阅读说明：本技术 一种光热转换多孔结构的制备方法及太阳能蒸发装置 (Preparation method of photo-thermal conversion porous structure and solar evaporation device ) 是由 程道来 聂寒璐 吕凤勇 林思帆 于 2021-10-21 设计创作，主要内容包括：本发明公开了一种光热转换多孔结构的制备方法及太阳能蒸发装置,包括泡沫铜和氧化石墨烯,采用如下步骤：S1：配置NaOH和(NH4)2S2O8碱性混合溶液；S2：将所述泡沫铜依次用丙酮、酒精、蒸馏水、盐酸溶液和所述蒸馏水超声清洗,清洗完后用氮气吹干；S3：将所述泡沫铜浸入所述NaOH和(NH4)2S2O8碱性混合溶液中,然后进行恒温氧化,氧化后的所述泡沫铜用蒸馏水冲洗、干燥,使所述泡沫铜表面形成超亲水纳米CuO结构；S4：将所述氧化石墨烯利用超声分散于蒸馏水中,得到GO溶液；S5：将所述泡沫铜浸入所述GO溶液,使得所述氧化石墨烯沉积在所述泡沫铜表面,然后进行恒温干燥,得到CuO/GO复合光热转换结构。该制备方法简单、高效,不需要复杂设备,成本低廉。(The invention discloses a preparation method of a photothermal conversion porous structure and a solar evaporation device, wherein the preparation method comprises the following steps of: s1: preparing an alkaline mixed solution of NaOH and (NH4)2S2O 8; s2: ultrasonically cleaning the foamy copper by using acetone, alcohol, distilled water, a hydrochloric acid solution and the distilled water in sequence, and blow-drying by using nitrogen after cleaning; s3: soaking the copper foam into the alkaline mixed solution of NaOH and (NH4)2S2O8, then carrying out constant-temperature oxidation, washing the oxidized copper foam with distilled water, and drying to form an ultra-hydrophilic nano CuO structure on the surface of the copper foam; s4: dispersing the graphene oxide in distilled water by utilizing ultrasonic waves to obtain a GO solution; s5: and immersing the foamy copper into the GO solution to enable the graphene oxide to be deposited on the surface of the foamy copper, and then drying at constant temperature to obtain the CuO/GO composite photo-thermal conversion structure. The preparation method is simple and efficient, does not need complex equipment and has low cost.)

1. The preparation method of the photothermal conversion porous structure is characterized by comprising the following steps of:

s1: preparation of NaOH and (NH)₄)₂S₂O₈An alkaline mixed solution;

s2: ultrasonically cleaning the foamy copper by using acetone, alcohol, distilled water, a hydrochloric acid solution and the distilled water in sequence, and blow-drying by using nitrogen after cleaning;

s3: immersing the copper foam in the NaOH and (NH)₄)₂S₂O₈In the alkaline mixed solution, then carrying out constant-temperature oxidation, washing the oxidized copper foam with distilled water, and drying to form a super-hydrophilic nano CuO structure on the surface of the copper foam;

s4: dispersing the graphene oxide in distilled water by utilizing ultrasonic waves to obtain a GO solution;

s5: and immersing the foamy copper into the GO solution to enable the graphene oxide to be deposited on the surface of the foamy copper, and then drying at constant temperature to obtain the CuO/GO composite photo-thermal conversion structure.

2. The method for producing a photothermal conversion porous structure according to claim 1, wherein the NaOH and (NH) in S1₄)₂S₂O₈Alkaline mixed solution of NaOH and (NH)₄)₂S₂O₈The molar ratio of (a) to (b) is 25: 1.

3. The method for producing a photothermal conversion porous structure according to claim 1, wherein the concentration of the hydrochloric acid solution in S2 is 2 wt% to 5 wt%.

4. The method for preparing a photothermal conversion porous structure according to claim 1, wherein the temperature of the isothermal oxidation in S3 is 70 ℃ and the time is 30 min.

5. The method of preparing a photothermal conversion porous structure according to claim 1, wherein the GO solution in S4 has a concentration of 5 mg/mL.

