Preparation method of antifouling titanium dioxide

Abstract

The invention relates to the technical field of antifouling preparations, and discloses a preparation method of antifouling titanium dioxide. The method comprises the following steps: carrying out hydrolysis sensitization process treatment on a titanium source, and washing to remove impurities so as to prepare a precursor; calcining the precursor at a preset temperature and carrying out heat preservation; the product obtained after calcination and heat preservation is ground to obtain the antifouling titanium dioxide, the antifouling titanium dioxide is anatase type TiO2 powder of an n-type semiconductor in the crystal form, and the yield of H2O2 generated through the electro-catalysis O2 reduction reaction of the antifouling titanium dioxide is larger than 30%. The anti-fouling titanium dioxide can promote release of the anti-fouling agent at a relatively low cost, and a long-acting and stable anti-fouling effect is obtained.

Description

Technical Field

[0001] The present application relates to the technical field of antifouling preparations, and in particular to a method for preparing antifouling titanium dioxide. Background Art

[0002] The problem of marine microorganisms causing fouling, inefficiency and damage to marine engineering and marine equipment is becoming increasingly prominent, so long-term, efficient and intelligent marine antifouling technology has become a difficult problem that urgently needs to be solved in the development of the marine economy. At present, antifouling coatings have become the simplest and most effective way to inhibit biological fouling on the surface of marine engineering. As an indispensable component of marine antifouling coatings, the performance of antifouling agents directly determines the use effect of antifouling coatings.

[0003] The most common antifouling agents on the market are copper-based antifouling agents, such as Cu2O, Cu, etc. However, studies have shown that in the use of Cu2O-based antifouling coatings, the amount of Cu2O added must reach more than 40% of the coating to achieve a good antifouling effect, and the effective utilization rate is low, which will cause unnecessary waste of copper resources and marine environmental pollution; and Cu as an antifouling agent for antifouling coatings also has certain limitations. On the one hand, its cost is relatively high, and on the other hand, it is not very effective in the initial stage of antifouling. 2+ The release rate is too fast and the release concentration is much higher than the half-lethal concentration of fouling organisms, resulting in improper marine environmental pollution. 2+ The release rate slowed down and the released Cu 2+ The concentration is insufficient to achieve effective antifouling effect, resulting in low effective utilization of Cu.

[0004] Therefore, there is an urgent need for a method for preparing an antifouling preparation with low cost and good antifouling effect. Summary of the invention

[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical elements or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0006] In view of the deficiencies in the prior art, the embodiments of the present disclosure provide a method for preparing an antifouling titanium dioxide, which is capable of obtaining a long-lasting and stable antifouling product at a relatively low cost.

[0007] In a first aspect, an embodiment of the present disclosure provides a method for preparing an anti-fouling titanium dioxide, comprising the following steps: subjecting a titanium source to a hydrolysis sensitization process treatment and washing and removing impurities to prepare a precursor; calcining the precursor at a preset temperature and holding the temperature; grinding the product after calcination and holding to obtain an anti-fouling titanium dioxide, wherein the crystal form of the anti-fouling titanium dioxide is anatase TiO2 powder of an n-type semiconductor, and the yield of electrocatalytic O2 reduction reaction to generate H2O2 of the anti-fouling titanium dioxide > 30%.

[0008] In the technical solution of the above method for preparing an anti-fouling titanium dioxide, an accelerating anti-fouling material is added to the anti-fouling titanium dioxide, and the accelerating anti-fouling material includes one or several of Cu and its alloys, Cu2O, CuO, Zn and its alloys, ZnO, organic copper compounds, organic zinc compounds, plant extracts and their composite resins, microbial metabolites and their composite resins.

[0009] In the technical solution of the above method for preparing an anti-fouling titanium dioxide, subjecting the titanium source to a hydrolysis sensitization process treatment and washing and removing impurities to prepare a precursor includes: taking a certain volume of TiCl3 solution and deionized water and preheating them at a first preset temperature T1 °C respectively, and heating the preheated TiCl3 solution and deionized water to a second preset temperature T2 °C; under stirring conditions, adding the TiCl3 solution dropwise to the deionized water for hydrolysis and replenishing water every first preset time t1 minutes, wherein the hydrolysis time is a second preset time t2 minutes and the hydrolysis temperature is a third preset temperature T3 °C; filtering the hydrolyzed solution by suction and drying it at a fourth preset temperature T4 °C for a third preset time t3 minutes and then grinding it into powder, wherein, 20 minutes < t1 < 40 minutes, 100 minutes < t2 < 150 minutes, 300 minutes < t3 < 480 minutes, T1 < T4 < T2 < T3.

