Introduction to the results:

 The Institute of Applied Technology has selected and optimized a series of new visible light-responsive photocatalysts. Combined with existing mature adsorption and filtration technologies such as activated carbon and HEPA, a prototype of a photocatalytic air purifier has been developed. This purifier can not only effectively filter out particulate matter such as PM2.5, but also efficiently degrade VOCs such as formaldehyde and toluene. The degradation efficiency is two to three times that of similar products on the market (using TiO2 as a photocatalyst).

 Based on preliminary work, this project will develop high-activity and high-stability visible light catalyst formulas, develop new photocatalytic air purifiers using LEDs as excitation light sources, and conduct performance evaluation and demonstration applications. It also seeks to cooperate with air purifier companies or social capital to promote the transfer and transformation of photocatalytic air purifiers and make positive contributions to the industrialization process of air purification and the high-level development of my country's environmental economy.

Necessity and needs analysis:

 With economic development and social progress, environmental pollution problems have become increasingly serious. Volatile organic compounds (VOCs) are the main pollutants in the atmosphere, and part of their sources come from outdoors, mainly industrial exhaust gas, motor vehicle exhaust, photochemical smog, etc.;

 The other part comes from the interior. Decoration and decoration materials such as paints and their solvents, wood preservatives, coatings, plywood, etc. can release various volatile organic substances such as toluene and formaldehyde at room temperature. Due to the poor mobility of air in the indoor environment, accumulated pollutants pass through human breathing and skin, causing serious harm to the human body.

 Taking formaldehyde as an example, if the human body leaks in an atmosphere of formaldehyde with a concentration greater than 0.1 mg/m3 for a long time, it will cause dizziness and audio-visual obstruction. In severe cases, it will cause damage to the respiratory system, cardiovascular and cerebrovascular diseases, etc. The mixed existence of multiple VOCs and their mutual chemical interactions will also increase the intensity of the hazard. Therefore, improving indoor air quality through purification technology is of great significance to people's health.

Existing work foundation:

 The project team has been engaged in semiconductor photocatalysis for a long time, and has accumulated rich experience in the development of new visible photocatalysts, the design and synthesis of high-efficiency composite photocatalysts, and the mechanism of photocatalytic degradation of volatile organic pollutants. Related work has been published in Nanoscale, Appl Catal B, ACS Appl Mater Interfaces, J Phys Chem C, Catal Lett and other famous journals, and has applied for national invention patents.

Expected economic and social benefits:

 In 2014, the total sales of air purifiers in my country reached 3.6 million units, and sales exceeded 9 billion yuan. In 2015, the annual domestic output value of the indoor environmental protection industry, including air purifiers, is expected to reach 80 billion yuan. Despite the rapid development of the air purifier market, compared with Western developed countries, the penetration rate of air purifiers in my country is still extremely low-the penetration rate of American households reaches 27%, and the penetration rate in public places and family rooms in Canada, Japan and other countries is also above 15%; while in my country, the penetration rate is only 0.1%, which means a huge market with great imagination.