CN115321581A - Photoresponse type cuprous oxide anti-fouling agent and preparation method thereof - Google Patents

Abstract

The invention discloses a photoresponse type cuprous oxide antifouling agent and a preparation method thereof, wherein the photoresponse type cuprous oxide antifouling agent comprises cuprous oxide truncated octahedral micro-nano particles with special crystal faces exposed, each cuprous oxide micro-nano particle is formed by closing 6 (100) crystal faces and 8 (111) crystal faces, each (111) crystal face is adjacent to 3 (100) crystal faces, 36 edges and 24 vertexes are formed in total, the particle size distribution is 0.5-2 mu m, and the cuprous oxide micro-nano particles are prepared through a surfactant mediated wet chemical reduction strategy. Under the sunlight irradiation environment, cuprous oxide particles can rapidly separate surface photocarrier pairs (electron-hole, e) by virtue of the energy level difference between the (111) crystal planes and the (100) crystal planes ^‑ ‑h ⁺ ) Not only inhibiting photooxidation reaction of photogenerated cavity, but also continuously catalyzing dissolved oxygen (O) in seawater ₂ ) Water (H) ₂ O) and hydroxide ion (OH) ^‑ ) Etc. to generate oxyanion (. O) ₂ ^‑ ) And hydroxyl free radical (HO), and the like, so as to achieve the protection effect of killing fouling organisms.

Description

A light-responsive cuprous oxide antifouling agent and preparation method thereof

technical field

The invention relates to the technical field of marine antifouling, in particular to a light-responsive cuprous oxide antifouling agent and a preparation method thereof.

Background technique

Coating antifouling coatings on the surface of ships is the most effective technical solution to solve the problem of marine biofouling. Cuprous oxide, which has broad-spectrum biocidal activity, is generally used as the main antifouling agent. The waterline between the ship's light and heavy load lines is in the harsh environment of sun exposure and sea water alternately soaking and scouring. The cuprous oxide antifouling agent in the antifouling paint at this part faces a high risk of oxidation failure. This is mainly because cuprous oxide is easily oxidized by the photogenerated holes (h ⁺ ) generated by itself under visible light irradiation to cause photocorrosion. This hole generation-transfer process is significantly affected by the morphology of the cuprous oxide structure. The conventionally used industrial-grade cuprous oxide antifouling agent is micron-sized particles without regular morphology, and its photogenerated carriers are more likely to be enriched on the surface, resulting in severe photocorrosion and oxidation, which seriously deteriorates the performance of the antifouling paint on the waterline , and to a certain extent lead to the risk of antifouling failure of underwater parts.

In order to solve the failure problem of cuprous oxide antifouling agent on the waterline, it is urgent to improve the stability of cuprous oxide under light environment. The key is to strengthen the separation and transfer of photogenerated carriers on the surface of cuprous oxide through structural regulation. . In this regard, the academic community has reached a certain consensus: the document J.Phys.Chem.C2009, 113, 14448 compared the stability of a series of cuprous oxide single crystal particles with different shapes, and pointed out that the crystal plane is completely composed of (111) Octahedral single crystal has the most excellent photostability, thanks to its (111) crystal face with lower energy level position, which is conducive to the rapid separation of photogenerated holes. Nevertheless, cuprous oxide particles composed of a single crystal face still face the problem of oxidation and corrosion caused by the accumulation of photogenerated holes. Patent CN104591257B discloses a cubic micronano cuprous oxide powder and a preparation method thereof. The obtained cubic cuprous oxide particles are composed of (100) crystal faces, which are prone to photooxidative corrosion as an antifouling agent under visible light irradiation, and cannot effectively solve the problem of failure of the antifouling agent at the ship's waterline. Fundamentally, the efficient separation of photogenerated holes on the surface of cuprous oxide requires the introduction of energy level difference. For this reason, the prior art proposes a binary heterojunction preparation strategy. Literature Nat.Catal.2018, s41929-018-0077-6 uses electrochemical and single-atom deposition methods to deposit gallium oxide and other heterojunction composite layers on the surface of cuprous oxide nanowires; The band structure promotes the separation of carriers on the surface of cuprous oxide, thereby improving the stability of the material in the photoelectrocatalytic process. However, the preparation method of the above-mentioned heterojunction composite materials is cumbersome and costly, and it is difficult to carry out large-scale preparation for the antifouling field. Therefore, the preparation of a cuprous oxide antifouling agent material with intrinsic energy level differences is an effective strategy to solve the problem of antifouling agent failure at the ship's waterline.

