6 ]]> Corrosion inhibition efficiency (%) 98 98 99 98

[0083] Example 7

[0084] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialysate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M NaOH solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 3 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 10. It can be seen from Example 6 that the corrosion inhibitor solution exhibits excellent corrosion inhibition in a variety of environmental media.

[0085] Table 10 Corrosion current density and corrosion inhibition efficiency of corrosion inhibitor solutions with different concentrations

[0086] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[1.02×10 -5 ]]> <![CDATA[8.3×10 -6 ]]> <![CDATA[5.8×10 -6 ]]> <![CDATA[3.9×10 -6 ]]> Corrosion inhibition efficiency (%) 95 96 97 98

[0087] Example 8

[0088] 2g L-alanine, 0.6g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a ternary doped carbon quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare an inhibitor solution with a concentration of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 11.

[0089] Table 11 Corrosion current density and corrosion inhibition efficiency of corrosion inhibitor solutions with different concentrations

[0090] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[8.8×10 -6 ]]> <![CDATA[6.7×10 -6 ]]> <![CDATA[5.4×10 -6 ]]> <![CDATA[4.7×10 -6 ]]> Corrosion inhibition efficiency (%) 96 97 97 98

[0091] Example 9

[0092] 2g L-alanine, 0.1g boric acid and 0.6g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 15min and then ultrasonicated for 15min, then filtered and centrifuged. The speed during the centrifugation was 8000r / min, and then dialyzed. The molecular weight of the dialysis bag was 2KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 24h at 65°C to obtain a ternary doped carbon quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare an inhibitor solution with a concentration of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 1 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 12. Combining the comparative examples 1 and 8, it can be seen that excessive doping with boron or silicon will lead to a decrease in the corrosion inhibition effect, but the overall effect remains at a relatively high level (above 96%).

[0093] Table 12 Corrosion current density and corrosion inhibition efficiency of corrosion inhibitor solutions with different concentrations

[0094] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[7.3×10 -6 ]]> <![CDATA[5.7×10 -6 ]]> <![CDATA[4.8×10 -6 ]]> <![CDATA[3.5×10 -6 ]]> Corrosion inhibition efficiency (%) 97 97 98 98

[0095] Example 10

[0096] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 25min and then ultrasonicated for 25min, then filtered and centrifuged. The speed during the centrifugation was 16000r / min, and then dialyzed. The molecular weight of the dialysis bag was 5KD. Finally, the dialysate was placed in a vacuum drying oven and dried for 72h at 85°C to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 2 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 13.

[0097] Table 13 Corrosion current density and corrosion inhibition efficiency of different concentrations of corrosion inhibitor solutions

[0098] Corrosion inhibitor solution concentration (mg / L) 100 200 300 400 <![CDATA[Corrosion current density (A / cm 2 )]]> <![CDATA[6.0×10 -6 ]]> <![CDATA[5.1×10 -6 ]]> <![CDATA[3.7×10 -6 ]]> <![CDATA[2.2×10 -6 ]]> Corrosion inhibition efficiency (%) 97 98 98 99

[0099] Example 11

[0100] 2g L-alanine, 0.1g boric acid and 0.2g polydimethylsiloxane were dissolved in 60mL deionized water and then transferred to a reactor. The heating temperature was set to 210°C and the heating time was 10h. After the reaction was completed, the solution was stirred for 20min and then ultrasonicated for 20min, then filtered and centrifuged. The speed during the centrifugation was 12000r / min, and then dialyzed. The molecular weight of the dialysis bag was 3KD. Finally, the dialyzate was placed in a vacuum drying oven and dried for 360h at 75°C to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor. A certain amount of corrosion inhibitor was then added to a 1M HCl solution to prepare corrosion inhibitor solutions with concentrations of 100, 200, 300, and 400mg / L. The electrode prepared in Comparative Example 2 was placed in the above solution for electrochemical measurement. After soaking for 24h, the corrosion current density and corrosion inhibition efficiency finally obtained are shown in Table 14. In combination with Example 10, it was found that after adding the above corrosion inhibitor, the corrosion current density of copper in an HCl environment was reduced by 2 orders of magnitude, and the corrosion inhibition efficiency reached an extremely high level.

[0101] Table 14 Corrosion current density and corrosion inhibition efficiency of corrosion inhibitor solutions with different concentrations

[0102]

[0103]

[0104] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor, characterized in that: L-alanine or its derivatives, boric acid, polydimethylsilane and a solvent are hydrothermally reacted at 180-250° C. for 8-12 hours to obtain a nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor.

2. The preparation method according to claim 1, wherein: The L-alanine derivatives include L-alanine methyl ester hydrochloride and / or N-α-Fmoc-L-alanine, and the solvent includes water and / or acid, or water and / or base.

3. The preparation method according to claim 1, wherein: The mass ratio of the boric acid to L-alanine or its derivatives is 3:100-25:100; the mass ratio of polydimethylsilane to L-alanine or its derivatives is 3:100-25:

100.

4. The preparation method according to claim 1, wherein: After the hydrothermal reaction is completed, the obtained solution is stirred, ultrasonicated, filtered, centrifuged, dialyzed, and vacuum dried. The stirring time is 15-25 minutes; the ultrasonic treatment time is 15-25 minutes; the centrifugal speed is 8000-16000 r / min; the molecular weight of the dialysis bag used in the dialysis treatment is 2-5KD; the temperature of the drying treatment is 65-85°C and the time is 24-72 hours.

5. The nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor prepared by the preparation method according to any one of claims 1 to 4.

6. The nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor according to claim 5, characterized in that: The size of the corrosion inhibitor is 2-25 nm.

7. The nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor according to claim 5, characterized in that: The solubility of the corrosion inhibitor in water is 15-180 mg / mL.

8. Use of the nitrogen-boron-silicon cross-linked doped graphene quantum dot corrosion inhibitor prepared by the preparation method according to any one of claims 1 to 4 in corrosion protection of metal substrate surfaces.

9. The use according to claim 8, characterized in that: The metal substrate includes any one of steel, copper, iron and alloys thereof.

10. The use according to claim 8 or 9, characterized in that: The surface of the metal substrate is immersed in a solution containing nitrogen, phosphorus and fluorine ternary doped carbon quantum dot corrosion inhibitor.

Images