6. The method for preparing a photothermal conversion porous structure according to claim 1, wherein the soaking time of the copper foam in S5 is 5min, the constant temperature drying temperature is 50 ℃, and the time is 1 h.

7. A solar evaporation device comprising the CuO/GO composite photothermal conversion structure produced by the method for producing a photothermal conversion porous structure according to any one of claims 1 to 6, further comprising:

a heat insulating container which stores water and has an open top;

the heat insulation layer is arranged in the heat insulation container and is positioned above the water;

the water conveying layer is arranged in the heat insulation container and is positioned above the heat insulation layer, and two sides of the water conveying layer downwards penetrate through the heat insulation layer to extend into the water for absorbing and conveying the water;

the CuO/GO composite photothermal conversion structure is arranged in the heat insulation container and is positioned above the water conveying layer, and the water conveying layer conveys water to the CuO/GO composite photothermal conversion structure.

8. The solar evaporation device of claim 7, wherein the thermal insulation layer is made of porous plastic foam.

9. The solar evaporation device of claim 7, wherein the water transport layer is made of a high water absorption material.

Technical Field

The invention belongs to the technical field of photo-thermal materials, and particularly relates to a preparation method of a photo-thermal conversion porous structure and a solar evaporation device.

Background

Solar thermal technology is the most direct way of solar energy acquisition and utilization. Solar energy driven water interface evaporation is one of the applications of solar thermal technology, and the solar energy is completely utilized without additional input energy, so that the solar energy driven water interface evaporation solar thermal system has good application prospect.

At present, solar energy driven water interface evaporation mainly depends on a photo-thermal material to absorb solar radiation energy and directly or indirectly transfer heat to fluid, but the loss is large in the processes of solar radiation energy absorption and heat transfer, the cost of a photo-thermal system is increased, and the application and popularization of a solar water evaporation technology are limited. The porous photothermal material with the nano structure can enhance the body absorption of solar radiation energy and improve the photothermal conversion efficiency. In the solar interface evaporation system, the input radiation of the sun selectively heats the evaporation part at the top instead of the whole water body, so that the water body is prevented from being heated, and the evaporation efficiency can be effectively improved. At present, the evaporation of the solar interface is mainly concentrated on various self-floating light absorption materials, but sunlight also has certain degree of reflection when being incident on the interface, and the evaporation efficiency is limited to a certain degree due to the limited evaporation interface area.

The existing photo-thermal material has high cost, complex preparation method and low efficiency, and directly restricts the popularization and application of the solar interface evaporation technology.

Disclosure of Invention

In order to solve the above problems, the present invention aims to provide a method for preparing a photothermal conversion porous structure and a solar evaporation apparatus, wherein the method is simple and efficient, does not require complex equipment, and has low cost.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of a photothermal conversion porous structure comprises the following steps of copper foam and graphene oxide:

s1: preparation of NaOH and (NH)₄)₂S₂O₈An alkaline mixed solution;

s2: ultrasonically cleaning the foamy copper by using acetone, alcohol, distilled water, a hydrochloric acid solution and the distilled water in sequence, and blow-drying by using nitrogen after cleaning;

s3: immersing the copper foam in the NaOH and (NH)₄)₂S₂O₈In the alkaline mixed solution, then carrying out constant-temperature oxidation, washing the oxidized copper foam with distilled water, and drying to form a super-hydrophilic nano CuO structure on the surface of the copper foam;

s4: dispersing the graphene oxide in distilled water by utilizing ultrasonic waves to obtain a GO solution;

s5: and immersing the foamy copper into the GO solution to enable the graphene oxide to be deposited on the surface of the foamy copper, and then drying at constant temperature to obtain the CuO/GO composite photo-thermal conversion structure.

The NaOH and (NH) in S1 according to an embodiment of the present invention₄)₂S₂O₈Alkaline mixed solution of NaOH and (NH)₄)₂S₂O₈The molar ratio of (a) to (b) is 25: 1.

According to an embodiment of the present invention, the concentration of the hydrochloric acid solution in S2 is 2 wt% to 5 wt%.