[0010] In the technical solution of the above method for preparing an anti-fouling titanium dioxide, subjecting the titanium source to a hydrolysis sensitization process treatment and washing and removing impurities to prepare a precursor includes: dissolving a certain mass fraction of titanium sulfate in a certain volume of deionized water and adding a certain volume of NaOH solution until completely dissolved to form a mixed solution; filtering the mixed solution by suction and heating the filtered solution for hydrolysis, wherein the hydrolysis time is a fourth preset time t4 minutes and the hydrolysis temperature is a fourth preset temperature T4 °C; filtering the hydrolyzed solution by suction and drying it at a fourth preset temperature T4 °C for a fifth preset time t5 minutes and then grinding it into powder, wherein, 60 minutes < t4 < 120 minutes, 240 minutes < t5 < 360 minutes.

[0011] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the process of hydrolyzing and sensitizing the titanium source and washing and removing impurities to prepare the precursor includes: subjecting industrial titanium liquid to seed sensitization, hydrolysis, first washing, bleaching, and second washing to obtain metatitanic acid; drying the metatitanic acid obtained after the second washing at the fourth preset temperature of T4 °C for the fifth preset time of t5 minutes and grinding it into powder.

[0012] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the process of calcining and holding the precursor at a preset temperature includes: heating a certain mass fraction of powdered precursor to T5 °C at a rate of V1 °C / min for calcination and holding for the sixth preset time of t6 minutes, where 50 minutes < t6 < 200 minutes.

[0013] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the process of grinding the product after calcination and holding to obtain anti-fouling titanium dioxide includes: air-cooling the product after calcination and holding to room temperature, and then grinding it into powder to obtain anti-fouling titanium dioxide.

[0014] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the calcination temperature is 350 °C to 600 °C, and the holding time > 0.5 h.

[0015] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the titanium source includes one or more of industrial titanium liquid, tetrabutyl titanate, titanium ethylate, titanium sulfate, titanium alkoxide, titanate, titanium oxychloride, titanium oxysulfate, titanium trichloride, and titanium tetrachloride.

[0016] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the calcination temperature is 400 °C to 500 °C, and the holding time is 2 h.

[0017] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the grinding device includes one or more of Raymond mill, impact crusher, dry stirring mill, jet mill, vertical mill, ring-roll mill, vibration mill, ball mill, sand mill, and tank mill.

[0018] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the band gap of the anti-fouling titanium dioxide < 4.0 eV, and the conduction band potential is 1.10 to 4.0 eV.

[0019] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the grain size of the anti-fouling titanium dioxide > 5.0 nm.

[0020] In the technical solution of the above preparation method of anti-fouling titanium dioxide, the work function of the anti-fouling titanium dioxide > 4.3 eV.

[0021] The method for preparing the antifouling titanium dioxide provided in the embodiments of the present disclosure can achieve the following technical effects: The antifouling titanium dioxide described in the present invention can accelerate the "corrosion and dissolution" of antifouling materials in water and continuously release antifouling substances or ions when there is no or weak light, which not only reduces the load of antifouling materials in antifouling coatings, but also solves the problem of uncontrollable release of antifouling agents in existing antifouling coatings, thereby achieving all-weather antifouling effect.

[0022] The antifouling titanium dioxide described in the present invention can also accelerate the "corrosion" of the antifouling material in water and continuously release antifouling substances or ions when the seawater is still, thereby achieving a static antifouling effect.

[0023] The antifouling titanium dioxide described in the present invention accelerates the rate at which the antifouling material "corrodes and dissolves" to release antifouling substances or ions, which can be regulated by the corrosion-promoting activity of titanium dioxide or the microstructure of titanium dioxide to meet the requirements of different self-polishing antifouling coating systems for the release of antifouling agents.

[0024] The preparation method of the antifouling titanium dioxide of the present invention is simple, highly repeatable, chemically reactive, simple in process, low in cost, and convenient for large-scale production, so that the composite antifouling agent can be effectively applied to the application field of marine antifouling coatings.

