Solar photocatalytic reaction can decompose water to generate hydrogen, reduce carbon dioxide, and generate solar fuel, which will open a new way to obtain clean energy. But for more than half a century, the basic mechanism of this process has been unclear. Now, this mystery has been revealed by Academician Li Can and Researcher Fan Fengtao of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences (hereinafter referred to as "Dalian Institute of Chemical Physics") - researchers have integrated a variety of technologies that can be connected at the time and space scale to detect the photogenerated charge transfer of photocatalyst nanoparticles in full time and space, revealed the complex multiple charge transfer mechanism, and "photographed" the whole time and space image of the evolution of photogenerated charge transfer. The evidence of "seeing is believing" made scientists clear the essential relationship between charge separation mechanism and photocatalytic water decomposition efficiency, providing new understanding and research strategies for breaking the "bottleneck" of solar photocatalytic reaction. Relevant research results were published in the international academic journal Nature on October 12. Li Can introduced that the core scientific challenge of photocatalytic water decomposition lies in how to achieve efficient separation and transmission of photogenerated charges. "Because this process spans a huge space-time scale from femtosecond to second and from atom to micrometer, it is extremely challenging to uncover the micro mechanism of this whole process". In order to uncover this mystery, the research team has integrated a variety of advanced characterization technologies and theoretical simulations. Fan Fengtao introduced, for example, in order to achieve efficient charge separation, researchers selectively synthesized a specific defect structure to a specific crystal plane of particles, forming a directional rearrangement electric field; In order to better understand the mechanism of efficient charge separation in the nanosecond range, time resolved light emission electron microscopy was used; Later, researchers analyzed the charge transfer process using transient photovoltage, and found that with the development of the time scale from nanosecond to microsecond, holes gradually appeared on the crystal plane containing the defect structure. In this way, the researchers "photographed" the long lens of the micro world, revealing the mystery of the photolytic water catalyst. "Like the relay race, we are tracking the whole mechanism of electrons and holes to the surface reaction center in a photocatalyst particle for the first time," said Li Can, "The ability to track charge transfer in time and space will greatly promote the understanding of complex mechanisms in the energy conversion process, and provide new ideas and research methods for rational design of photocatalysts with better performance." Li Can said: "In the future, this achievement is expected to promote the application of solar photocatalytic decomposition of water to produce solar fuel in real life, and provide clean and green energy for our production and life." (Outlook New Times Network)