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431. Spatiotemporal active phase evolution for CO2electrocatalysis

Author

Kim, Juwon, Lee, Si Young, Kim, Se-Jun, Koo, Bonho, Chung, Jinkyu, Lee, Danwon, Choi, Subin, Kim, Jimin, Seo, Sungjae, Nam, Chihyun, Gandionco, Karl Adrian, Bak, Gwangsu, Jo, Sugeun, Kim, Namdong, Shin, Hyun-Joon, Chae, Keun Hwa, Won, Da Hye, Marcus, Matthew A., Shapiro, David A., Haw, Shu-Chih, Alsem, Daan Hein, Salmon, Norman J., Min, Byoung Koun, Kim, Hyungjun, Hwang, Yun Jeong, and Lim, Jongwoo

Abstract

Revealing and redirecting the dynamic evolution of active species in efficient electrochemical CO2reduction (ECR) catalysts is challenging. By observing the chemical and morphological evolution in highly efficient ECR catalysts at the nanoscale via operandosoft X-ray microscopy, we identified the dynamic transformation of cationic Cu species during operation. The surface Cu2+phases, observed during a dynamic phase transformation of Cu(OH)2, additionally boost C–C coupling activity beyond the capability of metallic Cu phases. We suggest that copper(II)-carbonate-hydroxide species could dynamically persist under a cathodic environment. By observing the Cu+phase during the phase transformation and the formation of surface Cu2+species, we were able to electrochemically redirect low-active catalysts into high-active catalysts for C–C coupling. Density functional theory calculations also support that Cu2+species could contribute to C–C coupling activity enhancement via ∗CO adsorption energy modulation.

Published
2024
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432. Hole-selective-molecule doping improves the layer thickness tolerance of PEDOT:PSS for efficient organic solar cells

Author

Zhao, Bin, Huang, Xiaozhen, Chung, Sein, Zhang, Min, Zhong, Yufei, Liang, Anhai, Zhao, Zhenmin, Zhu, Chaofeng, Zhao, Jingjing, Kim, Seunghyun, Kim, Jimin, Wang, Ming, Chen, Shilin, Cho, Kilwon, Wang, Yang, and Kan, Zhipeng

Abstract

When used in organic solar cells, poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) aligns interfacial energy levels, promotes hole extraction, blocks electrons, and optimizes the active layer’s morphology. However, with an optimal thickness of approximately 30–40 ​nm, PEDOT:PSS has insufficient layer thickness tolerance, owing to its low conductivity and hole extraction property. Herein, a hole-selective-molecule doping strategy is proposed to enhance the properties of PEDOT:PSS by introducing MPA2FPh-BT-BA (abbreviated as 2F) into its layer. 2F assembles at the anode to form interfacial dipoles due to its unique donor–acceptor–anchor molecular configuration, altering the anode work function and hole-selective extraction. Additionally, 2F improves the aggregation properties of PEDOT:PSS by forming hydrogen bonds with the PSS group, enhancing the conductivity characteristics. These changes in the PEDOT:PSS layer further influence the overlaying morphology, leading to increased crystalline features of PM6 and the bulk heterojunction of PM6:Y6. When a 2F-PEDOT:PSS (2FPP) layer is used, power conversion efficiencies of 18.3%, 19.2%, and 19.1% are achieved in PM6:Y6, PM6:BTP-eC9, and PM6:L8-BO devices, respectively, outperforming counterparts with PEDOT:PSS. Specifically, the performance of PM6:Y6 devices with a 2FPP layer of 170 ​nm remains at > 15%, providing valuable guidance for designing a thickness-insensitive hole transport layer for high-efficiency organic solar cells.

Published
2024
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433. Market growth strategies for sustainable smart farm: A correlation and causal relationship approach

Author

Jung, Mincheol, Kim, Jimin, Kim, Handon, Hong, Taehoon, and Jang, Hyounseung

Abstract

Smart farms are integral to agriculture, evolving with technology while increasing energy consumption. Addressing issues like data scarcity is vital for smart farm-market growth. This study identified these issues and conducted an analysis of both correlation and causal relationship. Additionally, it created a growth strategy roadmap for the smart farm-market, tailored to stakeholders. To achieve carbon neutrality, government support, energy self-sufficiency tech, and energy reduction efforts are essential. These findings offer valuable guidance for policy formulation and operational planning, aiding the promotion of smart farm-market growth with sustainability in mind. In summary, smart farms are evolving alongside technology but face energy challenges, data issues, and the need for supportive policies and sustainable practices, all of which this study addresses to foster growth.

Published
2023
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434. Analyzing the impact of indoor environmental quality on physiological responses and work performance: Implications for IEQ control strategies.

Author

Oh, Donggeun, Kim, Jimin, Kim, Handon, Jang, Hyounseung, Hong, Taehoon, and An, Jongbaek

Abstract

This study aims to analyze the effects of indoor environmental quality (IEQ) factors with simultaneous changes in illuminance and noise levels on building occupants' physiological response and work performance. To this end, four scenarios with changes in illuminance and noise levels were set up, and brain wave indices and work performance measured through a Stroop test were conducted during the scenarios. First, the findings revealed that noise and the interaction between illuminance and noise affect the building occupants' physiological response. Second, the illuminance was 150 lux, and the noise level was 40 dB, there was a correlation between the relative theta (0.685; p <.05) at the F3 location on the scalp and the average reaction time. Lastly, a comparison was made between psychologically preferred IEQ, IEQ when the physiological response is excellent, and IEQ when work performance is excellent. IEQ when the physiological response is excellent showed a high correlation with psychologically preferred IEQ, and it had a higher correlation with IEQ when work performance is excellent than psychologically preferred IEQ. Hence, an IEQ control strategy based on the physiological responses is necessary to improve work performance. It is expected to enhance building occupants' work performance, health, and comfort. • Four scenarios were constructed according to changes in illuminance and noise. • Interaction of the light and sound environment affects the occupants' physiological response. • Relative theta monitoring allows early detection of work performance degradation. • It can be expanded to an interface that optimizes indoor environment. • The results can be used to build an IEQ control data model to boost work performance. [ABSTRACT FROM AUTHOR]

Published
2023
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442. Enhanced biglycan gene expression in the adipose tissues of obese women and its association with obesity-related genes and metabolic parameters

Author

Kim, Jimin, primary, Lee, Seul Ki, additional, Shin, Ji-min, additional, Jeoun, Un-woo, additional, Jang, Yeon Jin, additional, Park, Hye Soon, additional, Kim, Jong-Hyeok, additional, Gong, Gyung-Yub, additional, Lee, Taik Jong, additional, Hong, Joon Pio, additional, Lee, Yeon Ji, additional, and Heo, Yoon-Suk, additional

Published
2016
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448. Cover Picture: Copper-Catalyzed Double Decarboxylative Coupling Reactions of Alkynyl Carboxylic Acid and Glyoxylic Acid: Synthesis of Propargyl Amines and Imidazopyridines (Asian J. Org. Chem. 6/2016)

Author

Choi, Jinseop, primary, Lim, Jeongah, additional, Irudayanathan, Francis Mariaraj, additional, Kim, Han-Sung, additional, Park, Jaerim, additional, Yu, Su Been, additional, Jang, Yuna, additional, Raja, Gabriel Charles Edwin, additional, Nam, Kye Chun, additional, Kim, Jimin, additional, and Lee, Sunwoo, additional

Published
2016
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