Article
Materials Science, Multidisciplinary
Dongzhu Lu, Quantong Jiang, Xiumin Ma, Kuikui Wang, Xiaole Fu, Yanliang Huang, Baorong Hou
Summary: This study investigated the transport mechanism of Zn cations in a polycrystalline MgO film, finding that despite the presence of various defects, Zn cations can penetrate the entire film. Additionally, while Zn cations move randomly within individual MgO grains, they can move directionally on a macro scale from a constant source to a constant sink located on opposite sides of the film.
MATERIALS CHARACTERIZATION
(2021)
Article
Chemistry, Physical
Fuguang Liu, Zhonghan Feng, Xinyue Zhang, Liang Cui, Jingquan Liu
Summary: Ru@Fe-Ni(OH)2/NF catalyst with excellent activity and stability was prepared using a one-step hydrothermal method.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Huijun Chen, Chaesung Lim, Mengzhen Zhou, Zuyun He, Xiang Sun, Xiaobao Li, Yongjian Ye, Ting Tan, Hui Zhang, Chenghao Yang, Jeong Woo Han, Yan Chen
Summary: This study investigates the impact of B-site cation doping on PSCxFN thin films, revealing that Co doping promotes the formation of oxygen vacancies and enhances surface activity, but excessive Co doping can lead to decreased stability. Moderate levels of Co doping can achieve both good HOR activity and stability.
Article
Chemistry, Applied
Zhong Ma, Junfeng Wang, Guofu Liu, Hui Zhang, Yonggang Lu, Junhui Xiong, Chaoyue Xie, Can Zou
Summary: In this study, alkali metals (potassium, sodium) were used to regenerate deactivated oxygen carriers, with potassium showing rapid regeneration of redox performance and reaching optimal regeneration at a 5% doping ratio. The addition of alkali metals improved gas-solid reactions by forming a porous structure in the deactivated sample, enhancing surface adsorbed oxygen, and increasing oxidation ability. Further increases in potassium content beyond 5% did not significantly affect the regeneration of the deactivated oxygen carriers.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Chemistry, Physical
Xianglan Xu, Li Liu, Yunyan Tong, Xiuzhong Fang, Junwei Xu, De-en Jiang, Xiang Wang
Summary: The introduction of Cr element in the support of Ru/CeO2 catalyst significantly enhanced CO2 methanation activity, primarily by promoting the formate pathway. Cr3+ doping increased the number of surface oxygen vacancies and hydroxyl groups, thereby increasing the production of bicarbonates and formates, leading to improved methane production rates at low temperatures for the Ru/Ce(0.9)Cr(0.1)O(x) catalyst.
Article
Chemistry, Physical
Sergey N. Shkerin, Anna S. Tolkacheva
Summary: Mayenite Ca12Al14O33 +/-delta is an oxide with a complex structure, wide range of oxygen non-stoichiometry, and high deficiency. However, it has inferior conductivity. In this study, doped mayenite was synthesized and its electrical resistance was studied to explore its conductivity. The results are in good agreement with isotope exchange data and illustrate a general trend in transport properties.
Article
Engineering, Environmental
Xiaoli Jiang, Xiaoqiu Yue, Yuanxia Li, Xijun Wei, Qiaoji Zheng, Fengyu Xie, Dunmin Lin, Guoxing Qu
Summary: This research successfully synthesized N/Fe dual-doped nickel phosphides for the first time, showing significant improvement in electronic structure, surface states, and microtopography, leading to enhanced electrocatalytic performance. Computational simulations demonstrated that dual doping can optimize adsorption free energy and improve intrinsic electrocatalytic activity. Consequently, N/Fe-Ni2P/Ni12P5 exhibited outstanding OER performance and long-term durability at high current densities.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Bing Zhang, Jiongwei Shan, Xinying Wang, Yanjie Hu, Yunyong Li
Summary: In this study, Ru/Rh-doped FeOOH nanoarrays with abundant oxygen-vacancies were fabricated on Ti3C2Tx MXene. The optimized electrocatalysts exhibited excellent OER activities and remarkable stabilities. The integration of cation-doping and oxygen-vacancy enhanced the conductivity and lattice defects of FeOOH, improving the specific activity and catalytic kinetics of electrocatalysts.