[0025] The antifouling titanium dioxide of the present invention can be used in combination with commercial antifouling materials, and not only has an antifouling effect that is better than that of simple antifouling materials, but also has good compatibility with antifouling coatings, and can replace the latter.

[0026] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein: Figure 1 A schematic flow chart of a method for preparing an antifouling titanium dioxide provided by the present invention is shown; Figure 2 A comparison diagram of the antifouling effect of the antifouling hanging plate in Application Example 1 provided by the present invention before use and after use for four months is shown; Figure 3 A comparison diagram of the antifouling effect of the antifouling hanging plate in Application Example 2 provided by the present invention before use and after use for four months is shown; Figure 4 A comparison diagram of the antifouling effect of the antifouling hanging plate in Comparative Example 1 provided by the present invention before use and after four months of use is shown; Figure 5A comparison diagram of the antifouling effect of the antifouling hanging plate in Comparative Example 2 provided by the present invention before use and after four months of use is shown; Figure 6 A comparison chart of the antifouling effects of the antifouling hanging plate in Comparative Example 3 provided by the present invention before use and after four months of use is shown. DETAILED DESCRIPTION

[0028] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0029] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0030] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0031] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0032] Unless otherwise stated, the term "plurality" means two or more.

[0033] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0034] like Figure 1 As shown, an embodiment of the present disclosure provides a method for preparing an antifouling titanium dioxide, comprising: Step S1: subjecting the titanium source to a hydrolysis sensitization process and washing and removing impurities to prepare a precursor; Step S2: calcining the precursor at a preset temperature and keeping the temperature; Step S3: Grind the calcined and heat-insulated product to obtain anti-fouling titanium dioxide, wherein the crystal form of the anti-fouling titanium dioxide is anatase-type TiO2 powder of an n-type semiconductor, and the yield of H2O2 generated by the electrocatalytic O2 reduction reaction of the anti-fouling titanium dioxide is greater than 30%.

[0035] Specifically, the preparation method of the antifouling titanium dioxide of the present invention uses a titanium source treated by a hydrolysis sensitization process as a precursor. Among them, the titanium source includes but is not limited to one or more of industrial titanium liquid, tetrabutyl titanate, ethyl titanate, titanium sulfate, titanium alkoxide, titanate, titanium dichloride, titanium sulfate, titanium trichloride, and titanium tetrachloride. Preferably, after the titanium source is washed and impurities are removed, it is calcined at a preset temperature, and the calcination temperature can ensure that the preparation of the precursor can be fully executed. The insulation time can ensure that the performance of the precursor is excellent. When grinding, the grinding device includes but is not limited to one of Raymond mill, impact mill, dry stirring mill, air flow mill, vertical mill, ring roller mill, vibration mill, ball mill, sand mill, and pot mill. Ball milling is preferably used. The crystal form of the antifouling titanium dioxide is anatase TiO2 powder of an n-type semiconductor, with a band gap of <4.0 eV, a conduction band potential of 1.10~4.0 eV, a grain size of >5.0 nm, and a work function of >4.3 eV. The yield of H2O2 generated by electrocatalytic O2 reduction reaction is greater than 30%. The antifouling titanium dioxide can accelerate the "corrosion" of antifouling materials to release antifouling agents in an environment without light or with weak light, and has the advantages of high efficiency, simple preparation process, and suitability for large-scale production.

[0036] Preferably, the work function of the antifouling titanium dioxide is greater than 4.63 eV.

[0037] In the preferred technical solution of the present application, an accelerating antifouling material is added to the antifouling titanium dioxide, and the accelerating antifouling material includes one or more of Cu and its alloys, Cu2O, CuO, Zn and its alloys, ZnO, organic copper compounds, organic zinc compounds, plant extracts and their composite resins, microbial metabolites and their composite resins.

[0038] Specifically, the addition of an accelerating antifouling material helps to enhance the rate of "corrosion and dissolution" of the antifouling material to release antifouling substances or ions, which can be regulated by the corrosion-promoting activity of titanium dioxide or the microstructure of titanium dioxide to meet the requirements of different self-polishing antifouling coating systems for the release of antifouling agents.