According to an embodiment of the present invention, the temperature of the constant temperature oxidation in S3 is 70 ℃ and the time is 30 min.

According to an embodiment of the invention, the GO solution concentration in S4 is 5 mg/mL.

According to an embodiment of the invention, the soaking time of the foamy copper in the step S5 is 5min, the constant temperature drying temperature is 50 ℃, and the time is 1 h.

Based on the same concept, the invention also provides a solar evaporation device, which comprises the CuO/GO composite photothermal conversion structure prepared by the preparation method of the photothermal conversion porous structure of any embodiment, and further comprises:

a heat insulating container which stores water and has an open top;

the heat insulation layer is arranged in the heat insulation container and is positioned above the water;

the water conveying layer is arranged in the heat insulation container and is positioned above the heat insulation layer, and two sides of the water conveying layer downwards penetrate through the heat insulation layer to extend into the water for absorbing and conveying the water;

the CuO/GO composite photothermal conversion structure is arranged in the heat insulation container and is positioned above the water conveying layer, and the water conveying layer conveys water to the CuO/GO composite photothermal conversion structure.

According to an embodiment of the present invention, the material of the heat insulating layer is porous plastic foam.

According to an embodiment of the present invention, the water transporting layer is made of a high water absorption material.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects:

(1) in the steps from S1 to S5 in the embodiment of the invention, the super-hydrophilic nano CuO structure is prepared on the surface of the skeleton structure of the foamy copper through chemical reaction, and then GO is deposited to form a CuO/GO composite photo-thermal conversion structure.

(2) In the embodiment of the invention, the CuO/GO composite photo-thermal conversion structure of the solar evaporation device converts incident sunlight from surface absorption to bulk absorption; due to the black CuO and GO, the absorption capacity to sunlight is enhanced; meanwhile, as the nano CuO structure on the copper foam has super-hydrophilicity, the copper foam is easily wetted by water, and the evaporation capacity of the thin liquid film is improved; the evaporation process of water in the foam copper is changed from surface evaporation to bulk evaporation, and the light absorption performance and the evaporation performance are further improved.

(3) In the embodiment of the invention, the heat insulating layer is porous plastic foam with low heat conductivity, so that the heat conduction loss of heat to a water body is reduced. The water conveying layer is made of a material with good water absorption, absorbs water from the bottom water body under the action of capillary force, continuously conveys the water to the CuO/GO composite photo-thermal conversion structure along the periphery of the inner wall of the heat insulation container, and concentrates heat on the evaporation layer due to the fact that the heat conductivity coefficient of the heat insulation layer is very low, so that liquid film evaporation is promoted, and photo-thermal conversion efficiency is further improved.

Drawings

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings, in which:

FIG. 1 is a schematic view of the solar evaporator according to the present invention;

FIG. 2 is a SEM schematic diagram of a super-hydrophilic nano CuO structure according to the present invention;

FIG. 3 shows the super-hydrophilic contact angle (contact angle is) A schematic diagram of (a);

FIG. 4 is a schematic view of the CuO/GO composite photothermal conversion structure of the present invention.

Description of reference numerals:

1: a thermally insulated container; 2: a CuO/GO composite photo-thermal conversion structure; 3: a water conveying layer; 4: a heat insulating layer; 5: and (3) water.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise ratio for the purpose of facilitating and distinctly aiding in the description of the embodiments of the invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

Example 1

The core of the invention is to provide a preparation method of a photothermal conversion porous structure, which comprises the following steps of:

s1: preparation of NaOH and (NH)₄)₂S₂O₈Alkaline mixed solution, NaOH and (NH) are respectively added₄)₂S₂O₈Adding into different beakers, dissolving with distilled water, mixing, and stirring. And the molar concentration ratio of NaOH to (NH4)2S2O8 in the alkaline mixed solution of NaOH and (NH4)2S2O8 is 25: 1.

S2: and ultrasonically cleaning the foamy copper by using acetone, alcohol, distilled water, a hydrochloric acid solution and distilled water in sequence for 5-10 min, and drying the foamy copper by using nitrogen after cleaning, thereby removing organic matters, impurities, oxides, hydroxides and the like on the surface of the foamy copper. Wherein the concentration of the hydrochloric acid solution is 2 wt% -5 wt%.