At present, the industry mainly supplements and strengthens the effect of cuprous oxide antifouling agents on the waterline of ships by compounding highly toxic biocides and other formula design methods: Invention patents 201210494499.7 and 201710577196.4 both propose to use tributyl fluoride Tin compounded with cuprous oxide, etc. as an antifouling agent system for ship waterline paint. It is worth noting that the organotin substances used were banned globally by the International Maritime Organization in 2008 due to their extremely high bioaccumulation toxicity. To sum up, the existing research failed to fundamentally solve the bottleneck problem of premature failure of cuprous oxide antifouling agents on the waterline of ships due to photocorrosion and oxidation.

Contents of the invention

In view of this, the present invention aims to propose a light-responsive cuprous oxide antifouling agent, which efficiently separates photogenerated holes by virtue of the energy level difference between crystal planes to inhibit the corrosion and oxidation of cuprous oxide, thereby solving the problem of antifouling agents on the waterline of ships. Ineffective bottleneck problem. The cuprous oxide antifouling agent used in the prior art does not have a regular morphology and cannot form an energy level difference between crystal planes. Therefore, the surface is more likely to be enriched with photogenerated holes under visible light irradiation, resulting in severe photocorrosion oxidation that makes the waterline The performance of the antifouling paint is degraded or even invalid.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

A light-responsive cuprous oxide antifouling agent, including cuprous oxide octahedral micro-nanoparticles with special exposed crystal planes, the cuprous oxide micro-nanoparticles are composed of 6 (100) crystal planes and 8 (111 ) crystal plane closed composition, each (111) crystal plane is adjacent to 3 (100) crystal planes, there are 36 edges and 24 vertices in total, the particle size distribution is 500nm～2μm, and the cuprous oxide micro-nano particles pass through Preparation by Surfactant-Mediated Wet Chemical Reduction Strategy.

A preparation method of a photoresponsive cuprous oxide antifouling agent, which is used to prepare the above-mentioned photoresponsive cuprous oxide antifouling agent, comprising the following steps:

1) Dissolve soluble divalent copper salt in 80-4500mL deionized water at a reaction temperature of 50-70°C, then add inorganic base and polyvinylpyrrolidone surfactant, and stir at a constant speed for 0.5-1.5 hours to obtain blue or Blue-green copper hydroxide suspension;

2) Dissolve the reducing agent in 10-800mL deionized water, and add dropwise to the above-prepared copper hydroxide suspension, perform a reduction reaction at a temperature of 50-70°C for 0.5-1 hour, and then use a washing solvent for centrifugal washing , obtained octahedral cuprous oxide micro-nanoparticles with special exposed crystal planes after vacuum drying.

Further, the molar ratio of the divalent copper salt to the inorganic base in step 1) is 1:30-55.

Further, the molar ratio of divalent copper salt to polyvinylpyrrolidone in step 1) is 10-33:1.

Further, the molar ratio of copper hydroxide to reducing agent in step 2 is 1:3-8.

Further, the divalent copper salt is one or a combination of copper sulfate, copper chloride, copper acetate and copper nitrate.

Further, the inorganic base is one or a combination of sodium hydroxide and potassium hydroxide.

Further, the reducing agent is one or a combination of ascorbic acid, glucose, and sodium sulfite.

Further, the washing solvent is one or a combination of methanol, ethanol, and isopropanol.

Further, the vacuum drying temperature is 30-40° C., and the drying time is 12-24 hours.

