Lee, S-W, Abdi ZG, Chen J-C, Chen K-H.
2021.
Optimal method for preparing sulfonated polyaryletherketones with high ion exchange capacity by acid-catalyzed crosslinking for proton exchange membrane fuel cells, 2021. Journal of Polymer ScienceJournal of Polymer Science. 59(8):706-720.: John Wiley & Sons, Ltd
AbstractAbstract Sulfonated polyaryletherketones (SPAEK) bearing four sulfonic acid groups on the phenyl side groups were synthesized. The benzophenone moiety of polymer backbone was further reduced to benzydrol group with sodium borohydride. The membranes were crosslinked by acid-catalyzed Friedel-Crafts reaction without sacrifice of sulfonic acid groups and ion exchange capacity (IEC) values. Crosslinked membranes with the same IEC value but different water uptake could be prepared. The optimal crosslinking condition was investigated to achieve lower water uptake, better chemical stability (Fenton's test), and higher proton conductivity. In addition, the hydrophilic ionic channels from originally course and disordered could be modified to be narrow and continuous by this crosslinking method. The crosslinked membranes, CS4PH-40-PEKOH (IEC = 2.4 meq./g), reduced water uptake from 200 to 88% and the weight loss was reduced from 11 to 5% during the Fenton test compared to uncrosslinked one (S4PH-40-PEK). The membrane showed comparable proton conductivity (0.01?0.19?S/cm) to Nafion 212 at 80°C from low to high relative humidity (RH). Single H2/O2 fuel cell based on the crosslinked SPAEK with catalyst loading of 0.25?mg/cm2 (Pd/C) exhibited a peak power density of 220.3 mW/cm2, which was close to that of Nafion 212 (214.0 mW/cm2) at 80°C under 53% RH. These membranes provide a good option as proton exchange membrane with high ion exchange capacity for fuel cells.
Wei, PC, Chattopadhyay S, Lin FS, Hsu CM, Jou S, Chen JT, Huang PJ, Chen LC, Chen KH, Shih HC.
2009.
Origin of the anomalous temperature evolution of photoluminescence peak energy in degenerate InN nanocolumns. Opt. Express. 17:11690-11697.
Hammad Elsayed, M, Abdellah M, Alhakemy AZ, Mekhemer IMA, Aboubakr AEA, Chen B-H, Sabbah A, Lin K-H, Chiu W-S, Lin S-J, Chu C-Y, Lu C-H, Yang S-D, Mohamed MG, Kuo S-W, Hung C-H, Chen L-C, Chen K-H, Chou H-H.
2024.
Overcoming small-bandgap charge recombination in visible and NIR-light-driven hydrogen evolution by engineering the polymer photocatalyst structure, 2024. Nature Communications. 15(1):707.
AbstractDesigning an organic polymer photocatalyst for efficient hydrogen evolution with visible and near-infrared (NIR) light activity is still a major challenge. Unlike the common behavior of gradually increasing the charge recombination while shrinking the bandgap, we present here a series of polymer nanoparticles (Pdots) based on ITIC and BTIC units with different π-linkers between the acceptor-donor-acceptor (A-D-A) repeated moieties of the polymer. These polymers act as an efficient single polymer photocatalyst for H2 evolution under both visible and NIR light, without combining or hybridizing with other materials. Importantly, the difluorothiophene (ThF) π-linker facilitates the charge transfer between acceptors of different repeated moieties (A-D-A-(π-Linker)-A-D-A), leading to the enhancement of charge separation between D and A. As a result, the PITIC-ThF Pdots exhibit superior hydrogen evolution rates of 279 µmol/h and 20.5 µmol/h with visible (>420 nm) and NIR (>780 nm) light irradiation, respectively. Furthermore, PITIC-ThF Pdots exhibit a promising apparent quantum yield (AQY) at 700 nm (4.76%).