Review
Chemistry, Physical
Xuecheng Yan, Yi Jia, Xiangdong Yao
Summary: This article focuses on the manipulation of electronic structures and surface properties of electrocatalysts, as well as the introduction of defects to enhance their activity. It summarizes the commonly used methods for creating anion and cation vacancies, and emphasizes the control of defect density and filling heteroatoms to improve catalytic performance.
Article
Nanoscience & Nanotechnology
Esmaeil Zaminpayma, Payman Nayebi, Mohsen Emami-Razavi
Summary: The transport properties and rectification behavior of junctions containing armchair graphene nanoribbons with double vacancy defects or nitrogen doping in three different sizes were studied. Results showed that the presence of double vacancy defects and nitrogen doping can alter the behavior of the devices, with significant rectification observed in the 9-atom size devices.
Article
Multidisciplinary Sciences
Zhangliu Tian, Cheng Han, Yao Zhao, Wenrui Dai, Xu Lian, Yanan Wang, Yue Zheng, Yi Shi, Xuan Pan, Zhichao Huang, Hexing Li, Wei Chen
Summary: The photocatalytic generation of hydrogen peroxide (H2O2) using benzylamine oxidation as a half-reaction coupled with ZrS3 nanobelts shows excellent efficiency and selectivity in the simultaneous oxidation of benzylamine to benzonitrile.
NATURE COMMUNICATIONS
(2021)
Article
Polymer Science
Cheng Qian, Yunlong Li, Jing Zhao, Shijie Wang
Summary: Molecular dynamics (MD) simulations were used to investigate the properties and aging mechanism of three different composites: defect-free carbon nanotubes (CNTs) with antioxidant RD and NBR; single-vacancy (SV)-defective CNTs with antioxidant RD and NBR; and vacancy-adsorbed-atom (VA)-defective CNTs with antioxidant RD and NBR. The results showed that the antioxidant RD had the best protective effect on NBR in the composites, leading to improved mechanical and tribological properties. The presence of SV and VA defects reduced the interfacial interaction of the composites and affected the dispersion and migration of the antioxidant RD.
JOURNAL OF POLYMER RESEARCH
(2023)
Article
Engineering, Environmental
Shaodi Sun, Xiaomin Wu, Zhiwei Huang, Huazheng Shen, Huawang Zhao, Guohua Jing
Summary: In this study, defective two-dimensional (2D) TiO2 nanosheets were synthesized and Pt nanoclusters were successfully anchored through the strong metal-support interaction (SMSI), resulting in excellent activity and stability for room temperature oxidation of formaldehyde.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Julia Bord, Bjoern Kirchhoff, Matthias Baldofski, Christoph Jung, Timo Jacob
Summary: Density functional theory (DFT) is utilized to investigate the electronic structure of platinum clusters on different graphene substrates. The size and defects of both the clusters and the graphene substrates are examined. The results reveal that larger vacancies lead to stronger binding of Pt clusters, while defect-free graphene shows more exothermic formation energy with increasing cluster size. Oxygen-free graphene supports are crucial for successful attachment of Pt, and cluster stability depends on the number and ratio of Pt-C, Pt-Pt, and Pt-O bonds rather than the cluster geometry.
Article
Engineering, Environmental
Wei-Fan Kuan, Wen-Yueh Yu, Fang-Yi Tu, Ching-Hsiu Chung, Yu-Cian Chang, Monica Mengdie Lin, Tzu-Hsien Yu, Li-Jen Chen
Summary: A facile reflux process has been developed to synthesize ceria nanorods in a mild environment, enriching the surface with abundant trivalent Ce ions and oxygen vacancy sites, significantly enhancing its catalytic activity in synthesizing dimethyl carbonate. The reflux-synthesized ceria nanorods exhibit over 3 times higher DMC yield than hydrothermal counterpart due to their superior CO2 adsorption and activation capabilities. This study presents a practical strategy to synthesize CeO2 catalysts with exceptional catalytic activity by creating a defective mesoporous surface structure in a highly-efficient manner.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Cheng-May Fung, Boon-Junn Ng, Chen-Chen Er, Wei-Kean Chong, Jingxiang Low, Xuecheng Guo, Xin Ying Kong, Hing Wah Lee, Lling-Lling Tan, Abdul Rahman Mohamed, Siang-Piao Chai
Summary: A homo-hetero architecture consisting of oxygen-defective ultrathin BiVO4 (BiVO4-Ov) and red/black phosphorus (RP/BP) homojunction with a built-in nanoscale dual Z-scheme electronic configuration is developed to address the sluggish charge kinetics and rapid carrier recombination in CO2 photoreduction. The BiVO4-Ov@RP/BP system demonstrates a remarkably high CH4 yield after 6 h of visible light illumination, resembling a leading-edge photocatalytic performance among the existing semiconductors.
