Recently, the team of Professor Zhang Qianqian of Beijing University of Technology chose natural clay raw materials to prepare a all -natural two -dimensional fluid film with a maximum area of 700cm2.

Picture | Zhang Qianqian (Source: Zhang Qianqian)

Under the conditions of simulated seawater and river water, the infiltration energy of the all-natural two-dimensional fluid membrane reaches 8.61WM-2Essence

Compared with the previous similar achievements of the research team, it has increased by 1.7 times, and it is a leading level in the field of two -dimensional membrane salt.At the same time, it has also achieved a long 30 -day stable continuous long cycle salt difference.

Compared to the mainstream two -dimensional membrane,The resource consumption of layer -shaped clay membranes built this time has dropped to 1/14, greenhouse gas emissions drop to 1/9, and production costs will be reduced to 1/13, showing important economic, resource and environmental benefitsEssence

(Source: Nature Communications)

This not only provides power generation for large -scale salt difference, but also provides reliable membrane foundation and new strategies.It also provides new ideas for developing two -dimensional membrane materials for large -scale preparation, which is expected to promote the development and application of membrane new energy technology.

Specifically:

First of all, this result can be used for “zero carbon” salt difference.

Natural seawater/river water, industrial waste salt and water, etc. there is a huge reserves of ionic salt poor electrochemical potential, so this result can be used for efficient capture. By building a salt -poor battery moduleCapture and utilization.

Secondly,This result is also universal in battery systems such as lithium batteries and liquid stream batteries, that is, it can be used as a functional diaphragm to optimize ions transmission, thereby improving the energy density of battery and battery life.

Third, the ion selection of the ion selection of this achievement has also shown important application potential in the field of environmental resources and water resources. Specific applications include sewage treatment, salt lake lithium, saline refinement, and seawater desalination.

(Source: Nature Communications)

Ionic selectivity and ionic “fish and bear’s paw”

As we all know, there are clean energy sources in nature in nature, such as solar energy and wind energy.How to collect and use these low -density energy efficiently is a huge challenge.

The ocean accounts for 71%of the surface of the earth. It not only provides rich aquatic products and minerals for humans, but also contains huge energy.

The salt poor energy is a clean “zero carbon” energy with a wide range of reserves and strong environmental stability.

The salt difference can obtain electrical energy based on the chemical potential difference between different salinous seawater/river water. The entire power generation process does not have pollutants and carbon dioxide emissions, and does not rely on seasonal and weather conditions. It has the advantages of clean environmental protection and continuous continuous power generation in all -weather.

Theoretically, the total amount of global rivers and sea salt can reach 2.6 TW, which is equivalent to 17%of global electricity consumption.However, how to use salt difference efficiently is a challenging topic.

At present, the anti -electrodiaovers (RED, Reverse Electrodialysis) technology with ionic membranes as the core is considered to be the most industrialized salt difference to power generation technology. Its core component is the ion selection through the membrane.

This type of ions choose to pass through the membrane and require a single charge ion for selective transmission.

Only in this way can two different concentrations of salt solution be separated, so that the salt -driven single charge ion moves directional movement, and then the chemical potential difference is generated on both sides of the membrane.In this way, chemical potential energy is directly converted into electrical energy.

In order to obtain efficient salt difference, the ideal ion selection film should also have high ions selectivity and high ions through.

However, there are usually competitive relationships between “fish” and “bear’s paw”, which brings great challenges to the choice of high -performance ions to choose through the construction of the membrane.

With the development of nano -science and membrane science, the nanomang technology that has emerged in recent years has provided a new platform for high -performance ions to choose through the design of the membrane.

As a nano -pore film, the abacuscular membrane usually has a charge on the surface.The strong static electrostatic effect in the domain -limited channel enables the ions with the opposite charges to selectively pass.

And compared with the body phase transmission, the ion transmission conductivity is usually a few magnitude higher.

Therefore, based on the abatement membrane, it is expected to obtain ionic selectivity and the best balance between ionic through nature to achieve high -efficiency energy conversion of salt difference and power generation.

Classified according to the structure, the abortion film mainly includes: one -dimensional pore -shaped, two -dimensional layers, and three -dimensional network structures.

In recent years, a two -dimensional fluid film with a layered structure can show huge potential in the conversion of salt.The salt difference of a variety of two-dimensional fluid membrane can output the power experimental value, which has reached the level of industrial application (5WM-2To.

In addition, it also has the characteristics of simple preparation and easy functional and modified, and has important prospects in large -scale preparation and salt poor applications.

As a self -supporting film, the two -dimensional fluid film is assembled based on the stacking of two -dimensional nano -chip with electricity. Therefore, two -dimensional materials are its structural subject.

From the perspective of commercialization and environmental protection, the use of natural raw materials to build a two -dimensional fluid film is one of the good choices for the collection and utilization of large -scale penetration energy.

As an important carrier of two -dimensional materials, natural clay ore has the advantages of easy peeling, rich reserves, environment -friendly, low price, etc. It is a good choice to build a two -dimensional fluid film.

However, the surface charges of natural clay mines are limited, and the mechanical strength is very low. Therefore, the mutology film made of natural clay mines is still difficult to output long -term considerable salt and electricity.

Based on this, Zhang Qianqian and the team explored the structural performance optimization and large -scale preparation technology of layer -like clay membranes.

With the help of natural plug -in agents,They realized the stable construction of the clay sheet matrix and completed the large -scale preparation of the all -natural clay base two -dimensional fluid membrane.

(Source: Nature Communications)

Take it naturally, the industry used industry

It is understood that the study began in 2020. At that time, the team chose natural layered clay as raw materials to build a yang ion choice film. The salt difference can be output [1].

