In recent years, with the transitional development and utilization of fossil energy, it has led to the transitional emission of CO2, seriously affected the balance of carbon cycle in nature, and brought very serious environmental problems, especially the climate change caused by the greenhouse effect. CO2 reduction reaction (co2rr) is an effective way to synthesize high value-added chemicals from excessive CO2 emissions. This process can not only reduce the content of CO2 in the atmosphere, but also store renewable energy in the reduction products for reuse and maintain the carbon balance in nature. However, CO2 molecules are very stable (804.4 kJ mol-1), and the conversion of CO2 to hydrocarbon products is a non spontaneous reaction (? G & gt; 0), which makes the reduction of CO2 very difficult. Photocatalytic CO2 reduction provides us with a new idea. "Photocatalytic CO2 reduction" refers to the reduction of CO2 into carbon compounds such as carbon monoxide, methane, ethylene, etc. by using solar energy. These carbon compounds are the stable, efficient and clean energy for people's daily use. In this way, we can not only alleviate the global energy crisis, but also realize the "carbon cycle", and apply the excessive CO2 in the atmosphere to industrial life.
Zhang Jiatao research team of Beijing University of science and technology, aiming at the performance tailoring of plasma enhanced photocatalyst, realized the performance leap from metal / semiconductor heterogeneous nanocrystalline photocatalytic hydrogen production (her) to co2rr by using the original non epitaxial growth method and epitaxial growth method. The Au / CdSe hetero nanocrystals with dumbbell structure were first synthesized by reverse competitive cation exchange reaction. The results show that Au / CdSe heterostructure nanocrystals have a single crystal CdSe semiconductor shell, a clear metal semiconductor interface, and plasma enhanced hot electron injection efficiency and high her activity. The researchers further regulated the performance of photocatalyst, and obtained the Au / cdse-cu2o multilayer heterogeneous nanocrystals with clear heterogeneous interface by epitaxial growth. The Cu2O shell on the periphery of the multilayer heterostructure can effectively inhibit the her process, so the Au / CdSe Cu2O multilayer heterostructure has high co2rr activity, and the selectivity of its carbon containing products is as high as 100%. It is found that the product of photocatalytic reduction of CO2 is closely related to the photocatalytic reaction conditions. Under the condition of high selectivity of carbon containing products, the ratio and yield of CO and CH4 can be effectively adjusted by adjusting the content of H2O in the photocatalytic reaction system. The results show that CdSe and Cu2O in the multi-layered heterogeneous nanocrystals form a Z-scheme heterostructure, which promotes the separation of photogenerated charge and improves the performance of photocatalytic reduction of CO2. The LSPR effect of Au nanorods improves the light absorption performance of the whole photocatalyst, and provides an electric field environment to accelerate the photogenerated charge transfer; the Cu2O around the heterogeneous nanostructure has rich oxygen vacancy and hydroxyl groups, which improves the adsorption performance of CO2 and provides abundant active sites for the photocatalytic reaction; the CdSe semiconductor in the middle, as a bridge of photogenerated charge transfer, improves the photo generated charge transfer performance The transmission efficiency of photogenerated charge is obtained. Under the optimal photocatalysis conditions, the stable rate of CO and CH4 formation in Au / cdse-cu2o multilayered heterogeneous nanocrystals within 60 hours is 254 and 123 μ mol g-1 H-1, respectively. Related papers were published online in small (DOI: 10.1002 / small. 202000426).
Guess you like it
Small: hybrid protein nanoreactor is used to enhance radionuclide therapy for AFM: drug loaded fiber gel for tumor chemotherapy and immunotherapy and prevention of recurrence after tumor surgery.
(click the above title to read the original)
MaterialsViewsChina
Official wechat platform
Focus on new information of materials
Material Daniel vs rookie interview
MVC paper ranking list is newly published every month
What are you waiting for? Join us for micro interaction!!!
Microsignals: materialsviews
Microblog: materialsviews China
You are welcome to forward and share. Please contact:
materialsviewschina@wiley.com
Pay attention to the cutting edge of material science, please long press the identification QR code
Click "read original" in the lower left corner to read small original