Article
Chemistry, Physical
Cheng-Zong Yuan, Shuo Wang, Kwan San Hui, Kaixi Wang, Junfeng Li, Haixing Gao, Chenyang Zha, Xiaomeng Zhang, Duc Anh Dinh, Xi-Lin Wu, Zikang Tang, Jiawei Wan, Zongping Shao, Kwun Nam Hui
Summary: The synergistic regulation of electronic structures of transition-metal oxide-based catalysts using oxygen vacancy defects and single atom doping can significantly enhance their performance in oxygen evolution reaction (OER). In this study, a simple defect-induced in situ single-atom deposition strategy was developed to deposit atomically dispersed Ru single atoms onto oxygen vacancy-rich cobalt oxides (Ru/Co3O4-x) by a spontaneous redox reaction. The resulting Ru/Co3O4-x electrocatalyst, with the coexistence of oxygen vacancies and Ru atoms, exhibited excellent OER performance with a low overpotential, small Tafel slope value, and good long-term stability in alkaline media. Density functional theory calculations revealed that the synergy between oxygen vacancies and atomically dispersed Ru can optimize the adsorption of oxygen-based intermediates and reduce the reaction barriers of OER by tailoring the electron decentralization and d-band center of Co atoms. This study proposes a feasible strategy for constructing electrocatalysts with abundant oxygen vacancies and atomically dispersed noble metals, and provides a deep understanding of the electronic engineering of transition-metal-based catalysts to boost OER.
Article
Materials Science, Composites
Wei Zhang, Renjie Zhang, Yanli Tan, Yun Xue, Jidong Dong, Lina Ma, Zaixing Jiang, Yudong Huang
Summary: By utilizing a simple method, micro/mesoporous S-NiCo2O4/AC hybrids with abundant vacancy defects were designed, exhibiting superior structural durability, good electrical conductivity, and rich active sites, leading to excellent energy density and power density.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Chemistry, Physical
Cheng-Zong Yuan, Shuo Wang, Kwan San Hui, Kaixi Wang, Junfeng Li, Haixing Gao, Chenyang Zha, Xiaomeng Zhang, Duc Anh Dinh, Xi-Lin Wu, Zikang Tang, Jiawei Wan, Zongping Shao, Kwun Nam Hui
Summary: The synergistic regulation of the electronic structures of transition-metal oxide-based catalysts via oxygen vacancy defects and single-atom doping is efficient to boost their oxygen evolution reaction (OER) performance. In this study, a facile defect-induced in situ single-atom deposition strategy is developed to anchor atomically dispersed Ru single-atom onto oxygen vacancy-rich cobalt oxides (Ru/Co3O4-x) based on the spontaneous redox reaction between Ru3+ ions and nonstoichiometric Co3O4-x. The as-prepared Ru/Co3O4-x electrocatalyst with the coexistence of oxygen vacancies and Ru atoms exhibits excellent performances toward OER.
Article
Chemistry, Multidisciplinary
Chengguang Lang, Wenbin Jiang, Cheng-Jie Yang, Hao Zhong, Peirong Chen, Qilong Wu, Xuecheng Yan, Chung-Li Dong, Yue Lin, Liuzhang Ouyang, Yi Jia, Xiangdong Yao
Summary: A facile and eco-friendly method of high-energy mechanochemical ball milling is developed to prepare Ru-1@D-MoS2 catalysts, which exhibit superb alkaline hydrogen evolution enhancement. The single atomic Ru doping induces the generation of S vacancies, leading to an asymmetrical distribution of electrons, which contributes to the excellent performance of Ru-1@D-MoS2.
Article
Materials Science, Multidisciplinary
S. Ajori, A. R. Eftekharfar
Summary: Classical molecular dynamics simulations were used to investigate the mechanical properties of defective penta-graphene under uniaxial tension. The results showed that defects can tune the Young's modulus and Poisson's ratio, and the material exhibited weak anisotropic behavior.
DIAMOND AND RELATED MATERIALS
(2022)
Article
Engineering, Environmental
Jinbao Wang, Yanchao Qin, Longhui Li, Shuo Zhang, Xiangdong Pei, Zhulin Niu, Xiu-Cheng Zheng, Dan Li
Summary: Carbon-based materials have become a popular research topic for potassium ion anode materials due to their unparalleled advantages of being environmentally friendly and low-cost. Recent studies have shown that N, O-doping can improve ion transfer and provide abundant active sites. Density functional theory calculations confirm that N, O-doping and vacancy defects increase the adsorbability of potassium ions. Additionally, vacancy defects and heteroatom doping induce the spontaneous migration of potassium ions. Inspired by these findings, nanobowl-like carbon structures with abundant vacancy defects and N, O heteroatoms are designed, resulting in high-capacity and long-life N, O-doped carbon nanobowls.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Electrochemistry
Caini Tan, Rui Ding, Yongfa Huang, Tong Yan, Yuxi Huang, Feng Yang, Xiujuan Sun, Ping Gao, Enhui Liu
Summary: Na-based dual-ion batteries (Na-DIBs) and capacitors (NICs) have gained attention due to their simple design, environmentally friendly nature, feasibility, and low cost. In this study, a new vacancy defective perovskite fluorides K0.82Co0.43Mn0.57F2.66@reduced graphene oxide (KCMF(1-1)@rGO) nanocrystal was introduced as a promising anode material for Na-DIBs and NICs, showcasing superior specific capacity, rate, and cycling behavior. The designed Na-DIBs and NICs with the KCMF(1-1)@rGO anode exhibited remarkable performance, indicating a promising application for Na-ion energy storage.
