Review
Materials Science, Ceramics
Vitaly Gurylev, Tsong Pyng Perng
Summary: Defects in zinc oxide (ZnO) play a crucial role in influencing its properties and applications, with potential for improved characteristics through the introduction of oxygen and zinc vacancies. Defective ZnO shows broad application potential in nanoscale devices, yet faces challenges and requires further research for in-depth exploration.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Engineering, Environmental
Ying Wang, Haitao Yu, Debao Wang, Miaomiao Xing, Yanan Zhang, Caixia Song
Summary: The traditional photocatalytic hydrogen evolution pathway has limited reaction efficiency. In this study, a novel low-energy barrier route is proposed by regulating the active sites, leading to efficient hydrogen generation. The experimental results demonstrate a significant improvement in the photocatalytic hydrogen evolution efficiency of the catalyst.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Nanoscience & Nanotechnology
Jun-Ho Byun, Woon-San Ko, Ki-Nam Kim, Do-Yeon Lee, So-Yeon Kwon, Hi-Deok Lee, Ga-Won Lee
Summary: In this study, ZnO nanoparticles are suggested to enhance performance and reduce variation in device switching parameters in resistive random-access memory (ReRAM) devices. The formation of ZnO nanoparticles is verified using transmission electron microscopy, x-ray diffraction pattern, and atomic force microscopy after annealing ZnO prepared via atomic layer deposition on HfO2. The diffusing of oxygen from HfO2 to ZnO nanoparticles during annealing is explained by the calculation results using density functional theory (DFT).
Article
Engineering, Electrical & Electronic
Hsing- Hsiang, Chih-Cheng Chen, Chia-Chin Kao
Summary: This study investigated the effects of additives and cooling rate on the densification, microstructure, and varistor performance of ZnO-Co3O4-Mn3O4 varistors. Adding ZnBi2O4 promoted densification and lowered the sintering temperature. Slow cooling rate improved the alpha value. Adding ZnBi2O4 facilitated electron transfer and oxygen reaction, resulting in a higher Schottky barrier and alpha value.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Energy & Fuels
Hao Chen, Haishuai Cui, Yang Lv, Pingle Liu, Fang Hao, Wei Xiong, He'an Luo
Summary: Cu/ZnO/ZrO2 catalysts with different ZnO morphologies were prepared and used for CO2 hydrogenation to methanol. The catalyst with flower-like ZnO morphology showed the highest catalytic performance and possess the most oxygen vacancies. The experimental results and DFT calculations suggest that oxygen vacancies play a crucial role in promoting the reaction and reducing the energy barriers.
Article
Chemistry, Physical
Yongjun Fu, Zhichen Wang, Shaoqiang You, Rongbin Zhang, Xuewen Wang
Summary: Surface defect engineering strategies play a critical role in catalytic activity, especially in the photodegradation of organic pollutants. The function of oxygen vacancies in the photooxidation performance of ZnO is still unclear. This research presents a new idea for the surface defect engineering design of regulated photocatalysts to enhance photocatalytic activity.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Yichang Lin, Sheng Liu
Summary: Engineering oxygen vacancies in metal oxides can improve their photoelectrochemical performances. A ZnO nanowire photoanode with oxygen vacancies demonstrated superior photocathodic protection performance, with the protection potential stabilizing at a high level under continuous illumination.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Xiaoyan Fu, Jiayi Li, Jun Long, Chenxi Guo, Jianping Xiao
Summary: This study systematically investigates the activity and selectivity of syngas conversion over zinc oxide (ZnO) catalyst through graph theory and density functional theory. It reveals that the evolution of ZnO surfaces plays a crucial role in product selectivity, with low oxygen vacancy concentration favoring methanol production.