S3: immersing the copper foam in NaOH and (NH)₄)₂S₂O₈And (3) carrying out constant-temperature oxidation in the alkaline mixed solution, wherein the constant-temperature oxidation temperature is 70 ℃ and the constant-temperature oxidation time is 30 min. And washing the oxidized copper foam with distilled water, and drying to form a super-hydrophilic nano CuO structure on the surface of the copper foam, as shown in figure 2.

S4: and dispersing graphene oxide in distilled water by utilizing ultrasonic waves to obtain a GO solution, wherein the concentration of the GO solution is 5 mg/mL.

S5: and (3) soaking the foamy copper into the GO solution for 5min to enable graphene oxide to be deposited on the surface of the foamy copper, and then drying at a constant temperature, wherein the constant temperature drying temperature is 50 ℃ and the time is 1 h. Finally, a CuO/GO composite photothermal conversion structure is obtained, which is shown in figure 4.

And S1-S5, preparing a super-hydrophilic nano CuO structure on the surface of the skeleton structure of the foamy copper through chemical reaction, and then depositing GO to form a CuO/GO composite photo-thermal conversion structure, wherein the preparation cost is low, the process is simple, and complex equipment is not needed.

Example 2

Another core of the present invention is to provide a solar evaporation apparatus, comprising a CuO/GO composite photothermal conversion structure 2 prepared by the method for preparing a photothermal conversion porous structure of example 1, and further comprising a heat insulating container 1, a heat insulating layer 4, and a water transport layer 3.

The insulated container 1 has water 5 stored in the bottom thereof and is open at the top thereof. Preferably, the insulated container 1 is a low thermal conductivity plastic container.

The heat insulation layer 4 is arranged in the heat insulation container 1 and is positioned above the water 5, and the heat insulation layer 4 is made of porous plastic foam, so that the heat transfer loss from top to bottom can be effectively reduced.

The water delivery layer 3 is disposed in the heat insulation container 1 and above the heat insulation layer 4, two sides of the water delivery layer 3 downwardly penetrate through the heat insulation layer 4 and extend into the water 5 for absorbing and delivering water, the water delivery layer 3 is made of a high water absorption material, and in this embodiment, medical gauze is used. Can effectively absorb and transport water to the CuO/GO composite photo-thermal conversion structure 2.

The CuO/GO composite photothermal conversion structure 2 is arranged in the heat insulation container 1 and is positioned above the water conveying layer 3, and the water conveying layer 3 conveys water to the CuO/GO composite photothermal conversion structure 2 and completely wets the same. The CuO/GO composite photothermal conversion structure 2 absorbs solar energy to evaporate water delivered thereto,

then, sunlight is simulated by using a solar simulator and vertically irradiates the CuO/GO composite photo-thermal conversion structure 2. Obtaining illumination intensity through an irradiator; obtaining mass changes before and after evaporation through a balance; temperature change data was obtained by a T-type thermocouple. The mass is collected every 30min under stable condition, the temperature is collected every 30s, and the test is continued for 180 min. The evaporation efficiency of water and the photothermal conversion efficiency of the invention can be obtained by calculation and analysis of experimental data.

According to the invention, the CuO/GO composite photo-thermal conversion structure 2 is prepared by taking the foamy copper as a framework structure through an oxidation reaction and a physical deposition method. The high absorption of incident light can be realized, the photo-thermal conversion capability is enhanced, water molecules on the structure are rapidly heated, the liquid film evaporation is generated on the heated surface, and the evaporation intensity is improved. Low manufacturing cost, easy popularization and wide application prospect in the aspects of seawater desalination, sewage treatment and the like. The porous framework structure enhances the body absorption of the photo-thermal material to solar radiation, reduces the heat conduction loss from the evaporation structure to a water body, and further improves the solar photo-thermal conversion capacity and the evaporation efficiency.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, it is still within the scope of the present invention if they fall within the scope of the claims of the present invention and their equivalents.