CHEM Seminar - Sculptured Nano Forests
Speaker: Professor Zhifeng HUANG
Institution: Department of Physics, Hong Kong Baptist University
Hosted by: Professor Benzhong TANG
Abstract
One-dimensional nanopillar arrays (i.e., nano forests) exhibit unique electric, optic, optoelectronic, and mechanic properties, leading to a wide range of prominent applications. To develop these potential applications, it is of fundamental importance to engineer materials and structures of nano forests. Glancing angle deposition (GLAD), an unique physical vapor deposition performed at a glancing incident angle typically larger than 80° with respect to the substrate normal, enables one-step deposition of nano forests over macroscopic area, sculpture of nanopillar structures, and engineering of nanopillar materials (such as metals and semiconductors). Hence, GLAD enables the fabrication of sculptured nano forests (SNAFs), due to the self-shadowing effect and adatomic diffusion.
In this talk, I will introduce some current investigations of SNAFs in the chirality-related fields. My group used GLAD to generate the SNAFs composed of metallic chiral nanoparticles (CNPs), which have inherent chiral lattices at the atomic scale and plasmonic optical activity. Composition space of metallic CNPs have been extended from the unary to binary, trinary and so on, and the morphology has been engineered in solid and mesoporous. Importantly, we found enantioselecive adsorption of molecules on the CNPs and the possibility to amplify optical chirality of near field scattering via the chiroplasmonic effect. Such a flexible engineering of the CNPs with respect to element type, composition and morphology, together with the unique surface adsorption effect and the chiroplasmonic effect, leads to applying metallic CNPs to sensitively enantiodifferentiate an enantiomer and its mirror image, mediate photo-induced asymmetric cyclodimerization of a prochiral anthracene derivative, and enhance the refractive index sensitivity of the plasmonic medium. These works provide an insight to develop the promising applications of metallic CNPs in the fields of bio-detection, bio-imaging, and heterogenous asymmetric catalysis.
About the speaker
Dr. Zhifeng Huang obtained B.Sc. in Chemistry (in 2000) and M.Sc. in Physical Chemistry (in 2003) at Xiamen University (China), and Ph.D. in Science and Engineering of Materials at Arizona State University (US, 2007). After working as a postdoctoral fellow in Department of Electrical and Computing Engineering at University of Alberta (Canada, Jan. 2008 – Aug. 2009), Dr. Huang joined Department of Physics at Hong Kong Baptist University (HKBU) as an Assistant Professor, and was promoted to Associate Professor in 2015.
Dr. Huang is Associate Director (Nanomaterials) in Golden Meditech Centre for NeuroRegeneration Sciences at HKBU, is Member of The Hong Kong Young Academy of Sciences, and serves as Vice President in Hong Kong Materials Research Society.
Dr. Huang is devoted to fabricating sculptured nano thin films to study chiral nanoplasmonics, surface enhanced chiroptical spectroscopies, enantioselective synthesis, photochirogenesis, enantiodifferentiation, trace (bio)molecular detection, bio-nano interaction, specific differentiation of stem cells, functional optic coating, and flexible/wearable energy generation and storage. He contributed to two book chapters, and published his studies in high-impact journals, such as Nat. Nanotechnol., Annu. Rev. Phys. Chem., Adv. Mater., Adv. Funct. Mater., Nano Lett., J. Am. Chem. Soc., Adv. Sci., Small, and Nanoscale.
Dr. Huang was presented 2019 TechConnect Innovation Award, Gold Medal with Congratulations of Jury (The 46th International Exhibition of Inventions of Geneva, 2018), Outstanding Research Achievement (APSMR, 2017 and 2018), the Prof. Rudolph A. Marcus Award 2016, the Incentive Award for Outstanding Research Achievement (Faculty of Science, HKBU, 2015), and National-level Technology Project Award for Advanced Individual (2012, 2014). He is serving as Review Editor for Frontiers in Chemistry, Associate Editor for Science Advances Today and Science Letters Journal (Cognizure).
Dr. Huang, together with Prof. Ken Yung (Department of Biology, HKBU), co-founded a spin-off, Mat-A-Cell Ltd., to commercialize a new-generation medical device for cell culture.