Article
Chemistry, Applied
Haihua He, Ding Hua, Junhua Ren, Zhenxiang Liu, Chonglai Chen, Jiajia Liu, Weiyun Yang
Summary: By tuning the Co loading, we prepared CoxFe1-xFeAlO4-8 spinel with engineered oxygen vacancies and investigated its performance for hydrogen production through chemical looping. The Co0.4Fe0.6FeAlO4-8 exhibited a stable trend with a high hydrogen yield of 10.56 mmol.g 1 for 100 cycles at 600 degrees C. The doping effect of Co decreased the energy barriers for oxygen vacancy formation, resulting in a high oxygen vacancy concentration on the surface. The enhanced oxygen diffusion improved the chemical looping hydrogen production performance of the material.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Chemistry, Physical
Alireza Ranjbari, Kristof Demeestere, Ki-Hyun Kim, Philippe M. Heynderickx
Summary: The effect of temperature-programmed H2 reduction on modification of surface oxygen vacancies in commercial ZnO (C-ZnO) was investigated. The photocatalytic degradation of the fungicide thiabendazole was optimized by treating C-ZnO with 10% H2/Ar gas at 500 degrees C over 5 h. The formation of oxygen vacancies and their catalytic activity were compared before and after the reduction treatment based on their characterization analysis (e.g., TPR, FE-SEM, EDS, XPS, Tauc plot, XRD, and BET). Our most recent kinetic modeling was carried out on the experiments using C-ZnO and T500 at different pH values. The highest adsorption removal and photocatalytic degradation rate (and quantum yield) occurred at pH 3 and 11, respectively. Good reusability of the optimal reduced catalyst was confirmed when tested over five cycles. A strong compatibility between the kinetic modeling results and all characterization analyses supports the potent role of reduction treatment for the modification of oxygen vacancies on photocatalysis.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Hongyu Ma, Kewei Liu, Zhen Cheng, Zhiyao Zheng, Yinzhe Liu, Peixuan Zhang, Xing Chen, Deming Liu, Lei Liu, Dezhen Shen
Summary: The study focuses on the response speed and dark current issues of ZnO quantum dots photodetector, demonstrating improved performance by adjusting reaction conditions. The device shows excellent performance under UV light illumination, providing insights for the design of high-performance photodetectors based on ZnO QDs.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Applied
Chih-Ming Lin, Yu-Chin Tseng, Yi-Jia Tsai, Yu-Sheng Lin, Sheng-Rui Jian, Yu-Chun Chuang, Jenh-Yih Juang
Summary: In situ angle-dispersive X-ray diffraction study revealed that transition metal doping can significantly reduce the onset pressure of ZnO's pressure-driven phase transition from fourfold to sixfold structure. The transition path is influenced by the specific transition metal element. The doping-induced lattice distortion and the amount of 3d electrons carried by the transition metal atom both play important roles in the mechanism of the phase transition.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Analytical
Yiju Song, Xiaoning Meng, Mingshu Bi, Wei Gao
Summary: A strategy was used to construct a hydroxyl-oxygen vacancy model by functionalizing palladium nanoparticles (Pd NPs) on cubic, rod and spherical CeO2, through a simple reduction process to obtain the Ce4+/Ce3+ transited and the generated of Pd. The 5.0 wt% Pd NPs /CeO2-C sensor showed sensitive H2 sensing performance and fast sensing speed at 25 degrees C, with a detection limit of 50 ppm.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Energy & Fuels
Cafer Saka
Summary: In this study, g-C3N4 was applied to H-2 production for the first time in the field of NaBH4 methanolysis, with O doped g-C3N4 showing a significant increase in H-2 production with an HGR value of 10800 ml min g(-1). The activation energy for O doped g-C3N4 was approximately 36.13 kJ mol(-1).
Article
Chemistry, Physical
Bhagyashree Priyadarshini Mishra, Lopamudra Acharya, Satyabrata Subudhi, Kulamani Parida
Summary: In this study, a 1D-2D junction based photocatalyst with abundant oxygen vacancies and dual oxidation states of Mn was prepared. The synthesized photocatalyst exhibited excellent photocatalytic activity for water oxidation and reduction reactions. The results provide valuable insights for the design of efficient photocatalysts.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)