There is a "shadow killer" in the newly renovated house. Who has found the "nemesis" to subdue it?

Colorful wallpaper, brand new furniture, clean floors... The newly renovated house is so beautiful, I really want to move in right away. Wait a minute! Maybe you don’t know that there may be many "shadow killers" lurking in the newly renovated house, especially the "number one killer" that makes everyone shudder - formaldehyde.

Image source: Pixabay

What is formaldehyde?

Formaldehyde is a substance that is very harmful to the human body. It has no color, and its odor is irritating but not easy to identify. It can attack people's immune system invisibly. If excessive formaldehyde is inhaled, people will experience symptoms such as severe coughing, difficulty breathing, nausea and vomiting, and even cause memory and intelligence decline in teenagers.

What’s even more disgusting is that formaldehyde is everywhere. New clothes, cosmetics, even some foods and polluted air may contain formaldehyde!

What a rampant formaldehyde! Is there really nothing people can do about it?

Of course not! Scientists have found its nemesis, which is photocatalysis.

Photocatalysis? It sounds like it has some similarities with the photosynthesis that everyone is familiar with.

That's right! Photosynthesis is the process of converting water and air (mainly carbon dioxide) into organic matter and releasing oxygen under the irradiation of sunlight through the catalyst of chlorophyll.

The process of photocatalysis is exactly the opposite of photosynthesis. Under the action of sunlight, photocatalysts convert organic matter (such as formaldehyde) into carbon dioxide and water.

It seems that photocatalyst is the “number one hero” in “eliminating” formaldehyde!

So how does the photocatalyst “eliminate” formaldehyde?

Normally, photocatalysts are very quiet soldiers, but once exposed to sunlight, they become very excited and can mobilize the excitement of surrounding oxygen and water molecules, turning them into highly oxidizing active oxygen. When formaldehyde encounters active oxygen, it is like a bug hitting a spider web. Not only does it have no way to escape, it is also turned into non-toxic carbon dioxide and water.

After completing the task, the photocatalyst "calms down" and "obediently" returns to its original state without any consumption of its own.

So, is the “combat power” of photocatalyst very strong? Let me tell you, there are even more powerful ones!

Photocatalysts can not only decompose formaldehyde, but also other pollutants into water and carbon dioxide, and can destroy bacterial cell membranes and viral proteins, thereby killing bacteria and viruses. Therefore, it can "show its prowess" in air purification, water purification, self-purification, sterilization and deodorization, anti-fouling and anti-fogging, etc.

See, photocatalysts and photocatalytic technology have so many uses, and we really need to use them properly! However, 20 or 30 years ago, our country had no photocatalytic technology at all.

It is hard to imagine how difficult it is to achieve a breakthrough from 0 to 1. However, one scientist decided to rise to the challenge. He is Academician Fu Xianzhi, who is known as the "Father of Chinese Photocatalytic Technology".

In 1997, Fu Xianzhi returned from studying abroad and began his photocatalytic research. At that time, in order to retain this outstanding Chinese scholar, the foreign party put forward many conditions: "outstanding scientist" status, permanent residence permit (green card), high salary, etc. However, these did not shake Fu Xianzhi's determination to return to China. He believed that he went abroad to see how others did scientific research, learn advanced scientific research methods from them, and return to serve the motherland. He even took his son's textbooks from grade one to grade five with him, so that his children's homework could be connected with that in China after returning home. He also often told his family: I must return to China to build a laboratory after I finish my studies.

Now, we have a laboratory, but how can we conduct research in such a simple hut of only 20 square meters with only one instrument?

Do we have to wait for scientific research funds to "drop from the sky"? Can we not do research without advanced instruments? Fu Xianzhi doesn't think so! He did it right away, and with a few young people, he plunged into this small laboratory and began to study photocatalytic technology.

Doing experiments, working in the workshop, and working on one project after another... Fu Xianzhi regards this small laboratory as his home. He said: Scientific research is done step by step.

Finally, Fu Xianzhi walked out of his former shabby hut step by step and established the first research institute in the field of photocatalysis in my country - Fuzhou University Photocatalysis Research Institute.

The wish was finally realized, but Fu Xianzhi, who loved research, did not stop there. He turned his attention to the application field of photocatalysis.

If the scientific research results are applied to real life, wouldn’t it be useful for the country and the people? How great it would be if we could make China’s own photocatalytic products! Fu Xianzhi thought so and did so.

In 2002, Fu Xianzhi successfully developed China's first photocatalytic air purifier, filling the gap in the application of photocatalytic technology in my country.

During the fight against SARS in 2003, he led his team to develop photocatalytic air purifiers and photocatalytic antibacterial masks, which were used for disinfection and protection of designated hospitals for SARS treatment in Beijing, making an important contribution to the fight against SARS.

The effects of photocatalysis are far more than that!

During the Beijing Winter Olympics, photocatalysis was one of the top ten innovative high-tech disinfection technologies. This ultraviolet photocatalytic compound disinfection machine is a new achievement of Fu Xianzhi's team. It can disinfect 99.9% of germs in just 5 seconds, which is a major breakthrough in this field in China. It is also very practical because it is convenient, fast, and does not pollute the environment.

When talking about the prospects of photocatalysis, scientists like Fu Xianzhi are filled with pride and passion. They firmly believe that as long as they work hard, photocatalysis will surely benefit mankind better and change the world!

What else can photocatalysis do? What other magical functions does it have? These answers are waiting for you to explore and discover!

Source: Chongqing Industry-University-Research Cooperation Promotion Association

Author: Pan Fusheng, Academician of the Chinese Academy of Engineering, Professor of Chongqing University, Chairman of Chongqing Association for Science and Technology

Review expert: Mao Yi, chief expert of Chongqing Science Communication Expert Group, professor of Chongqing Electronic Engineering Vocational College

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