Arrive for 19:00
Wednesday Feb 14, 2018
Entry is free. Members and non-members are welcome.
Carefully tailored porous micro-structures have a great possibility to give rise to substantially improved or unique properties that are not attained even in dense materials. In this context, ceramics with engineered porosity have been produced for a number of functional and structural applications such as thermal insulation, filters, catalysts and catalyst supports to lightweight structural components through various processing methods including partial sintering, replica template, sacrificial templating and direct foaming. These porous ceramics-based products enable us to successfully reach increasingly stringent environmental targets and provide efficient solutions to the growing energy crisis.
Sustainable energy is considered to be one of the grand research hot spots in today's word. Among all new energy resources, hydrogen is said to be the most promising future energy solution; great effort has been put into this field of research. However, searching for efficient and low-cost non-precious metal-based electrocatalysts for water splitting, include cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) remains a great challenge. Here we report a simple and organic solvent-free method that utilizes POMs in ZIFs as precursors for the one-step synthesis of tungsten sulfide/cobalt sulfide-codoped porous carbon nanocomposite as efficient electrocatalysts. POMs in ZIFs were synthesised via an in situ method so that phosphotungstic acid was encapsulated in the confined space of ZIF-67 during the formation of its crystals. This can prevent the agglomeration of metal elements during heat treatment and leads to a homogeneous dispersion of metal active sites within the carbon matrix. The resulting catalyst shows significant improvement in electrocatalytic activity towards both OER and HER. This work presents a new strategy to synthesis homogeneous transition metal sulfide decorated porous carbon nanostructures and open up a new way to obtain a bifunctional electrocatalysts towards OER and HER.
Cancer is one of the main challenges of the 21st century in developed countries. There are several techniques to identify and image it that have proved their capabilities for large cancer tissue. Unfortunately, when cancer spreads to large-scale structures, it can be too late to save a patient. There is an important need to find single cancer cells in the early-stages to improve rates of survival after applying a therapy. Nanoparticles functionalized with antibodies for cancer attachment have displayed the ability to image single cancer cells. This talk introduces a novel Au-SiO2-WO3 core-shell composite nanoparticle which displays strong cancer imaging capabilities via light scattering and potential for hyperthermia treatment. The more materials form the nanoparticle, the more useful properties can be used for a highly accurate cancer imaging and subsequent cancer therapy. These novel nanoparticles can broaden the horizons of biomedical material science in the upcoming decades.
We demonstrate strong coupling between plasmonic resonances and molecular vibrational resonances of polymethyl methacrylate (PMMA) molecules in the mid-infrared range through the use of grating coupling. Our work is complementary to earlier work using microcavities and localised resonances and provides a new approach by offering easy access to the coupled molecules. We will discuss the use of surface plasmon modes in strong coupling experiments, focusing on the open-cavity nature of these resonances, and the spatial variation of their optical field distribution. We will also highlight the opportunities they offer for fundamental studies of strong coupling involving molecular vibrational resonances.
A dye sensitized solar cell (DSSC) is a promising new solar cell because of its low-cost and easy operation. Compared with an engine using fossil fuel which causes serious environmental pollution or other traditional solar cells, the DSSC has advantages: nontoxicity, stability, high conversion efficiency and ease of manufacturing or recovery. Therefore, DSSC has been considered to be the best substitute to the traditional energy cell. A DSSC has a sandwich structure, and its working principle is driven by photoelectric effect. In overall process, sunlight is converted into electricity without materials consumption.
Since the DSSC was first reported with a poor conversion efficiency of 7% in 1991 year by O'Regan and Gratzel, researchers have improved the conversion efficiency of DSSCs up to 14%. (The conversion efficiency of traditional solar cell is 11% to 19%). Technically, the performance of DSSCs can be improved by altering single or multiple components of the cell such as semiconductor films, dyes, electrolytes, and counter electrodes. Moreover, researchers have attempted to improve its performance by using nanotechnology for photoanode (nano-TiO2). It has higher specific surface area and more reliable safe pathways property, which can increase the adsorption rate of dye and make electrons transfer more efficient. Currently, several types of nanoarchitecture are under investigation such as nanotubes, nanowires, hierarchical structures etc.
Nowadays, the commercial applications of DSSC has an enormous market potential. However, the main challenge is how to further improve the conversion efficiency without changing existing performance.