Compared with the prior art, the photoresponsive cuprous oxide antifouling agent of the present invention and its preparation method have the following advantages:

(1) The present invention proposes a light-responsive cuprous oxide antifouling agent, which is suitable for the waterline position of the ship. Based on the surfactant-mediated wet chemical reduction strategy, a truncated octahedral cuprous oxide with special exposed crystal faces is obtained. copper micronanoparticles. Under sunlight irradiation, the photoresponsive cuprous oxide particles can quickly separate the surface by virtue of the energy level difference between different crystal planes to generate photogenerated carriers (electron-holes, e ^- -h ⁺ ), on the one hand suppress photogenerated holes On the other hand, it catalyzes dissolved oxygen (O ₂ ), water (H ₂ O) and hydroxide ions (OH ^- ) in seawater to generate oxygen anions (·O ^2- ), hydroxyl radicals (HO· ) and other active species to kill marine fouling organisms attached to the waterline, thereby exerting antifouling activity. In addition, cuprous oxide can slow down the release of copper ions due to its small particle size and play a long-term bactericidal role effect.

(2) The photoresponsive cuprous oxide antifouling agent prepared by the present invention is suitable for various antifouling coating systems such as the existing abrasive type, self-polishing type, and fouling release type, and can be applied to ship waterlines Location.

(3) the present invention proposes a kind of preparation method of photoresponsive cuprous oxide antifouling agent, take divalent cupric salt as copper source, take polyvinylpyrrolidone as structure directing agent, after copper salt reacts with strong base, through reduction Cuprous oxide micro-nanoparticles with special exposed crystal facets were prepared by reduction with reagents. The preparation route is clear, the reaction conditions are simple, the stability is good, non-toxic and harmless, green and environmentally friendly, and the reproducibility is high, which is conducive to large-scale production.

Description of drawings

Fig. 1 is the scanning electron microscope picture of the cuprous oxide of conventional industrial grade;

Fig. 2 is the scanning electron micrograph of the photoresponsive cuprous oxide prepared in embodiment 1;

Fig. 3 is the X-ray diffraction spectrogram of the photoresponsive cuprous oxide prepared in embodiment 1;

Fig. 4 is the infrared spectrogram of the photoresponsive cuprous oxide prepared in embodiment 2;

Fig. 5 is the steady-state fluorescence emission spectrum of photoresponsive cuprous oxide and conventional industrial grade cuprous oxide prepared in embodiment 3;

Fig. 6 is the comparison diagram of the antibacterial activity before and after the light-responsive cuprous oxide prepared in Example 1 is added to the active species capture agent;

Fig. 7 is the comparison chart of the antibacterial activity before and after the cuprous oxide of conventional industrial grade is added active species capture agent;

8 is a schematic diagram of the light-responsive antifouling mechanism of the light-responsive cuprous oxide prepared in Example 1.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

Example 1

Weigh 0.25g copper sulfate pentahydrate and 2.75g polyvinylpyrrolidone, stir and dissolve in 80mL deionized water at 55°C, weigh 1.68g sodium hydroxide and add to the reaction solution to obtain blue or blue-green copper hydroxide suspension solution; then, weigh 0.85g of ascorbic acid and dissolve it in 10mL of deionized water, then add it dropwise to the above copper hydroxide suspension, and perform a reduction reaction at 55°C for 0.5 hours; finally, use ethanol to wash the reduced product-centrifuge Separated and dried under vacuum at 30°C for 12 hours, a photoresponsive cuprous oxide antifouling agent with special exposed crystal faces was prepared.

Example 2

Weigh 6.7g copper chloride and 145.0g polyvinylpyrrolidone, stir and dissolve in 4500mL deionized water at 70°C, weigh 75.0g sodium hydroxide and add to the reaction solution to obtain a blue or blue-green copper hydroxide suspension ; Subsequently, weigh 45.0g of glucose and dissolve it in 800mL of deionized water, then add it dropwise to the above-mentioned copper hydroxide suspension, and perform a reduction reaction at 70°C for 1 hour; finally, use isopropanol to wash the reduced product- After centrifugation and drying at 40°C for 24 hours under vacuum, a photoresponsive cuprous oxide antifouling agent with special exposed crystal planes was prepared.