Article
Chemistry, Analytical
Swarna P. Mantry, Biswaranjan D. Mohapatra, Rajesh K. Behera, Kumar S. K. Varadwaj
Summary: We investigated the electrochemical activity of transition metal ion doped MnOx@N-graphene hybrid catalysts for oxygen reduction reaction (ORR). The doped catalysts showed significantly improved performance compared to the undoped catalyst. The Fe-doped catalyst exhibited the highest positive shift in onset potential, highest electron transfer number, and lowest peroxide yield. The Co-doped catalyst showed the highest current density, comparable to benchmark Pt/C catalyst.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jun Kim, Byeong Jo Min, Taehyun Kwon, Taekyung Kim, Ho Chang Song, Hyung Chul Ham, Hionsuck Baik, Kwangyeol Lee, Jin Young Kim
Summary: This study presents a facile synthetic route to NiCoP nanoparticles with Ru dopants, which exhibit high catalytic performance for the oxygen evolution reaction (OER) in alkaline media with low overpotential and high Tafel slope. The Ru dopants induce a higher content of Ni and Co vacancies in NiCoP nanoparticles, leading to more catalytically active sites and improved electrical conductivity after electrochemical activation.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Engineering, Environmental
Fitri Nur Indah Sari, Hong-Sheng Chen, Aswin Kumar Anbalagan, Yan-Jia Huang, Shu-Chih Haw, Jin-Ming Chen, Chih-Hao Lee, Yen-Hsun Su, Jyh-Ming Ting
Summary: This study demonstrates for the first time that the OER activity of beta-FeOOH can be enhanced through V-doping and the generation of iron and oxygen vacancies. Various analyses and experiments show that V-doping regulates the formation of oxygen vacancies and metallic Fe in the beta-FeOOH, resulting in improved charge transfer characteristics. The V-doped, divacancy-containing beta-FeOOH exhibits excellent OER performance, outperforming benchmark catalysts and showing high current density and stability.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Beibei Wang, Kunyan Qian, Xiaojuan Jiao, Guanghui Yuan, Jintao Bai, Hui Wang, Gang Wang
Summary: This study presents a controllable vacancy-modulated transition metal dichalcogenide embedded porous carbon superstructure, which exhibits excellent electrochemical performance in sodium-ion batteries and dual-ion batteries.
ENERGY STORAGE MATERIALS
(2023)
Article
Chemistry, Inorganic & Nuclear
Yun Lv, Yanming Sun, Jungu Xu, Xiangyu Xu, Alberto J. Fernandez-Carrion, Tianjie Wei, Huaibo Yi, Xiaojun Kuang
Summary: In this study, a series of Ga-doped Ca12Al14-xGaxO33 materials were successfully prepared using a glass crystallization route, and their phase evolution, structures, and electrical properties were investigated. The results suggest that changing the free oxygen content through aliovalent cation substitution may be the right direction to enhance the oxide-ion conductivity in mayenite Ca12Al14O33-based materials.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Jing Guo, Ying Liu, Ping-An Chen, Xinhao Wang, Yanpei Wang, Jing Guo, Xincan Qiu, Zebing Zeng, Lang Jiang, Yuanping Yi, Shun Watanabe, Lei Liao, Yugang Bai, Thuc-Quyen Nguyen, Yuanyuan Hu
Summary: A novel p-doping mechanism is revealed by using an electrophilic attack of trityl cations on thiophenes, enabling efficient p-doping of various organic semiconductors.
Article
Chemistry, Physical
Menglan Xiao, Dawei Han, Xueqin Yang, Narcisse Tsona Tchinda, Lin Du, Yucong Guo, Yuechang Wei, Xiaolin Yu, Maofa Ge
Summary: This study constructs a Pt/Ni-CeO2 catalyst via Ni doping, which enhances the catalytic performance of toluene and improves water- and SO2-tolerance. The introduction of Ni induces the generation of abundant oxygen vacancies, facilitating the activation of oxygen species, while the formation of Pt-NiO interface structure restrains the adsorption of water and SO2 molecules.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Multidisciplinary
Kendra S. Belthle, Ute N. Gries, Michael P. Mueller, Dennis Kemp, Abhinav Prakash, Marc-Andre Rose, Jacqueline M. Boergers, Bharat Jalan, Felix Gunkel, Roger A. De Souza
Summary: The properties and concentrations of native point defects in the perovskite oxide BaSnO3 were studied using a combination of experiments and simulations. The results provide insights into the material's characteristics and stability.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Physics, Applied
A. Ardenghi, O. Bierwagen, A. Falkenstein, G. Hoffmann, J. Laehnemann, M. Martin, P. Mazzolini
Summary: The issues related to oxidation in controlling Si doping in oxide molecular beam epitaxy (MBE) were addressed by substituting solid suboxide SiO as an alternative source material. The SiO molecules were found to sublime with an activation energy of 3.3 eV. Si-doped β-Ga2O3 layers were successfully grown using this source, demonstrating unprecedented control over Si doping concentration. However, the presence of activated oxygen resulted in partial source oxidation and a decrease in doping concentration.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Nadja Ahr, Manfred Martin
Summary: The possibility of resistive switching in perovskite-type oxides using the Hebb-Wagner polarization setup is investigated. Numerical simulations and experiments demonstrate that the Hebb-Wagner setup enables bulk resistive switching of perovskite-type oxides without the need for initially high voltages. The effect of other parameters on the switching behavior is also determined.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Joe Kler, Jacqueline M. Borgers, Roger A. De Souza