[0039] In a preferred technical solution of the present application, the process of hydrolyzing and sensitizing the titanium source and washing and removing impurities to prepare the precursor includes: taking a certain volume of TiCl3 solution and deionized water and preheating them at the first preset temperature T1 °C respectively, and heating the preheated TiCl3 solution and deionized water to the second preset temperature T2 °C; under stirring conditions, adding the TiCl3 solution dropwise into the deionized water for hydrolysis and replenishing water every first preset time t1 minutes, where the hydrolysis time is the second preset time t2 minutes and the hydrolysis temperature is the third preset temperature T3 °C; filtering the hydrolyzed solution by suction and drying it at the fourth preset temperature T4 °C for the third preset time t3 minutes and then grinding it into powder, where 20 minutes < t1 < 40 minutes, 100 minutes < t2 < 150 minutes, 300 minutes < t3 < 480 minutes, and T1 < T4 < T2 < T3.

[0040] Specifically, the TiCl3 solution can also be replaced by other solutions as long as there is sufficient Ti3+. Set a constant stirring speed and add the TiCl3 solution dropwise into the deionized water. Due to the evaporation of water caused by heating, water needs to be replenished every once in a while, and the interval time, the first preset time t1 minutes, should meet the requirements of water replenishment. Similarly, the preheating temperature is the first preset temperature T1 °C, the heating temperature is the second preset temperature T2 °C, the hydrolysis temperature is the third preset temperature T3 °C, the hydrolysis time is the second preset time t2 minutes, the drying temperature is the fourth preset temperature T4 °C, and the drying time is the third preset time t3, all of which need to meet their respective requirements. For example, the first preset time t1 is taken as 30 minutes, the second preset time t2 is taken as 120 minutes, the third preset time t3 is taken as 360 minutes, the first preset temperature T1 is taken as 70 °C, the second preset temperature T2 is taken as 100 °C, the third preset temperature T3 is taken as 130 °C, and the fourth preset temperature T4 is taken as 80 °C.

[0041] In a preferred technical solution of the present application, the hydrolysis sensitization process treatment of the titanium source and washing for impurity removal to prepare the precursor includes: dissolving a certain mass portion of titanium sulfate in a certain volume of deionized water and simultaneously adding a certain volume of NaOH solution until completely dissolved to form a mixed solution; performing suction filtration on the mixed solution and heating and hydrolyzing the solution after suction filtration, where the hydrolysis time is the fourth preset time t4 minutes and the hydrolysis temperature is the fourth preset temperature T4 °C; performing suction filtration on the hydrolyzed solution and drying it at the fourth preset temperature T4 °C for the fifth preset time t5 minutes and then grinding it into powder, where 60 minutes < t4 < 120 minutes and 240 minutes < t5 < 360 minutes.

[0042] Specifically, for another preparation method of the titanium source, mix titanium sulfate, deionized water, and NaOH solution, and mix the three evenly by stirring to make the solution clear. The hydrolysis time is the fourth preset time t4, the hydrolysis temperature is the fourth preset temperature T4 °C, the drying temperature is the fourth preset temperature T4 °C, and the drying time is the fifth preset time t5, each meeting the requirements. For example, the fourth preset time t4 of the hydrolysis time is taken as 80 minutes, the fifth preset time t5 of the drying time is taken as 300 minutes, and the fourth preset temperature T4 of the hydrolysis temperature and the fourth preset temperature T4 of the drying temperature are both 80 °C.

[0043] In a preferred technical solution of the present application, the hydrolysis sensitization process treatment of the titanium source and washing for impurity removal to prepare the precursor includes: subjecting industrial titanium solution to seed sensitization, hydrolysis, first washing, bleaching, and second washing to obtain metatitanic acid; drying the metatitanic acid obtained after the second washing at the fourth preset temperature T4 °C for the fifth preset time t5 minutes and then grinding it into powder.

[0044] Specifically, for yet another preparation method of the titanium source, take a certain amount of industrial titanium solution to ensure that the Ti 3+ content meets the requirements. The fourth preset temperature T4 of the drying temperature and the fifth preset time t5 of the drying time meet their respective requirements. For example, the fourth preset temperature T4 is taken as 80 °C and the fifth preset time t5 is taken as 300 minutes.

[0045] In a preferred technical solution of the present application, calcining the precursor at a preset temperature and holding the temperature includes: heating a certain mass portion of the powdery precursor to the fifth preset temperature T5 °C at a rate of V1 °C / min for calcination and holding the temperature for the sixth preset time t6 minutes, where 50 minutes < t6 < 200 minutes. The calcination temperature is 350 °C to 600 °C, and the holding time > 0.5 h.

