Jarwal, B, Abbas S, Chou T-L, Vailyaveettil SM, Kumar A, Quadir S, Ho T-T, Wong DP, Chen L-C, Chen K-H.
2024.
Boosting Thermoelectric Performance in Nanocrystalline Ternary Skutterudite Thin Films through Metallic CoTe2 Integration, 2024. ACS Applied Materials & InterfacesACS Applied Materials & Interfaces. 16(12):14770-14780.: American Chemical Society
Abstractn/a
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%).
Syum, Z, Billo T, Sabbah A, kumar Anbalagan A, Quadir S, Hailemariam AG, Sabhapathy P, Lee C-H, Wu H-L, Chen L-C, Chen K-H.
2023.
Enhancing the lithium-ion storage capability of Cu2ZnSnS4 anodes via a nitrogen-doped conductive support, 2023. Chemical Engineering Journal. 465:142786.
AbstractAchieving lithium-ion batteries with both excellent electrochemical performance and cycling stability is a top priority for their real-world applications. This work reports high-performance and stable Cu2ZnSnS4 (CZTS) anode materials encapsulated by nitrogen-doped carbon (CZTS@N-C) for advanced lithium-ion battery application. Ex-situ X-ray photoelectron spectroscopy and transmission electron microscopy revealed that the nitrogen-doped carbon network features a more conducive solid-electrolyte interphase that enables lower charge-transfer resistance and fast Li+ diffusion kinetics with negligible initial irreversible capacity loss. As a result, the CZTS@N-C electrode delivers a significantly enhanced capacity of 710 mAh g−1 with 73% capacity retention after 220 cycles at a current rate of 0.5 mA g−1 and superior rate performance compared to that of unmodified CZTS. Additionally, the study sheds light on the fast lithiation dynamics chemistry of CZTS@N-C through kinetics analysis, explored by in-situ Raman, ex-situ X-ray absorption, and in-situ electrochemical impedance. This study provides a new approach for fabricating high-performance, durable conductive polymer-encapsulated low-cost transition-metal-sulfide anode materials.
Quadir, S, Qorbani M, Sabbah A, Wu T-S, kumar Anbalagan A, Chen W-T, Valiyaveettil SM, Thong H-T, Wang C-W, Cheng-YingChen, Lee C-H, Chen K-H, Chen L-C.
2022.
Short- and Long-Range Cation Disorder in (AgxCu1–x)2ZnSnSe4 Kesterites, 2022. Chemistry of Materials. : American Chemical Society
Abstract
Daichakomphu, N, Abbas S, Chou T-L, Chen L-C, Chen K-H, Sakulkalavek A, Sakdanuphab R.
2022.
Understanding the effect of sputtering pressures on the thermoelectric properties of GeTe films. Journal of Alloys and Compounds. 893:162342.
AbstractIn this work, we study the effect of sputtering pressures on the thermoelectric properties of GeTe films. The working pressures were differentiated from 3 to 30 mTorr, and the as-deposited films were annealed at 623 K for 10 min in Ar atmosphere. The results show that the working pressure has a significant effect on the Ge content and crystalline size. The turning trend of the Seebeck coefficient with different sputtering pressures corresponds to the Ge content. The surface morphology of annealed film will change from cracks to voids with increasing sputtering pressure. This behavior can be explained by the growth mechanisms model. The voids and relatively low crystalline size of GeTe films affect to the reduction of the electrical conductivity. In addition, the void content decreased as film thickness was increased. Therefore, controlling the working pressures in the sputtering process and film thickness is important for the thermoelectric performance of GeTe thin film. In our work, we prove that the thermoelectric properties of GeTe films could be optimized effectively by simply tuning different sputtering conditions.
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.
Samireddi, S, Aishwarya V, Shown I, Muthusamy S, Unni SM, Wong K-T, Chen K-H, Chen L-C.
2021.
Synergistic Dual-Atom Molecular Catalyst Derived from Low-Temperature Pyrolyzed Heterobimetallic Macrocycle-N4 Corrole Complex for Oxygen Reduction. Small. 17:2103823., Number 46
AbstractAbstract A heterobimetallic corrole complex, comprising oxygen reduction reaction (ORR) active non-precious metals Co and Fe with a corrole-N4 center (PhFCC), is successfully synthesized and used to prepare a dual-atom molecular catalyst (DAMC) through subsequent low-temperature pyrolysis. This low-temperature pyrolyzed electrocatalyst exhibited impressive ORR performance, with onset potentials of 0.86 and 0.94 V, and half-wave potentials of 0.75 and 0.85 V, under acidic and basic conditions, respectively. During potential cycling, this DAMC displayed half-wave potential losses of only 25 and 5 mV under acidic and alkaline conditions after 3000 cycles, respectively, demonstrating its excellent stability. Single-cell Nafion-based proton exchange membrane fuel cell performance using this DAMC as the cathode catalyst showed a maximum power density of 225 mW cm−2, almost close to that of most metal–N4 macrocycle-based catalysts. The present study showed that preservation of the defined CoN4 structure along with the cocatalytic Fe–Cx site synergistically acted as a dual ORR active center to boost overall ORR performance. The development of DAMC from a heterobimetallic CoN4-macrocyclic system using low-temperature pyrolysis is also advantageous for practical applications.
Tran Nguyen, NH, Nguyen TH, Liu Y-ren, Aminzare M, Pham ATT, Cho S, Wong DP, Chen K-H, Seetawan T, Pham NK, Ta HKT, Tran VC, Phan TB.
2016.
Thermoelectric Properties of Indium and Gallium Dually Doped ZnO Thin Films, 2016. ACS Applied Materials & InterfacesACS Applied Materials & Interfaces. 8(49):33916-33923.: American Chemical Society
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Han, HC, Tseng CA, Du CY, A.Ganguly, Chong CW, Wang SB, Lin CF, Chang SH, Su CC, Lee JH, Chen KH, Chen LC.
2012.
Enhancing efficiency with fluorinated interlayer in small molecule organic solar cell. J. Mater. Chem.. 22:22899.
Das, CR, Hsu HC, Dhara S, Bhaduri AK, Raj B, Chen LC, Chen KH, Albert SK, Ray A, Tzeng Y.
2010.
A complete Raman mapping of phase transitions in Si under indentation. J. Raman Spectroscopy. 41:334.