Summary: The effect of surface orientation on oxygen surface exchange coefficient and surface space-charge potential in single-crystal SrTiO3 is studied. The results show that surface orientation has a significant influence on these properties.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Sylvia Koerfer, Alexander Bonkowski, Joe Kler, Peter Hatton, Blas Pedro Uberuaga, Roger A. De Souza
Summary: In this study, cation diffusion in fluorite-structured CeO2 is investigated using classical molecular dynamics and metadynamics simulations. It is found that cation diffusion primarily occurs through cation divacancies, rather than isolated vacancies or cation vacancy-oxygen vacancy associates.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Inorganic & Nuclear
Timotheus Hohl, Reinhard K. Kremer, Stefan G. Ebbinghaus, Saleem A. Khan, Jan Minar, Constantin Hoch
Summary: The two new ternary amalgams K(1-x)RbxHg(11) and Cs-3-xCaxHg(20) are examples of creating ternary compounds from binaries by statistical atom substitution. K(1-x)RbxHg(11) is a mixed crystal of KHg11 and RbHg11, while Cs-3-xCaxHg(20) is a substitution variant of the Rb3Hg20 structure type. The effect of mixed-atom occupation on the physical properties of the two amalgam systems is investigated.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Adrian L. Usler, Dennis Kemp, Alexander Bonkowski, Roger A. De Souza
Summary: Analysis of the mean squared displacement of species k as a function of simulation time allows the extraction of tracer diffusion coefficient from a molecular dynamics simulation. The statistical error in the diffusion coefficient is often underestimated. In this study, we examined the statistics of displacement curves generated by solid-state diffusion and derived a closed-form expression for the relative uncertainty in the diffusion coefficient.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Roger De Souza, George Harrington
Summary: The study of point defects in non-metallic crystals is important for various materials applications. Consistent definitions and terminology are necessary for progress in this field. This Comment clarifies the definitions of point defects, advocates for the correct use of relative charge in their description, and emphasizes their recognition as quasiparticles.
Article
Physics, Condensed Matter
Bjorn Schwarz, Stefan G. Ebbinghaus, Andreas Eichhoefer, Laura Simonelli, Holger Krause, Thomas Bergfeldt, Sylvio Indris, Jurgen Janek, Helmut Ehrenberg
Summary: A Ca12Al14O33 mayenite single crystal with 0.26(1) at.% of Ni substitution was synthesized. XRD and XAS analysis confirmed the subsitution of Ni2+ for Al on tetrahedral oxygen coordinated sites. The magnetic model reveals the presence of Ni2+ ions with spin S = 1 on distorted tetrahedral coordination sites, determining the thermomagnetic properties and uniaxial anisotropy.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Ingrid Schall, Stefan G. Ebbinghaus, Christian Strelow, Erwin Peiner
Summary: In this study, thick multicrystalline silicon layers with high orientation were successfully synthesized and characterized. The layers exhibited excellent crystallinity and showed strong bonding to the glass substrate without spalling. An aluminum-rich oxide layer was formed underneath the silicon, serving as an electrical back-contact. Impurity concentrations were found to be low, while the aluminum concentration was relatively high.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Physical
Alexander Bonkowski, Caitlin Perkampus, Roger A. De Souza
Summary: By molecular dynamics simulations, we predict that substituting Ba with Ca yields a material, Ca0.5Sr0.5Co0.8Fe0.2O3-delta, that exhibits similarly high oxygen-vacancy diffusivity in its cubic form.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Christiane Ader, Jakyu Chun, Han-Ill Yoo, Manfred Martin
Summary: The kinetic unmixing and decomposition of multinary oxides ABO(3) were investigated by treating it as a truly ternary system with defects in all three sublattices and electronic defects. The complete set of transport equations was derived and a numerical solution was obtained to investigate the time-dependence of kinetic unmixing. The results provide predictions for the lifetime of the oxide and the voltage threshold for kinetic decomposition.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Roger A. De Souza, Dennis Kemp, Matthew J. Wolf, Amr H. H. Ramadan
Summary: The activation energies of defect migration in ABX3 perovskite halides obtained through static supercell calculations may be unreliable at temperatures relevant to device operation due to local structural modifications. A robust test method is proposed to determine the reliability of static supercell calculations in point defect processes in perovskite systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Green & Sustainable Science & Technology
Fabian M. Draber, Johannes R. Denninger, Peter C. Mueller, Isabel K. Sommerfeld, Manfred Martin
Summary: This study investigates the oxygen ion conductivity of yttrium-doped BaZrO3 using density functional theory and kinetic Monte Carlo simulations. The results show that nanoscale percolation pathways are not beneficial for oxygen ion conduction due to the blocking of their motion.
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
(2022)
Article
Chemistry, Physical
Dennis Kemp, Albert Tarancon, Roger A. De Souza
Summary: In this study, we used MD and MMC simulations to determine the oxide-ion mobility in Ce1-yGdyO2-y/2 materials and proposed an analytical model to interpret the results. The findings suggest that higher oxide-ion conductivity can be achieved through non-equilibrium deposition and nanoscale-thick samples.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
