ScholarWorks Community:https://scholarworks.bwise.kr/kumoh/handle/2020.sw.kumoh/852024-03-22T15:30:18Z2024-03-22T15:30:18ZToward feasible single atom-based hydrogen evolution electrocatalysts via artificial ensemble sites for anion exchange membrane water electrolyzerLim, Won-GwangTruong, Hoang NamJeong, Jae-YeopKim, DongkyuOh, Lee SeulJo, ChangshinKim, ChihoKim, Hyung JuChoi, Sung MookShin, HyeyoungLee, SeonggyuLim, Eunhohttps://scholarworks.bwise.kr/kumoh/handle/2020.sw.kumoh/264482024-02-28T04:30:38Z2024-04-01T00:00:00ZTitle: Toward feasible single atom-based hydrogen evolution electrocatalysts via artificial ensemble sites for anion exchange membrane water electrolyzer
Authors: Lim, Won-Gwang; Truong, Hoang Nam; Jeong, Jae-Yeop; Kim, Dongkyu; Oh, Lee Seul; Jo, Changshin; Kim, Chiho; Kim, Hyung Ju; Choi, Sung Mook; Shin, Hyeyoung; Lee, Seonggyu; Lim, Eunho
Abstract: Approaching an efficient anion exchange membrane water electrolyzer (AEMWE) with satisfactorily high ki-netics in the alkaline hydrogen evolution reaction (HER) is desired. We design an advanced platinum (Pt) single atom (SA)-based electrocatalyst by incorporating the Ni nanoparticle as an artificial ensemble site adjacent to Pt SA. The designed Pt SA electrocatalyst achieves higher areal current density (500 mA cm-2 at 1.8 V) in the single cell of the AEMWE and better cell voltage stability than the Pt/C electrocatalyst. The Ni nanoparticle assists in separating the binding sites of H* and OH*, in which Ni atoms provide adsorption sites for H*, while OH* adsorbs on the Pt SA. This separation effect drastically accelerates the energy barrier required for the water dissociation reaction in the Volmer step and simultaneously optimizes the H* and OH* binding energy, which extremely enhances the alkaline HER kinetics, thereby demonstrating the feasibility of Pt SA electrocatalysts for AEMWE.2024-04-01T00:00:00ZMetastabilizing the Ruthenium Clusters by Interfacial Oxygen Vacancies for Boosted Water Splitting ElectrocatalysisChen, YaLiu, YaodaZhai, WenfangLiu, HangSakthivel, ThangavelGuo, ShengwuDai, Zhengfeihttps://scholarworks.bwise.kr/kumoh/handle/2020.sw.kumoh/266192024-02-19T01:00:21Z2024-02-01T00:00:00ZTitle: Metastabilizing the Ruthenium Clusters by Interfacial Oxygen Vacancies for Boosted Water Splitting Electrocatalysis
Authors: Chen, Ya; Liu, Yaoda; Zhai, Wenfang; Liu, Hang; Sakthivel, Thangavel; Guo, Shengwu; Dai, Zhengfei
Abstract: Metal-support interaction (MSI) is witnessed as an essential manner to stabilize active metals and tune catalytic activity for heterogonous water splitting. Kinetically driving the water electrolysis (WE) appeals for a rational MSI system with the coupled electron-donating/accepting (e-D/A) characters for hydrogen/oxygen evolution reactions (HER/OER). However, the metal stabilization effect by MSI will in turn restrict the deblocking of e-D/A properties and challenge the full electrocatalytic optimization. This study profiles a heterostructure featuring metastable Ru clusters on defective NiFe hydroxide (Ru/d-NiFe LDH) support as a low-precious (approximate to 2 wt%) catalytic platform for efficient WE. It is indicated that the interfacial oxygen vacancies can deviate the stable Ru 4d5 orbit to a metastable Ru2+delta state, and regulate the metal d-band center levels toward the facilitated HER/OER processes. Resultantly, the Ru/d-NiFe LDH heterostructure attains the ultralow overpotentials at 10 mA cm-2 for Pt-beyond alkaline HER (18 mV) and OER (220 mV) with fast kinetics and durability. The symmetrical water electrolyzer delivers a promising voltage of 1.49 V at 10 mA cm-2 in 1 m KOH and efficient seawater splitting performance. This work carries interesting opportunities in rationalizing sophisticated metal-support electrocatalysts through metal-site metastabilization engineering. A heterostructure featuring metastable Ru clusters on defective NiFe hydroxide (Ru/d-NiFe LDH) support is profiled as a low-precious (approximate to 2 