Professor Dai’s research spans chemistry, physics, and materials and biomedical sciences, leading to materials with properties useful in electronics, energy storage and biomedicine. Recent developments include near-infrared-II fluorescence imaging, ultra-sensitive diagnostic assays, a fast-charging aluminum battery and inexpensive electrocatalysts that split water into oxygen and hydrogen fuels.
Born in 1966 in Shaoyang, China, Hongjie Dai began his formal studies in physics at Tsinghua U. (B.S. 1989) and applied sciences at Columbia U. (M.S. 1991). He obtained his Ph.D. from Harvard U and performed postdoctoral research with Dr. Richard Smalley. He joined the Stanford faculty in 1997, and in 2007 was named Jackson–Wood Professor of Chemistry. Among many awards, he has been recognized with the ACS Pure Chemistry Award, APS McGroddy Prize for New Materials, Julius Springer Prize for Applied Physics and Materials Research Society Mid-Career Award. He has been elected to the American Academy of Arts and Sciences, National Academy of Sciences (NAS), National Academy of Medicine (NAM) and Foreign Member of Chinese Academy of Sciences.
The Dai Laboratory has advanced the synthesis and basic understanding of carbon nanomaterials and applications in nanoelectronics, nanomedicine, energy storage and electrocatalysis.
The Dai Lab pioneered some of the now-widespread uses of chemical vapor deposition for carbon nanotube (CNT) growth, including vertically aligned nanotubes and patterned growth of single-walled CNTs on wafer substrates, facilitating fundamental studies of their intrinsic properties. The group developed the synthesis of graphene nanoribbons, and of nanocrystals and nanoparticles on CNTs and graphene with controlled degrees of oxidation, producing a class of strongly coupled hybrid materials with advanced properties for electrochemistry, electrocatalysis and photocatalysis. The lab’s synthesis of a novel plasmonic gold film has enhanced near-infrared fluorescence up to 100-fold, enabling ultra-sensitive assays of disease biomarkers.
Nanoscale Physics and Electronics
High quality nanotubes from his group’s synthesis are widely used to investigate the electrical, mechanical, optical, electro-mechanical and thermal properties of quasi-one-dimensional systems. Lab members have studied ballistic electron transport in nanotubes and demonstrated nanotube-based nanosensors, Pd ohmic contacts and ballistic field effect transistors with integrated high-kappa dielectrics.
Nanomedicine and NIR-II Imaging
Advancing biological research with CNTs and nano-graphene, group members have developed π–π stacking non-covalent functionalization chemistry, molecular cellular delivery (drugs, proteins and siRNA), in vivo anti-cancer drug delivery and in vivo photothermal ablation of cancer. Using nanotubes as novel contrast agents, lab collaborations have developed in vitro and in vivo Raman, photoacoustic and fluorescence imaging. Lab members have exploited the physics of reduced light scattering in the near-infrared-II (1000-1700nm) window and pioneered NIR-II fluorescence imaging to increase tissue penetration depth in vivo. Video-rate NIR-II imaging can measure blood flow in single vessels in real time. The lab has developed novel NIR-II fluorescence agents, including CNTs, quantum dots, conjugated polymers and small organic dyes with promise for clinical translation.
Electrocatalysis and Batteries
The Dai group’s nanocarbon–inorganic particle hybrid materials have opened new directions in energy research. Advances include electrocatalysts for oxygen reduction and water splitting catalysts including NiFe layered-double-hydroxide for oxygen evolution. Recently, the group also demonstrated an aluminum ion battery with graphite cathodes and ionic liquid electrolytes, a substantial breakthrough in battery science.
Lin, M.-C., Gong, M., Lu, B., Wu, Y., Wang, D.-Y., Guan, M., … Dai, H. (2015). An ultrafast rechargeable aluminium-ion battery. Nature, 520(7547), 325–28.
Javey, A., Guo, J., Wang, Q., Lundstrom, M., & Dai, H. J. (2003). Ballistic carbon nanotube field-effect transistors. NATURE, 424(6949), 654–57.
Kam, N. W. S., O'Connell, M., Wisdom, J. A., & Dai, H. J. (2005). Carbon nanotubes as multifunctional biological transporters and near-infrared agents for selective cancer cell destruction. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 102(33), 11600–11605.
Li, X., Wang, X., Zhang, L., Lee, S., & Dai, H. (2008). Chemically derived, ultrasmooth graphene nanoribbon semiconductors. SCIENCE, 319(5867), 1229–32.
Liang, Y., Li, Y., Wang, H., Zhou, J., Wang, J., Regier, T., & Dai, H. (2011). Co3O4 nanocrystals on graphene as a synergistic catalyst for oxygen reduction reaction. NATURE MATERIALS, 10(10), 780–86.
Hong, G., Lee, J. C., Robinson, J. T., Raaz, U., Xie, L., Huang, N. F., … Dai, H. (2012). Multifunctional in vivo vascular imaging using near-infrared II fluorescence. NATURE MEDICINE, 18(12), 1841-?
Kong, J., Franklin, N. R., Zhou, C. W., Chapline, M. G., Peng, S., Cho, K. J., & DAI, H. J. (2000). Nanotube molecular wires as chemical sensors. SCIENCE, 287(5453), 622–25.
Chen, R. J., Zhang, Y. G., Wang, D. W., & DAI, H. J. (2001). Noncovalent sidewall functionalization of single-walled carbon nanotubes for protein immobilization. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 123(16), 3838–3839.
Fan, S. S., Chapline, M. G., Franklin, N. R., Tombler, T. W., Cassell, A. M., & DAI, H. J. (1999). Self-oriented regular arrays of carbon nanotubes and their field emission properties. SCIENCE, 283(5401), 512–514.
Kong, J., Soh, H. T., Cassell, A. M., Quate, C. F., & Dai, H. J. (1998). Synthesis of individual single-walled carbon nanotubes on patterned silicon wafers. NATURE, 395(6705), 878–881.