On September 16, 2025, Professor Zhang Liwu from Fudan University delivered an academic report titled “Chemistry at the Air–Liquid Interface of Microdroplets and Its Environmental Significance” for the faculty and students of our institute. The report was held in Conference Room E202 of the School of Environment and was presided over by Professor Tang Changjin from the School of Environment. More than 40 teachers and students attended the report.

Professor Zhang Liwu is a second-level professor and doctoral supervisor at Fudan University, and the Deputy Director of the Department of Environmental Science and Engineering (a university-level department). He obtained his Ph.D. from the Department of Chemistry at Tsinghua University and conducted postdoctoral research at the Department of Physics at the University of Cambridge before returning to China. His research primarily focuses on the field of environmental particulate pollution. To date, he has published over 160 academic papers in renowned journals such as Sci. Adv., PNAS, JACS, Angew, and EST, with more than 12,000 citations by others. He has been selected into the National High-Level Talent Introduction Program and has presided over key special projects of the National Key R&D Program in the field of international cooperation. He serves as the associate editor of the Royal Society of Chemistry journal Environ Sci: Adv and a member of the editorial board of Proceedings A of the Royal Society (founded in 1800). He has received awards including the First Prize in Natural Science from the Ministry of Education, the Royal Society International Collaboration Award, the Chinese Chemical Society Young Environmental Chemistry Award, the Humboldt Research Fellowship from Germany, and the Marie Skłodowska-Curie Fellowship from the European Union.

Professor Zhang Liwu provided an in-depth introduction to the research background of atmospheric particulate pollution control, pointing out that the treatment of secondary pollutants is crucial in the current studies of atmospheric chemical processes, with the chemical mechanisms at the air–liquid interface being the focal point of research. To address the challenge of “the uniqueness of the air–liquid interface and the limitations of existing research methods restricting the study of interfacial mechanisms,” Professor Zhang Liwu’s team established a spectroscopic measurement and imaging method at the microscopic level of the air–liquid interface. This method overcame the slow imaging speed of traditional Raman spectroscopy. By developing stimulated Raman techniques, the team achieved three-dimensional chemical imaging of individual atmospheric particles, obtaining important information such as the composition and mixing states of the particles. The team also tackled the difficult problem of directly measuring the acidity of individual aerosols, discovering a pH gradient distribution within atmospheric microdroplet aerosols, which breaks through traditional understanding. In addition, Professor Zhang Liwu introduced the team’s findings on the photochemical reaction mechanisms at the air–liquid interface, revealing that the strong electric field at the air–liquid interface of microdroplet aerosols can significantly accelerate the rapid formation of secondary sulfates in the atmosphere. Finally, the team elucidated the mechanism by which air–liquid interface effects lead to the formation of secondary pollutants, proposing a new mechanism in which partial solvation effects accelerate the formation of sulfates.

After the report, the faculty and students of our institute had an enthusiastic exchange and discussion with Professor Zhang Liwu on a number of cutting-edge issues. The faculty and students actively raised questions, which covered topics such as the research progress on more complex chemical substances like dust particles, the spectroscopic measurement methods of microdroplets, the impact of surface concentration changes on the rate of chemical reactions, and the capability development during the master's and doctoral studies. Professor Zhang Liwu provided detailed answers to these questions one by one. The academic atmosphere at the report site was very strong, which broadened the students' research horizons and inspired their thinking.