Recently, the research team led by Prof. Zhang Yuanjian from School of Chemistry and Chemical Engineering of Southeast University and Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, and Prof. Ma Haibo from School of Chemistry and Chemical Engineering of Nanjing University, jointly reported the progress on fundamental molecular active units in carbon nitride. The results, titled "Unraveling Fundamental Active Units in Carbon Nitride for Photocatalytic Oxidation Reactions", were published in Nature Communications, a major international journal.
It has been the key to the technological and scientific development to converse energies of variegated forms. For instance, photoelectrochemistry based on the light-to-electricity conversion and electrochemiluminescence based on the electricity-to-light conversion, have been widely applied in the highly sensitive detection of related markers for more than 100 clinical diseases (including cancer), among which developing high performance photoactive and electroactive materials laid the material foundation for optoelectronic sensing.
Carbon nitride, as a two-dimensional polymer material with the graphite-like structure, is featured by excellent physical and chemical stability, unique chemical structure and electronic band structure, thus making itself a common material in the fields of artificial leaf (photosynthesis), industrial catalysis, etc. In the early work, the team has gone in a different direction and found that carbon nitride features a very attractive application prospect in optoelectronic sensing. Therefore, they developed a new method of ultra-high sensitivity photoelectric detection for small molecules and markers related to a variety of diseases, such as DNA damage, with carbon nitride. On this basis, the team also went deeper to explore the importance of fundamental active units of carbon nitride in the photochemical and electrochemical reaction process at the molecular level, so as to further promote the rational preparation of carbon nitride and exploit its superb photoelectric characteristics for better sensing property. However, given the extremely complex molecular structure of carbon nitride, this research was fraught with challenges.
In response to this challenge, the team has successfully separated and identified two basic molecular units of carbon nitride, namely the distinguishable melem (M1) and its incomplete condensed form (M2), through microwave synthesis, mass spectrometry and other synthesis and characterization measures. In addition, they also advanced with experimental and theoretical calculations, and revealed the leading role of M1 and M2 in light absorption and charge separation respectively in the whole processes of photocatalytic oxidation. Meanwhile, the O2 substrate participated in the photoexcited processes via an electronic coupling with M2. It can be concluded that the more detailed understanding of the critical roles of each fundamental active unit and their synergistic effects would substantially pave the way for rational bottom-up preparation and practical applications of carbon nitride and other emerging polymeric photocatalysts as well in optoelectronic sensing, energy conversion, environmental governance, etc.
For this paper, Huang Chaofeng and Ma Jin, doctoral students from Southeast University, and Wen Yaping, a doctoral student from Nanjing University are the co-first authors, with Zhang Yuanjian and Ma Haibo as the corresponding authors, and Southeast University as the first accomplishment institute. Meanwhile, this research was funded by both the National Natural Science Foundation of China and the Innovative and Entrepreneurial Team Project of Jiangsu Province.
The paper's link:
https://doi.org/10.1038/s41467-020-20521-5
Submitted by: School of Chemistry and Chemical Engineering
Translated by Melody Zhang
Revised by Song Chunyi
Proofread by Eric Song
Edited by Sha Lu