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.
Lee, C-P, Chen W-F, Billo T, Lin Y-G, Fu F-Y, Samireddi S, Lee C-H, Hwang J-S, Chen K-H, Chen L-C.
2016.
Beaded stream-like CoSe2 nanoneedle array for efficient hydrogen evolution electrocatalysis, 2016. Journal of Materials Chemistry A. 4(12):4553-4561.: The Royal Society of Chemistry
AbstractThe development of earth-abundant and efficient electrocatalysts for the hydrogen evolution reaction (HER) is one of the keys to success for future green energy systems using hydrogen fuel. Nanostructuring of electrocatalysts is a promising way to enhance their electrocatalytic performance in the HER. In this study, pure pyrite-type beaded stream-like cobalt diselenide (CoSe2) nanoneedles are directly formed on flexible titanium foils through treating a cobalt oxide (Co3O4) nanoneedle array template with selenium vapor. The beaded stream-like CoSe2 nanoneedle electrode can drive the HER at a current density of 20 mA cm−2 with a small overpotential of 125 mV. Moreover, the beaded stream-like CoSe2 nanoneedle electrode remains stable in an acidic electrolyte for 3000 cycles and continuously splits water over a period of 18 hours. The enhanced electrochemical activity is facilitated by the unique three-dimensional hierarchical structure, the highly accessible surface active sites, the improved charge transfer kinetics and the highly attractive force between water and the surface of the nanoneedles that exceeds the surface tension of water.
Lee, CP, Chen* WF, Billo T, Lin YG, Fu FY, Samireddi S, Lee CH, Hwang JS, Chen* LC, Chen* KH.
2016.
Beaded-stream-like CoSe2 nanoneedles array for efficient hydrogen evolution electrocatalysis. J. Mater. Chem. A . 4 :4553-4561.
Lien, H-T, Chang Y-C, Huang C-Y, Hsu H-C, Chang S-T, Wong DP, Wang C-H, Wang C-H, Chen K-H, Chen L-C.
2021.
Solar to hydrocarbon production using metal-free water-soluble bulk heterojunction of conducting polymer nanoparticle and graphene oxide, 2021. The Journal of Chemical PhysicsThe Journal of Chemical Physics. 154(16):164707.: American Institute of Physics
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