Although preliminary verification of clay can be used for salt difference, its energy output is far from meeting actual application requirements (industrialized standards 5WM-2To.

In addition, the mechanical strength of the clay membrane is insufficient, resulting in the long -term power generation stability.

In response to the above problems, the research team used the aramal nano-fiber plug-in clay sheet to build a shell “brick-mud structure”.

Through this, the mechanical strength of the clay membrane and the density of the tunnel charges are effectively improved.) The substantive improvement of the long cycle has also been improved.

Based on the above research, the team continued to carry out preparation of sap membrane.

However, the aramids they used to use before are a kind of artificial fiber. To peel into nano fibers, a large number of organic solvents need to be used, so they do not have economic and environmental benefits.

In addition, the dispersion of the aramid water solution is not conducive to the preparation of the scale of high -performance membranes.Based on this, the research team hopes to seek a nano -fiber alternative with good environmental friendly, well -decentralized aquatic solution, and low cost.

By investigating, they found cellulose nanofiber, which is a natural nano -fiber extracted from plant cellulose, with environmental friendship and cost advantage ($ 20/kg), and is suitable for industrialized production.

After determining the fiber type, they continued to prefer process parameters such as fiber diameter, front -drive liquid concentration, clay tape assembly ratio.

After completing the clay and cellulose nano fiber, the project group successfully constructed this kind of all -natural two -dimensional fluid film.

In this regard, Zhang Qianqian said it was because:

On the one hand, the spatial interoperability formed by the formation of flexible nano fibers and rigid nano -bridge can effectively improve the stability of the two -dimensional fluid membrane. It is the basis for building a large area and high -strength (149MPa) film that builds high ions.

On the other hand, the abundant negative group of cellulose can significantly improve the space negative charge density of the sedentary nano -channel, and promote the rapid selectivity of the cations in the two -dimensional fluid membrane.

Subsequently, the team continued to explore the amplification of the average, stable all -natural mucous membrane.

However, when the membrane is enlarged, a series of problems follow, such as manufacturing equipment upgrades, optimization of film -building liquid, optimized membrane bases, and process parameters adjustment.

After one year of equipment improvement and preparation process optimization, they finally created a large-scale all-natural layer-like mucous membrane with a large area, and achieved high-efficiency salt poor power generation (> 8WM-2) The stability of the long -term power generation (> 30 days) laid the foundation for the collection and use of large -scale penetration energy.

At this point, the team has finally realized the large -scale preparation of high -performance omnidirectional clay membranes and the application of salt poor power generation.

And how to evaluate resources and environmentally friendly natural raw materials, for the green and sustainable development of full -chain from membrane manufacturing and energy collection, it has become a key issue to consider next.

Based on the research characteristics of the material life cycle evaluation of the material life cycle evaluation of the Beijing Institute of Technology, which is located, they believe that they must trace the front end of different materials to synthesize the front end of different materials, and conduct a life cycle evaluation and technical and economic analysis of the entire manufacturing process of the membrane.

Subsequently, the team carried out several months of investigation and visits, thereby obtaining accurate materials production related data, carried out the system’s life cycle evaluation work, and confirmed the advanced nature of the results.

(Source: Nature Communications)

Zhang Qianqian said: “The achievement of these achievements is the result of the joint efforts of teachers and students. The main complete person in this study is my doctoral student Tang Jiadong. He is also the first master’s graduate student after I came to Beigong University.Continue to read the blog, currently a second -year doctoral student. “

After entering the school in 2019, in the next semester of research, Tang Jiadong will be Nanoscale And “Scientific Report” published an English review paper and Chinese schedule, respectively.

Although many results have been achieved, Tang Jiadong did not go well in the initial experimental progress of this subject, and the repeated failure of the synthesis of new materials has also depressed.

“In order to improve his confidence, I suggest that he stop the experiment first, calm down to check the information and consolidate the foundation. By this, he has a deeper understanding of the subject, and the experiment has begun to become smooth.Clatable film “Zhang Qianqian said.

In the end, the relevant papers take the title of “All-Natural 2D Nanofluidics As Highly-Efficient OSMOTIC ENERGY Generators” Nature communications[3].

Tang Jiadong and Wang Yun are common works. Zhang Qianqian, as well as Zheng Zilong and Mr. Gu Yifan of the same school served as the author of the common communication.

Figure | Related Paper (Source: Nature Communications)

At the same time, in the study, they found that there are still many problems with the current system, such as how to realize the high -throughput design of the sap membrane and how to improve the large -scale membrane power.

Therefore, they will build laminar -like mucous membranes with higher ions.

In addition, the current clay membrane has a two -dimensional layered structure.For ionic cross -membrane transmission, it is necessary to pass through the vertical laminate parallel channel and horizontal section intervertebral channel.

The tortuous transmission path is caused by high ion transmission resistance, which limits the further improvement of ionic flux.

In fact, this is also a common problem in the two -dimensional fluid membrane, and it is also the main reason why salt -poor power generation efficiency is difficult to get substantially improved.

In response to this problem, they will reduce the internal membrane resistance around the strategies such as reducing membrane thickness and increased vertical channel density, and strive to build high -throughput clay membranes, and truly improve the power generation capacity of salt difference.

At the same time, based on the economic, resources, and environmental benefits of all -natural clay membranes, they will continue to explore the large -scale preparation process of laminar mucous membranes.

Deliven to the use of natural raw materials and develop high -performance ions to choose through membrane materials to meet the application needs of energy fields and environmental fields.

Reference materials:

1.Nano Energy, 2020, 76, 105113

2.Nano Energy, 2022, 100, 107526

3..Nat. Commun., 2024, 15, 3649