Recently, academician of the Chinese Academy of Sciences and researcher of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences Li Can, etc., used the space-resolved surface photovoltage spectrum and the Kelvin probe imaging system independently researched and developed to study the role of cocatalysts in the conversion process of solar fuels, and found that nanoscale cocatalysts can be The direction and size of the built-in electric field of the photocatalytic material are effectively controlled, and a built-in electric field of up to 2.5 kV/cm is formed at the interface, and the local photovoltage value can be enhanced by 80 times. The study revealed a new mechanism by which cocatalysts enhance photocatalytic and even thermocatalytic performance. The paper was published in Nano Letters. Cocatalysts are important components in the process of photocatalytic and photoelectrocatalytic conversion of solar energy to chemical energy. The vast majority of photocatalytic systems require the introduction of cocatalysts to enhance the photocatalytic activity. The cocatalysts are used in the above conversion process. The role played in it is not clear. One of the reasons is that in the photocatalytic process, photo-generated charge plays an important role in the reaction of most of the catalytic reaction elementary steps, so the improvement of photocatalytic properties cannot be simply attributed to the surface reaction kinetics promoted by the catalytic reaction. . Using self-developed spatially resolved surface photovoltage spectroscopy and a Kelvin probe imaging system, the research team found that the hole transfer at the interface between the cocatalyst and the photocatalytic material was enhanced after deposition of the cocatalyst on the model system represented by BiVO4. The direction of the built-in electric field in the area where the co-catalyst was not supported was reversed, and the strength was improved. The experimental data and numerical simulation results further indicate that the introduction of the cocatalyst effectively increases the size of the space charge layer, making it from the original two independent opposite built-in electric fields into a built-in electric field connected to each other and in the same direction. Charge separation ability. In addition, studies have found that the use of dual cocatalysts has the synergistic effect of increasing the built-in electric field. Surface photovoltage imaging studies have shown that the introduction of a cocatalyst forms an electric field of up to 2.5 kV/cm at the interface, effectively separating electrons and holes in space. This result and previous studies (Angew. Chem. Int. Ed., JPCL,) embody the systematic nature of photocharge charge imaging research and reveal the decisive role of the built-in surface of the lift table interface in constructing a highly efficient solar fuel conversion process. The research work was supported by the 973 project of the Ministry of Science and Technology, the National Natural Science Foundation of China, the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences and the Ministry of Education's Energy and Material Chemistry Collaborative Innovation Center (iChEM). Ernte | Automatic Coffee Machines,Fully Automatic Coffee Machine,Automatic Espresso Coffee Maker,Best Automatic Coffee Makers SUN YAT INDUSTRY LIMITED , https://www.ernte-eu.com
Dalian Institute of Materials for Photocatalytic Co-catalyst Regulates Imaging of Built-in Electric Field