Scholar Hub Community:
https://yscholarhub.yonsei.ac.kr/handle/2021.sw.yonsei/4980
2024-03-28T19:23:49ZSolar-to-hydrogen peroxide conversion of photocatalytic carbon dots with anthraquinone: Unveiling the dual role of surface functionalities
https://yscholarhub.yonsei.ac.kr/handle/2021.sw.yonsei/6494
Title: Solar-to-hydrogen peroxide conversion of photocatalytic carbon dots with anthraquinone: Unveiling the dual role of surface functionalities
Authors: Gu Minsu; Lee Do-Yeon; Mun Jinhong; Kim Dongseok; Cho Hae-in; Kim Bupmo; Kim Wooyul; Lee Geunsik; BYEONG-SU KIM; HYOUNG-IL KIM
Abstract: Solar-driven photocatalytic production of hydrogen peroxide (H2O2) requires only sunlight, oxygen, and water, making it a green and sustainable alternative to conventional H2O2 production processes. We present photo-catalytic carbon dots (CDs) as a new candidate for high-performance H2O2 production. Owing to the generation of an excellent charge carrier and the presence of various oxygen-containing functional groups, CDs showed an outstanding H2O2 production capability of 609.4 mu mol g(-1) h(-1) even in the absence of an electron donor, demonstrating promising self-electron-donating capabilities. Hydroxyl groups on their surface, in particular, serve a dual role as photocatalytic active sites and as electron and proton donors toward the oxygen reduction reaction (ORR). The photocatalytic activity of CDs was significantly improved to 1187.8 mu mol g(-1) by functionalizing their surfaces with anthraquinone (AQ) as a co-catalyst; it promoted the charge carrier separation and electrochemically favored the two-electron pathway of ORR. These carbon-based metal-free nanohybrids that are a unique combination of CDs and AQ could offer insights into designing efficient photocatalysts for future solar-to-H2O2 conversion systems.2022-09-01T00:00:00ZSustainable hydrogen peroxide production based on dopamine through Janus-like mechanism transition from chemical to photocatalytic reactions
https://yscholarhub.yonsei.ac.kr/handle/2021.sw.yonsei/6495
Title: Sustainable hydrogen peroxide production based on dopamine through Janus-like mechanism transition from chemical to photocatalytic reactions
Authors: 이도연; 박민주; 김남히; 구민수; HYOUNG-IL KIM; BYEONG-SU KIM
Abstract: With increasing interest in hydrogen peroxide (H2O2) as an environmentally friendly oxidant for environmental remediation and a promising liquid fuel, we present herein a novel method for green and sustainable H2O2 production using versatile dopamine-based materials, demonstrating the conversion of H2O2 generation mechanism from a chemical to a photocatalytic process along with the structural transformation of dopamine to polydopamine. During the auto-oxidation of dopamine in the presence of oxygen, which involved the transition of catechol to hydroquinone groups and the ring closure of the amine group, H2O2 was chemically generated at a rate of 1.61 mmol g-1h?1 without an extra electron donor and additional energy sources. In contrast, self-polymerized polydopamine exhibited an effective photocatalytic H2O2 generation at a rate of 0.53 mmol g-1h?1 owing to its visible light absorptivity and semiconducting property. We anticipate that these unique properties of dopamine will provide a new class of organic-based, highly efficient solar-to-H2O2 conversion and sustainable energy systems in the future.2022-07-01T00:00:00ZStress Dissipation Encoded Silk Fibroin Electrode for the Athlete-Beneficial Silk Bioelectronics
https://yscholarhub.yonsei.ac.kr/handle/2021.sw.yonsei/6291
Title: Stress Dissipation Encoded Silk Fibroin Electrode for the Athlete-Beneficial Silk Bioelectronics
Authors: WOOJIN CHOI; Deokjae Heo; TAEHO KIM; SUNGWONJUNG; MOONHYUN CHOI; JIWOONG HEO; JaeSung Kwon; BYEONG-SU KIM; Wonhwa Lee; Won-Gun Koh; Jeong Ho Cho; Sangmin Lee; JINKEE HONG
Abstract: The kinetic body motions have guided the core-shell fabrics of wearable bioelectronics to be elastoplastic. However, the polymeric electrodes follow the trade-off relationship between toughness and stretchability. To this end, the stress dissipation encoded silk fibroin electrode is proposed as the core electrode of wearable bioelectronics. Significantly, the high degree of intrinsic stress dissipation is realized via an amino acid crosslink. The canonical phenolic amino acid (i.e., tyrosine) of silk fibroin is engineered to bridge the secondary structures. A sufficient crosslink network is constructed when tyrosine is exposed near the amorphous strand. The stress dissipative tyrosine crosslink affords 12.5-fold increments of toughness (4.72 to 58.9 MJ m?3) and implements the elastoplastic silk fibroin. The harmony of elastoplastic core electrodes with shell fabrics enables the wearable bioelectronics to employ mechanical performance (elastoplasticity of 750 MJ m?3) and stable electrical response. The proposed wearable is capable of assisting the effective workouts via triboelectricity. In principle, active mobility with suggested wearables potentially relieves muscular fatigues and severe injuries during daily fitness.2022-03-01T00:00:00ZUniversal Oriented van der Waals Epitaxy of 1D Cyanide Chains on Hexagonal 2D Crystals
https://yscholarhub.yonsei.ac.kr/handle/2021.sw.yonsei/5321
Title: Universal Oriented van der Waals Epitaxy of 1D Cyanide Chains on Hexagonal 2D Crystals
Authors: YANGJINLEE; Koo J.; 이솔; JUN-YEONGYOON; Kim K.; 장명진; JEONGSU JANG; JEONGHEON CHOE; Li B.-W.; Le C.T.; Ullah F.; Kim Y.S.; Hwang J.Y.; Lee W.C.; Ruoff R.S.; Cheong H.; Jinwoo Cheon; Lee H.; KWANPYO KIM
Abstract: The atomic or molecular assembly on 2D materials through the relatively weak van der Waals interaction is quite different from the conventional heteroepitaxy and may result in unique growth behaviors. Here, it is shown that straight 1D cyanide chains display universal epitaxy on hexagonal 2D materials. A universal oriented assembly of cyanide crystals (AgCN, AuCN, and Cu0.5Au0.5CN) is observed, where the chains are aligned along the three zigzag lattice directions of various 2D hexagonal crystals (graphene, h-BN, WS2, MoS2, WSe2, MoSe2, and MoTe2). The potential energy landscape of the hexagonal lattice induces this preferred alignment of 1D chains along the zigzag lattice directions, regardless of the lattice parameter and surface elements as demonstrated by first-principles calculations and parameterized surface potential calculations. Furthermore, the oriented microwires can serve as crystal orientation markers, and stacking-angle-controlled vertical 2D heterostructures are successfully fabricated by using them as markers. The oriented van der Waals epitaxy can be generalized to any hexagonal 2D crystals and will serve as a unique growth process to form crystals with orientations along the zigzag directions by epitaxy.2020-02-01T00:00:00Z