Example 3

Weigh 0.9g copper acetate and 7.5g polyvinylpyrrolidone, stir and dissolve in 500mL deionized water at 60°C, weigh 18.5g potassium hydroxide and add it to the reaction solution to obtain a blue or blue-green copper hydroxide suspension; Subsequently, 26.3 g of ascorbic acid was weighed and dissolved in 50 mL of deionized water, and then added dropwise to the above-mentioned copper hydroxide suspension, and reduced for 40 minutes at 60° C.; finally, the reduced product was washed and centrifuged with methanol, And drying at 35°C for 12 hours under vacuum conditions, a photoresponsive cuprous oxide antifouling agent with special exposed crystal planes was prepared.

In this application, conventional industrial-grade cuprous oxide was purchased from Taixing Smelting.

Performance Testing

Figure 1 and Figure 2 are scanning electron microscope images of conventional industrial-grade cuprous oxide and photoresponsive cuprous oxide prepared in Example 1, respectively. It can be seen from Figure 1 that the particle size of cuprous oxide prepared by conventional industrial grades varies greatly, and a single cuprous oxide particle does not have a regular shape, so it cannot form a special exposed crystal plane and a difference in the energy level of the crystal plane, so it is prone to light Oxidation and corrosion, the antifouling effect on the waterline of the ship is poor. It can be seen from Figure 2 that the average particle size of the cuprous oxide prepared in Example 1 is 0.5-2 μm, with clear edges and corners, regular shape, uniform size, and special crystal surface exposure, that is, the cuprous oxide is octahedral The morphology is composed of 6 (100) crystal planes and 8 (111) crystal planes closed, each (111) crystal plane is adjacent to 3 (100) crystal planes, with a total of 36 edges and 24 vertices. Its morphology and structure are significantly different from the existing conventional industrial grade cuprous oxide.

FIG. 3 is an X-ray diffraction spectrum of the photoresponsive cuprous oxide prepared in Example 1. FIG. It can be seen from Figure 3 that the (111)/(100) crystal plane ratio of the prepared cuprous oxide is significantly improved after X-ray diffraction characterization, showing a special exposed crystal plane.

FIG. 4 is an infrared spectrogram of the photoresponsive cuprous oxide prepared in Example 2. It can be seen from Fig. 4 that the photoresponsive cuprous oxide antifouling agent exhibits a Cu(I)-O stretching vibration peak (628cm ^-1 ).

Fig. 5 is a steady-state fluorescence emission spectrum diagram of photoresponsive cuprous oxide prepared in Example 3 and conventional industrial grade cuprous oxide. It can be seen from FIG. 5 that the photoresponsive cuprous oxide antifouling agent exhibits a better separation effect of photogenerated carriers. Specifically, the steady-state fluorescence emission spectrum is used to characterize the recombination luminescence phenomenon of photogenerated carrier pairs (electron-holes) generated by materials excited by a light source. Compared with the conventional industrial-grade cuprous oxide, the cuprous oxide described in Example 3 exhibits significantly lower fluorescence emission intensity, indicating that photogenerated holes and electrons can be transferred rapidly, and the separation effect is enhanced.

Figure 6 and Figure 7 are the comparison charts of the antibacterial activity of the light-responsive cuprous oxide prepared in Example 1 and the conventional industrial grade cuprous oxide before and after adding the active species capture agent, respectively. It can be seen from Figure 6 that the photoresponsive cuprous oxide antifouling agent rapidly separates and consumes photogenerated holes (h+) under visible light irradiation, and generates hydroxyl radicals (HO·), oxygen anions (·O ^2- ) and other antifouling active species. Specifically, the active species capture test is used to characterize the type and quantity of active species generated after the material is excited by visible light. Sodium oxalate, isopropanol, and p-benzoquinone were used as traps for photogenerated holes (h ⁺ ), hydroxyl radicals (OH·), oxygen anions (·O ^2- ) and other active species, and the above traps Added to bacterial (Escherichia coli E.coil) culture medium containing different types of cuprous oxide materials; by comparing the downward trend of bacterial inhibitory activity, the types of main photoactive species on the surface of cuprous oxide were identified. Compared with the conventional industrial-grade cuprous oxide shown in Figure 7, the bacterial inhibitory activity of the cuprous oxide prepared in Example 1 after adding a hole-scavenging agent decreased to a lesser extent, indicating that the exposure of the special crystal plane formed a crystal plane energy level difference. Helps to quickly separate and transport the photogenerated holes generated on the surface of cuprous oxide; at the same time, the antibacterial activity of the prepared photoresponsive cuprous oxide was significantly decreased after adding hydroxyl radicals and oxygen anion traps, indicating that the exposure of special crystal faces Helps to generate active species such as hydroxyl radicals and oxygen anions on the surface of cuprous oxide.