[0046] Specifically, to ensure the calcination effect, the heating rate should not be too fast, so V1 should not be too large. For example, V1 can be 25 °C / min, or 30 °C / min, or 35 °C / min. The holding time is preferably more than half an hour. For example, the sixth preset time t6 is 60 minutes, 120 minutes, or 180 minutes. When the temperature rises to a certain temperature, it can be stopped. The fifth preset temperature T5 is preferably 350 °C to 600 °C.

[0047] Preferably, the calcination temperature is 400 °C to 500 °C and the holding time is 2 h.

[0048] In the preferred technical solution of the present application, the product after calcination and holding is ground to obtain the antifouling titanium dioxide, including: air-cooling the product after calcination and holding to room temperature, and then grinding it into powder to obtain the antifouling titanium dioxide.

[0049] Specifically, the particles of the product after calcination and holding are uneven. To ensure better decontamination effect, it needs to be ground. Before grinding, the product is first cooled to room temperature and then ground into powder to achieve the best antifouling effect.

[0050] For the above-mentioned antifouling titanium dioxide, it has the advantages of controllable performance, high efficiency, simple preparation process, suitable for large-scale production, etc., and can be applied to marine antifouling coatings to improve the performance of marine antifouling coatings.

[0051] Another embodiment of the present disclosure provides a method for preparing a coating, including the following steps: Weigh a certain mass fraction of epoxy varnish, curing agent, antifouling titanium dioxide prepared by the aforementioned preparation method, Cu powder, leveling agent, defoaming agent, and dispersant. Among them, the solid content in the epoxy varnish and the curing agent is 50%; Mix the antifouling titanium dioxide and Cu powder evenly, and add epoxy varnish and stir to obtain the first solvent; Add the anti-settling agent, leveling agent, defoaming agent, and dispersant to the first solvent respectively, stir, and then add the curing agent after stirring evenly and stir again to form the coating.

[0052] Another embodiment of the present disclosure provides a method for preparing an antifouling hanging board. The coating is evenly coated on the epoxy board and left standing at room temperature for the seventh preset time t7 minutes. After the moisture in the coating is evaporated, it is placed at the fourth preset temperature T4 °C and dried for the seventh preset time t7 minutes to obtain the antifouling hanging board, where 600 minutes < t7 < 800 minutes.

[0053] Specifically, an antifouling coating is first prepared, and then applied to an epoxy board to form an antifouling hanging board. When preparing the antifouling coating, a certain mass fraction of the above formula raw materials is weighed. For example, 5g of epoxy varnish, 2g of curing agent, 1.0g of antifouling titanium dioxide, 4.g of Cu powder, and 0.02 g of each auxiliary agent such as anti-settling agent, leveling agent, defoaming agent, dispersant, etc. The mixing process has its corresponding sequence, and the mixing order is antifouling titanium dioxide, Cu powder, epoxy varnish, anti-settling agent, leveling agent, defoaming agent, dispersant and curing agent. After the antifouling coating is applied to the epoxy board, the standing time is relatively long, for example, the seventh preset time t7 is 720 minutes. The prepared antifouling hanging board is based on the antifouling titanium dioxide, which can accelerate the "corrosion and dissolution" of the antifouling material in water when there is no or weak light, and continuously release antifouling substances or ions to achieve all-weather antifouling effect. When the seawater is still, the antifouling titanium dioxide can also accelerate the "corrosion" of the antifouling material in the water, continuously release antifouling substances or ions, and achieve a static antifouling effect. The preparation method of the antifouling titanium dioxide is simple, highly repeatable, and chemically reactive, which is conducive to scale-up production, so that the composite antifouling agent can be effectively used in the field of marine antifouling coatings. The antifouling titanium dioxide has good compatibility with antifouling coatings and is suitable for promotion.

[0054] The embodiments of the present disclosure are further described below with reference to specific embodiments.

