Assoc.Prof. Guohua Xie
Department of Chemistry, Wuhan University
Title: Thermally Activated Delayed Fluorescence Emitters for High-Performance Solution-Processed Organic Light-Emitting Devices
Abstarct: Thermally activated delayed fluorescence (TADF) materials are the emerging emitters for organic light-emitting devices (OLEDs) which could realize 100% exciton utilization in the optimal conditions. To meet the requirements of low-cost and mass-production for practical application, we developed a series of highly efficient TADF small molecules, dendrimers, and polymers.
TADF small molecules were designed and synthesized by isomer engineering. It was found that the meta-linking could simultaneously result in a high photoluminescence quantum yield and a high electroluminescent efficiency via solution-process.
Carbazole-dendronized emitters with a TADF core were developed. We disclosed the hidden exciplex emission along with the TADF mechanism. By optimizing the electron transporting layer, a high electroluminescent efficiency with a tiny efficiency roll-off was demonstrated with the non-doped dendrimer as the emitting layer.
Side-chain engineering was applied to develop a series of TADF polymers, in which a TADF small molecule was grafted as the side-chain component. By introducing an additional TADF small molecule with a PLQY of ~100% as the sensitizer, a high PLQY of 95% in the ternary-blend film were demonstrated. This strategy has been proven as a universal approach to designing highly efficient TADF OLEDs.
Assoc.Prof. Zawawi Bin Daud
Faculty of Civil & Environmental Engineering, Universiti Tun Hussein Onn Malaysia
Title: Landfill Leachate Treatment Using Combined Adsorbents
Abstarct: Landfills generate leachate having both organic and inorganic pollutants at elevated concentrations is unsafe to human health and the ecosystem if discharged without treatment. The method for the remediation of leachate using conventional adsorbent require extensive resources compared to the method of adsorption by non-conventional materials. Thus, the aim of this research was to prepare adsorbent from native natural materials for the treatment of Chemical Oxygen Demand (COD) and Ammoniacal Nitrogen (NH3-N) using the optimum parameter obtained in a batch adsorption study. Sample leachate was collected from the landfill and characterized. Adsorbent media were procured, cleaned and ground to granular particle sizes for the analysis. All analyses were according to standard methods using analytical grade chemicals. Application of feldspar (FD) and cockle shell (CS) adsorbent as a part replacement material for activated carbon (AC) and zeolite (ZE) in the removal of COD and NH3-N from a stabilized leachate. The contact angle characterization of the FD, ZE, AC and CS was obtained using pendant drop contact angle experiment.
Assoc.Prof. Peng Liu
Huazhong University of Science and Technology
Research area: Heterogeneous catalysis
Title: Replacing thermocatalytic oxidative coupling of alkynes by visible light-driven photocatalytic reaction
Abstarct: The development of green and energy-efficient photocatalytic chemical transformations is one of the most promising strategies to relieve the environmental and energy crisis. Copper-based mixed oxide catalysts have shown promise for thermocatalytic oxidative homocoupling of alkynes (OHA) to 1,3-diynes, but most of them are effective only in the presence of nitrogen-containing ligands or base additives, which usually bring corrosion and pollution problem. To meet the requirements of green and sustainable production of 1,3-diyne for practical application, we proposed a novel strategy on visible light-driven photocatalytic OHA over supported copper nanoparticles (CuNPs) by using the localized surface plasmon resonance (LSPR) effect of CuNPs. Among various supported CuNPs, we found that prereduced copper ferrite (CuFe2O4) can be used as efficient heterogeneous catalysts for the photocatalytic OHA. For the first time, we clarified that surface Cu+ species is the active site for the thermocatalytic OHA, whereas metallic CuNPs are the active species for the photocatalysis. The LSPR effect of CuNPs enables photocatalytic OHA at ambient temperature. The efficiency of photocatalytic OHA is comparable to that of thermocatalytic OHA using various aromatic alkynes at 120 oC, and the optimal Cu/CuFe2O4 catalyst can be magnetically separated and reused at least five times.