陈金星

！！！请参考英文版面点击右上方：English

Research

Our research focuses on the design, synthesis and application of functional nanomaterials. By using state-of-the-art characterization tools, we are trying to understand the formation mechanism and physiochemical properties of nanostructures, from which we can design and fabricate novel functional materials for various demanding applications. Specifically, our research topics include: 

• Precise synthesis of plasmonic and polymeric nanostructure; 

• Design of functional nanomaterials for Solar Energy Harvesting; 

• Solar-driven water evaporation and plastic upcycling

• Plasmonic Nanostructure vs Polymer
  

A localized surface plasmon (LSPR) is the result of the confinement of a surface plasmon in a nanoparticle of size comparable to or smaller than the wavelength of light used to excite the plasmon. When a small spherical metallic nanoparticle is irradiated by light, the oscillating electric field causes the conduction electrons to oscillate coherently. When the electron cloud is displaced relative to its original position, a restoring force arises from Coulombic attraction between electrons and nuclei. This force causes the electron cloud to oscillate. The oscillation frequency is determined by the density of electrons, the effective electron mass, and the size and shape of the charge distribution. The LSPRhas two important effects: electric fields near the particle's surface are greatly enhanced and the particle's optical absorption has a maximum at the plasmon resonant frequency. Surface plasmon resonance can also be tuned based on the shape of the nanoparticle. The plasmon frequency can be related to the metal dielectric constant. The enhancement falls off quickly with distance from the surface and, for noble metal nanoparticles, the resonance occurs at visible wavelengths. Localized surface plasmon resonance creates brilliant colors in metal colloidal solutions.

Localized surface plasmon resonance

We demonstrate that the synthesis challenge met in conventional ligand-based methods can be overcome by a robust confined seeded growth strategy, which allows for the production of high-quality samples with excellent control over their size, morphology, and plasmon resonance frequency. As an example, copper nanorods (CuNRs) are successfully grown in a limited space of preformed rod-shaped polymer nanocapsules, thereby avoiding the complex nucleation kinetics involved in the conventional synthesis. The method is unique in that it enables the flexible control and fine-tuning of the aspect ratio and the plasmonic resonance, making it convenient to satisfy the optical requirements in specific applications. We further show the high efficiency and stability of the as-synthesized CuNRs in photothermal conversion and demonstrate their incorporation into the fabrication of nanocomposite polymer films that can be used as active components for constructing light-responsive actuators and microrobots. The anisotropic copper nanostructures are believed to hold great potential to serve as effective plasmonic materials for a variety of practical applications, especially in areas where large-scale use of much more expensive gold and silver is prohibitive. 

Space-confined seeded growth of plasmonic nanostructure

• Solar-driven Water Evaporation

The need for clean, accessible water is one of the most pressing in the arsenal of environmental issues. As more people lose access to water and demand for potable water exceeds the available supply, methods of desalinating seawater become of greater importance. Current methods of desalination are comprised mainly of generally expensive reverse osmosis technologies, which are also inefficient, and energy-consuming. Interfacial solar steam generation is a modern alternative method of clean water production that utilizes a photothermal material floating on the surface of water that harnesses solar energy to boost evaporation. This technique increases solar energy utilization efficiency by heating only the top layer of the water, thus avoiding bulk heating and energy loss.

Solar-driven water evaporation