[0055] Example 1 First, 100 mL of TiCl3 and 100 mL of deionized water were respectively placed in a 250 mL beaker, and TiCl3 and bottom water were preheated to 70 ℃ in a water bath. Then, the three-necked flask was fixed in an oil bath pot with a universal clamp. When the oil bath pot was raised to 100 ℃, the bottom water was poured into the three-necked flask. Under stirring, the preheated TiCl3 was added dropwise to the three-necked flask through a rubber dropper for hydrolysis. The feeding time should be controlled within 15 min. Then, the timing was started after the solution became turbid. The hydrolysis time was set to 2 h, the hydrolysis temperature was set to 130 ℃, and the evaporated water was replenished in the system every 30 min. The filter was filtered with a 0.450 μm microporous filter membrane, and the filter cake was repeatedly washed with distilled water. After being drum-dried at 80 ℃ for 6 h, it was ground into powder with a mortar. 10 g of the obtained powder was placed in a muffle furnace, and the heating rate was 25 ℃ / min. The calcination temperature was 500 ℃, keep warm for 3 h; finally, after air cooling to room temperature, grind it into powder with a mortar to obtain the antifouling titanium dioxide.

[0056] Example 2 First, 100 g of titanium sulfate was dissolved in 300 mL of deionized water, and 100 mL of NaOH with a concentration of 20 g / L was added, and the mixture was stirred until the mixture was clear; then, the mixture was filtered through a suction filtration device (low-speed filter paper + Buchner funnel), the filtrate was placed in a three-necked flask, and the flask was heated in a water bath, the hydrolysis time was selected to be 80 min and the hydrolysis temperature was 80 °C, and the stirring rate was controlled to be constant at 600 rpm; then, the hydrolyzed solution was filtered again to obtain the final product, and it was dried in an oven at 80 °C for 5 h and ground into powder with a mortar; 20 g of the obtained powder was placed in a muffle furnace, the heating rate was 35 °C / min, the calcination temperature was 450 °C, and the temperature was kept for 4 h; finally, after air cooling to room temperature, it was ground into powder with a mortar to obtain the antifouling titanium dioxide.

[0057] Example 3 First, industrial titanium liquid (Ti 3+ content 1 g / L, TiO2 content of about 195 g / L, Fe / TiO2 of about 0.30, F value of about 1.95) is subjected to seed sensitization (1.0%), hydrolysis, first washing, bleaching, and second washing to obtain titanic acid; then, the titanic acid obtained by the second washing process is dried in an oven at 80°C for 5 h, and ground into powder with a mortar; 200 g of the obtained powder is placed in a muffle furnace, the heating rate is 30°C / min, the calcination temperature is 500°C, and the heat is maintained for 2 h; finally, after air cooling to room temperature, it is ground into powder with a vibration mill for 1 h to obtain the anti-fouling titanium dioxide.

[0058] Example 4 First, industrial titanium liquid (Ti 3+ content 1 g / L, TiO2 content 195 g / L, Fe / TiO2 about 0.30, F value about 1.95) is subjected to seed sensitization (2.0%), hydrolysis, first washing, bleaching and second washing to obtain titanic acid; then, the titanic acid obtained by the second washing process is dried in an oven at 80°C for 5 h, and ground into powder with a mortar; 200 g of the obtained powder is placed in a muffle furnace, the heating rate is 30°C / min, the calcination temperature is 450°C, and the heat is kept for 2 h; finally, after air cooling to room temperature, it is ground into powder with a vibration mill for 1 h to obtain the anti-fouling titanium dioxide.

[0059] Example 5 First, industrial titanium liquid (Ti 3+content 3 g / L, TiO2 content 195 g / L, Fe / TiO2 about 0.30, F value about 1.95) is subjected to seed sensitization (3.0%), hydrolysis, and one washing to obtain titanic acid; then, the titanic acid obtained by the one washing process is dried in an oven at 80 ℃ for 5 h, and ground into powder with a mortar; 200 g of the obtained powder is placed in a muffle furnace, the heating rate is 30 ℃ / min, the calcination temperature is 400 ℃, and the heat preservation is carried out for 2 h; finally, after air cooling to room temperature, it is ground into powder with a vibration mill for 1 h to obtain the anti-fouling titanium dioxide.