ELECTROCHIMICA ACTA
(2021)
Article
Thermodynamics
Pei-Hsing Huang, Jenn-Kun Kuo, Sie-Jhih Tsai, Yu-Chou Tsai
APPLIED THERMAL ENGINEERING
(2018)
Article
Automation & Control Systems
Jenn-Kun Kuo, Pei-Hsing Huang, Hsin-Yi Lai, Wei-Jen Wu
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2019)
Article
Chemistry, Physical
Jenn-Kun Kuo, Hsin-Yi Lai, Pei-Hsing Huang, Jhih-Wei Jhan
MOLECULAR SIMULATION
(2018)
Article
Chemistry, Physical
Jenn-Kun Kuo, Jian-Yao Huang
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2019)
Article
Thermodynamics
Pei-Hsing Huang, Jenn-Kun Kuo, Wei-Chun Tu
COMBUSTION SCIENCE AND TECHNOLOGY
(2020)
Article
Energy & Fuels
Jenn-Kun Kuo, Hou-Chung Wei
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2019)
Article
Materials Science, Multidisciplinary
Pei-Hsing Huang, Shao-Yu Chien, Ping Wu, Chuen-Shii Chou
MATERIALS & DESIGN
(2020)
Article
Chemistry, Physical
Pei-Hsing Huang, Jenn-Kun Kuo, Wei-Zhe Jiang, Cheng-Bi Wu
Summary: This study simulated a proton-electrolyte membrane fuel cell (PEMFC) system using MATLAB and Simulink to analyze the efficiency of combined heat and power (CHP) systems. Factors such as hydrogen recirculation rate and pressure were considered to elucidate the mechanism of hydrogen circulation, leading to methods for improving fuel cell efficiency under certain conditions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Biochemistry & Molecular Biology
Jenn-Kun Kuo, Yu-Ting Tsai, Pei-Hsing Huang, Jheng-Yu Luo
Summary: This study employed molecular dynamics to simulate the dynamic adsorption behavior of acidic fluid molecules in gold nanoslits, finding that Au(110) has optimal capture capabilities for H2O and H2S. The design of array structures with slit widths 8.15x5.76 angstrom resulted in the highest average adsorption energy and static adsorption amount, increasing the self-diffusion coefficient of gas molecules and providing stable adsorption sites.
JOURNAL OF MOLECULAR MODELING
(2021)
Article
Chemistry, Physical
Pei-Hsing Huang, Jenn-Kun Kuo, Shang-Shu Chung
Summary: This study analyzes the numerical analysis of membrane electrode assembly in Proton Exchange Membrane Fuel Cell (PEMFC) and discusses the effects of parameters such as permeability, porosity, and oper-ation voltage on various fractions, curves, and efficiency. The results show that high gas permeability is an important factor affecting the hydrogen fraction. Increasing porosity can improve fuel cell performance, but it may also negatively impact electrical conductivity and increase water flooding, reducing efficiency.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Automation & Control Systems
Jenn-Kun Kuo, Jun-Jia Wu, Pei-Hsing Huang, Chin-Yi Cheng
Summary: This study successfully applied automated optical inspection (AOI) combined with convolutional neural networks (CNNs) to detect sandblasting defects in investment castings, reducing labor costs and improving employee health and safety. Among the four classic CNN models tested, AlexNet and VGG-16 showed the highest accuracy in defect detection, with a prediction accuracy of 100% for defective products.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Chemistry, Physical
Wei-Hsin Chen, Kuan-Hsiang Chen, Jenn-Kun Kuo, Ayyadurai Saravanakumar, Kit Wayne Chew
Summary: This study utilizes a palladium membrane to separate hydrogen from an H2/CO2 gas mixture and investigates the effects of temperature, total pressure difference, and vacuum degree on hydrogen permeation. The results demonstrate that vacuum degree has the most significant impact on H2 flux, while total pressure difference has the most influence on CO2 transport. The response surface methodology provides accurate predictions in comparison with experimental results.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Pei-Hsing Huang, Jenn-Kun Kuo, Cheng-Bi Wu
Summary: Simulations and experiments were conducted to evaluate the performance of a vacuum ejector in a PEMFC system. The results showed that the recirculation ratio and hydrogen stoichiometric ratio increased with decreasing primary flow pressure and secondary flow temperature. The prototype vacuum ejector demonstrated a maximum gas leakage of 0.7 psi and a minimum hydrogen recirculation rate of 59.3%, indicating its potential for passive hydrogen recovery in large-scale fuel cell systems.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)