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Research Projects in the Chen GroupRESEARCH THEME: ELECTRON TRANSFER ON THE NANOSCALE
Janus Nanoparticles by Interfacial Engineering. In this project our interest is to develop effective experimental protocols for the preparation of functional nanoparticles with an asymmetrical structure, such as Janus nanoparticles, and Neapolitan nanoparticles. These structurally asymmetrical nanoparticles behave analogously to conventional amphiphilic surfactant molecules and can self-assemble into organized ensembles, leading to the emergence of new optical and electronic properties, such as plasmonic circular dichroism, that may be exploited for the sensitive detection and separation of select optical enantiomers.
Charge Transfer Dynamics at Nanoparticle-Ligand Interface. Both metal (e.g., Ru, Pt, Au, Pd, etc) and semiconductor (e.g., Si, TiO2, etc) nanoparticles are generally capped with select organic ligands for structural stabilization and surface functionalization. Whereas mercapto derivatives have been used extensively as the ligands of choice, the resulting interfacial bonds are rather polar, which inhibits the core-ligand interfacial charge transfer. By contrast, with the formation of conjugated nanoparticle-ligand interfacial bonds by virtue of, for instance, carbene, acetylene,and nitrene derivatives, effective charge delocalization occurs at the interface. This leads to the emergence of new electronic states/propreties that have significant implication in the nanoparticle materials properties and applications, such as electrocatalysis and photocatalysis. Current research interest is focused on the development of new chemistry for nanoparticle surface engineering.
Nanostructured Catalysts for Electrochemical Energy Technologies. Our interest in this research project is to develop low-cost, high-performance catalysts for important reactions in a range of electrochemical energy technologies, such as fuel cells, microbial fuel cells, (metal-air, lithium-sulfur) batteries, water splitting, supercapacitors, etc. One effective strategy is to design and engineer single metal-atom catalysts embedded within a carbon matrix, where the coordinating chemistry between the metal centers and the carbon skeletons leads to the generation of catalytic active centers. The key to the success of the research endeavors is to combine theory with experiments so that the mechanistic origin can be unambiguously defined.
Antimicrobial Activity of Functional Nanomaterials. As antibiotic resistant strains of pathogenic bacteria become increasingly prevalent and cause widespread infection in communities around the world, the development of novel, highly potent antibacterial reagents has become vital to world health. Functional nanoparticles represent a viable candidate because of their unique optical and electronic properties that can be tailored by the composition, morphology, interfacial functionalization, etc, for optimal bactericidal activities.