[0060] Application Example 1 Coating formula: 8.0 g commercial epoxy varnish (solid content 50%), 2.0 g curing agent (solid content 50%), 1.0 g antifouling titanium dioxide prepared in Example 4, 4.0 g Cu powder; 0.02 g each of anti-settling agent, leveling agent, defoaming agent, dispersant and other additives; Coating preparation process: Prepare coating according to the above ratio, weigh 1.0 g of antifouling titanium dioxide prepared in Example 4 and 4.0 g of Cu powder and mix them evenly, add 8.0 g of epoxy varnish and stir them thoroughly, then add 0.02 g of anti-settling agent, leveling agent, defoamer and dispersant respectively and stir again, and finally add 2.0 g of curing agent. After the coating is fully stirred, evenly apply it on the epoxy board, leave it at room temperature for 12 hours, wait for the solvent to evaporate and dry, put it in an oven at 80 ° C for 12 hours to obtain a hanging piece, and its antifouling effect is as follows: Figure 2 shown.

[0061] Application Example 2 Coating formula: commercial epoxy varnish 8.0 g (solid content 50%), curing agent 2.0 g (solid content 50%), antifouling titanium dioxide prepared in Example 5 1.0 g, Cu powder 4.0 g; anti-settling agent, leveling agent, defoaming agent, dispersant and other additives 0.02 g each; Coating preparation process: Prepare coating according to the above ratio, weigh 1.0 g of antifouling titanium dioxide and 4.0 g of Cu powder prepared in Example 5, add 8.0 g of epoxy varnish and stir well, then add 0.02 g of anti-settling agent, leveling agent, defoamer and dispersant respectively and stir again, finally add 2.0 g of curing agent. After stirring the coating well, evenly apply it on the epoxy board, place it at room temperature for 12 hours, wait for the solvent to evaporate and dry, put it in an oven at 80 ° C for 12 hours to obtain a hanging piece, and its antifouling effect is as follows: Figure 3 shown.

[0062] Comparative Example 1 Coating formula: commercial epoxy varnish 8.0 g (solid content 50%), curing agent 2.0 g (solid content 50%); anti-settling agent, leveling agent, defoaming agent, dispersant and other additives 0.02 g each; Coating preparation process: Prepare coating according to the above ratio, weigh 8.0 g of epoxy varnish and stir thoroughly, then add 0.02 g of anti-settling agent, leveling agent, defoamer, and dispersant respectively and stir again, and finally add 2.0 g of curing agent. After the coating is fully stirred, evenly apply it on the epoxy board, leave it at room temperature for 12 hours, wait for the solvent to evaporate, and then put it in an 80 ℃ oven to dry for 12 hours to obtain a hanging piece. Its antifouling effect is as follows: Figure 4 shown.

[0063] Comparative Example 2 Material formula: 8.0 g commercial epoxy varnish (50% solid content), 2.0 g curing agent (50% solid content), 5.0 g commercial antifouling Cu2O; 0.02 g each of anti-settling agent, leveling agent, defoaming agent, dispersant and other additives; Coating preparation process: Prepare coating according to the above ratio, weigh 5.0 g of commercial Cu2O antifouling agent, add 8.0 g of epoxy varnish to it and stir thoroughly, then add 0.02 g of anti-settling agent, leveling agent, defoamer, and dispersant respectively and stir again, and finally add 2.0 g of curing agent. After the coating is fully stirred, evenly apply it on the epoxy board, leave it at room temperature for 12 hours, and after the solvent evaporates, put it in an 80 ℃ oven and dry it for 12 hours to obtain a hanging piece, such as Figure 5 shown.

[0064] Comparative Example 3 Coating formula: 8.0 g commercial epoxy varnish (50% solid content), 2.0 g curing agent (50% solid content), 1.0 g commercial anatase TiO2, 4.0 g Cu powder; 0.02 g each of anti-settling agent, leveling agent, defoaming agent, dispersant and other additives; Coating preparation process: Prepare coating according to the above ratio, weigh 1.0 g of commercial anatase TiO2 and 4.0 g of Cu powder, add 8.0 g of epoxy varnish and stir thoroughly, then add 0.02 g of anti-settling agent, leveling agent, defoamer and dispersant respectively and stir again, finally add 2.0 g of curing agent. After the coating is fully stirred, evenly apply it on the epoxy board, leave it at room temperature for 12 hours, wait for the solvent to evaporate and dry, put it in an oven at 80 ℃ and dry it for 12 hours to obtain a hanging piece, and its antifouling effect is as follows: Figure 6 shown.