8 is a schematic diagram of the light-responsive antifouling mechanism of the light-responsive cuprous oxide prepared in Example 1. It can be seen from Figure 8 that under the irradiation of visible light, photogenerated carriers are generated on the surface of cuprous oxide. With the help of the energy level difference between the (111) and (100) crystal planes, on the one hand, the photogenerated holes are efficiently separated and transported. It fundamentally inhibits the photocorrosion of cuprous oxide; on the other hand, it quickly transports photogenerated carriers to the antifouling interface, and catalyzes the generation of oxygen anions (·O ^2- ), hydrogen peroxide (H ₂ O ₂ ), hydroxyl radicals (OH ) and other active species to kill the fouling organisms attached to the waterline of the ship, so as to exert light-responsive antifouling activity for a long time.

In summary, the light-responsive cuprous oxide with special crystal surface exposure involved in the present invention is used as an antifouling agent, the synthesis process is simple, it is suitable for the existing antifouling paint formulation system, and it is suitable for exposure to sunlight and alternating dry and wet environments Antifouling applications at the waterline of ships.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (10)

1. A photoresponse type cuprous oxide antifouling agent comprises cuprous oxide truncated octahedral micro-nano particles with special crystal faces exposed, and is characterized in that the cuprous oxide micro-nano particles are formed by closing 6 (100) crystal faces and 8 (111) crystal faces, each (111) crystal face is adjacent to 3 (100) crystal faces, 36 edges and 24 vertexes are formed in total, the particle size distribution is 0.5-2 mu m, and the cuprous oxide micro-nano particles are prepared through a surfactant mediated wet chemical reduction strategy.

2. A method for preparing a photoresponsive cuprous oxide antifouling agent, which is used for preparing the photoresponsive cuprous oxide antifouling agent according to claim 1, and is characterized by comprising the following steps:

1) Dissolving soluble divalent copper salt in 80-4500 mL deionized water at the reaction temperature of 50-70 ℃, then adding inorganic base and polyvinylpyrrolidone surfactant, and stirring at a constant speed for reaction for 0.5-1.5 hours to obtain blue or blue-green copper hydroxide suspension;

2) Dissolving a reducing agent in 10-800 mL of deionized water, dropwise adding the solution into the copper hydroxide suspension prepared in the step 1), carrying out reduction reaction for 0.5-1 h at the temperature of 50-70 ℃, then carrying out centrifugal washing by using a washing solvent, and carrying out vacuum drying to obtain the cuprous oxide truncated octahedral micro-nano particles with special crystal face exposure.

3. The method according to claim 2, wherein the molar ratio of the divalent copper salt to the inorganic base in step 1) is 1.

4. The method according to claim 2, wherein the molar ratio of the divalent copper salt to the polyvinylpyrrolidone in step 1) is 10 to 33.

5. The method according to claim 2, wherein the molar ratio of the copper hydroxide to the reducing agent in step 2 is 1.

6. The method of claim 2, wherein the cupric salt is one or a combination of copper sulfate, copper chloride, copper acetate and copper nitrate.

7. The preparation method according to claim 2, wherein the inorganic base is one or a combination of sodium hydroxide and potassium hydroxide.

8. The method of claim 2, wherein the reducing agent is one or a combination of ascorbic acid, glucose or sodium sulfite.

9. The method according to claim 2, wherein the washing solvent is one or a combination of methanol, ethanol and isopropanol.

10. The method according to claim 2, wherein the vacuum drying temperature is 30 to 40 ℃ and the drying time is 12 to 24 hours.

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