wt%) catalytic platform for efficient Pt/RuO2-beyond water electrolysis. The oxygen vacancies on the NiFe-LDH support are revealed to enhance the interfacial charge transfer at the RuONi bridge, giving rise to metastable Ru2+delta sites deviated from the half-filled 4d5 orbital stable state. image2024-02-01T00:00:00ZFabrication of silicon quantum dots-methyl viologen nanohybrids: Turn-On-Off-On fluorescence nanoprobe for the detection of d-penicillamineRajendran, KalimuthuNabeel, Mattath MohamedPandian, KannaiyanManikandan, VeluGanesan, SivarasanLo, Huang-MuRajendiran, NagappanLiu, XinghuiOluwafemi, Oluwatobi Samuelhttps://scholarworks.bwise.kr/kumoh/handle/2020.sw.kumoh/265982024-02-28T04:30:38Z2024-02-01T00:00:00ZTitle: Fabrication of silicon quantum dots-methyl viologen nanohybrids: Turn-On-Off-On fluorescence nanoprobe for the detection of d-penicillamine
Authors: Rajendran, Kalimuthu; Nabeel, Mattath Mohamed; Pandian, Kannaiyan; Manikandan, Velu; Ganesan, Sivarasan; Lo, Huang-Mu; Rajendiran, Nagappan; Liu, Xinghui; Oluwafemi, Oluwatobi Samuel
Abstract: This study provides a straightforward, one-step hydrothermal approach for synthesizing water-soluble silicon quantum dots (SiQDs). The surface of the synthesized SiQDs is modified by the carboxylic acid functional group (A:SiQDs) after succinic anhydride treatment. The modified A:SiQDs, which emitted blue light fluorescence, showed high stability against photobleaching, thermal stability, and good water solubility. The A:SiQDs are conjugated with methyl viologen (MV2+) to develop a nanohybrid for specific D-Penicillamine (D-PA) detection with an LOD of 8 nM. The suggested sensor was effectively used to analyze D-PA in commercial pharmaceutical formulations using the conventional addition method, and it produced results with good accuracy and precision that were nearly equal to those measured.2024-02-01T00:00:00ZUnveiling the Role of Side Chain for Improving Nonvolatile Characteristics of Conjugated Polymers-Based Artificial SynapseSung, JunhoChung, SeinJang, YongchanJang, HyoikKim, JiyeonLee, ChanLee, DonghwaJeong, DongyeongCho, KilwonKim, Youn SangKang, JoonheeLee, WonhoLee, Eunhohttps://scholarworks.bwise.kr/kumoh/handle/2020.sw.kumoh/285132024-03-13T01:30:30Z2024-02-01T00:00:00ZTitle: Unveiling the Role of Side Chain for Improving Nonvolatile Characteristics of Conjugated Polymers-Based Artificial Synapse
Authors: Sung, Junho; Chung, Sein; Jang, Yongchan; Jang, Hyoik; Kim, Jiyeon; Lee, Chan; Lee, Donghwa; Jeong, Dongyeong; Cho, Kilwon; Kim, Youn Sang; Kang, Joonhee; Lee, Wonho; Lee, Eunho
Abstract: Interest has grown in services that consume a significant amount of energy, such as large language models (LLMs), and research is being conducted worldwide on synaptic devices for neuromorphic hardware. However, various complex processes are problematic for the implementation of synaptic properties. Here, synaptic characteristics are implemented through a novel method, namely side chain control of conjugated polymers. The developed devices exhibit the characteristics of the biological brain, especially spike-timing-dependent plasticity (STDP), high-pass filtering, and long-term potentiation/depression (LTP/D). Moreover, the fabricated synaptic devices show enhanced nonvolatile characteristics, such as long retention time (approximate to 102 s), high ratio of Gmax/Gmin, high linearity, and reliable cyclic endurance (approximate to 103 pulses). This study presents a new pathway for next-generation neuromorphic computing by modulating conjugated polymers with side chain control, thereby achieving high-performance synaptic properties. In organic semiconductors-based neuromorphic devices, it is difficult to endow long-term plasticity in diketopyrrolopyrrole (DPP) polymers due to insufficient interaction with ions. In this article, a rational way is proposed to overcome the deficiency of nonvolatile properties by tailoring the length of the alkyl side-chain of DPP polymers. image2024-02-01T00:00:00Z