[0065] Through the above examples and comparative examples, it can be seen that the antifouling titanium dioxide and its preparation method proposed in the present application, the antifouling TiO2 is the filler of the antifouling coating, which can promote the "corrosion and dissolution" of antifouling materials (such as Cu, Cu2O, etc.) to release antifouling agents (such as Cu + , Cu 2+), which not only reduces the amount of antifouling materials in antifouling coatings, but also solves the problem of uncontrollable release and low efficiency of antifouling agents in existing antifouling coatings, thereby meeting the low-cost, long-term and stable application requirements of antifouling coatings. The preparation process of antifouling titanium dioxide is simple, low-cost, and easy to mass produce, which is suitable for promotion and application in the field of marine antifouling coating technology.

[0066] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for preparing an antifouling titanium dioxide, characterized in that: It includes the following steps: Subject the titanium source to a hydrolysis sensitization process treatment and wash and remove impurities to prepare a precursor; Calcine the precursor at a preset temperature and keep it warm; Grind the product after calcination and heat preservation to obtain anti-fouling titanium dioxide. The crystal form of the anti-fouling titanium dioxide is anatase TiO2 powder of n-type semiconductor, and the yield of electrocatalytic O2 reduction reaction to generate H2O2 of the anti-fouling titanium dioxide > 30%.

2. The preparation method according to claim 1, characterized in that: It also includes: Add an accelerating anti-fouling material to the anti-fouling titanium dioxide. The accelerating anti-fouling material includes one or several of Cu and its alloys, Cu2O, CuO, Zn and its alloys, ZnO, organic copper compounds, organic zinc compounds, plant extracts and their composite resins, microbial metabolites and their composite resins.

3. The preparation method according to claim 1, characterized in that: The step of subjecting the titanium source to a hydrolysis sensitization process treatment and washing and removing impurities to prepare a precursor includes: Take a certain volume of titanium source and deionized water, preheat them at the first preset temperature T1 °C respectively, and heat the preheated TiCl3 solution and deionized water to the second preset temperature T2 °C; Under the condition of stirring, dropwise add the titanium source into the deionized water for hydrolysis, and supplement water every first preset time t1 minutes. The hydrolysis time is the second preset time t2 minutes, and the hydrolysis temperature is the third preset temperature T3 °C; Filter the hydrolyzed solution by suction, dry it at the fourth preset temperature T4 °C for the third preset time t3 minutes, and then grind it into powder. Among them, 20 minutes < t1 < 40 minutes, 100 minutes < t2 < 150 minutes, 300 minutes < t3 < 480 minutes, T1 < T4 < T2 < T3.

4. The preparation method according to claim 1, characterized in that: The step of subjecting the titanium source to a hydrolysis sensitization process treatment and washing and removing impurities to prepare a precursor includes: Disperse a certain mass fraction of the hydrolyzed titanium source in a certain volume of deionized water, and add a certain volume of NaOH solution until it is completely dissolved to form a mixed solution; Filter the mixed solution by suction and heat-hydrolyze the filtered solution. The hydrolysis time is the fourth preset time t4 minutes, and the hydrolysis temperature is the fourth preset temperature T4 °C; Filter the hydrolyzed solution by suction, dry it at the fourth preset temperature T4 °C for the fifth preset time t5 minutes, and then grind it into powder. Among them, 60 minutes < t4 < 120 minutes, 240 minutes < t5 < 360 minutes.

5. The preparation method according to claim 1, characterized in that: The step of subjecting the titanium source to a hydrolysis sensitization process treatment and washing and removing impurities to prepare a precursor includes: Subject the industrial titanium liquid to seed sensitization, hydrolysis, first washing, bleaching, and second washing to obtain metatitanic acid; Dry the metatitanic acid obtained after the second washing at the fourth preset temperature T4 °C for the fifth preset time t5 minutes and grind it into powder.

6. The preparation method according to any one of claims 1 to 5, characterized in that The step of calcining the precursor at a preset temperature and keeping it warm includes: Heat a certain mass fraction of the powdery precursor to the fifth preset temperature T5 °C at a rate of V1 °C / min for calcination, and keep it warm for the sixth preset time t6 minutes, where 50 minutes < t6 < 200 minutes.

7. The preparation method according to claim 1, characterized in that The calcination temperature is 350 °C to 600 °C, and the heat preservation time > 0.5 h.

8. The preparation method according to claim 1, characterized in that: The step of grinding the product after calcination and heat preservation to obtain anti-fouling titanium dioxide includes: The calcined and heat-insulated product is air-cooled to room temperature and then ground into powder to obtain antifouling titanium dioxide.

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