Article
Materials Science, Ceramics
Young-Il Kim, Maxim Avdeev
Summary: Perovskite lattice was modified with site vacancies and mixed anion composition to create Sr0.83Li0.17Ta0.83O1.88N0.74 (Li02N), which was further transformed into Sr0.83Li0.17Ta0.83O3 (Li02O) with optimized treatment. Both Li02N and Li02O showed Arrhenius behavior of ionic conductivity with different activation energies, suggesting that the nitride component enhances ionic conduction while anion lattice vacancies have the opposite effect.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Yin Zhang, Yuchen Yang, Xiao Hou, Feihai Yu, Qisheng Feng, Baohua Duan, Xionggang Lu, Rongbin Li, Guangyao Chen, Chonghe Li
Summary: In this study, a novel perovskite oxyfluoride BaY0.5Zr0.5O2.5F0.5 was successfully synthesized and characterized. The purity and grain morphology of BaY0.5Zr0.5O2.5F0.5 were found to be favorable under specific synthesis conditions. Additionally, the introduction of F ions improved the stability of the compound.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Inorganic & Nuclear
Kei Saito, Kotaro Fujii, Masatomo Yashima
Summary: BaY1/3Ga2/3O2.5 is a new type of mixed oxide-ion and proton conductor, with a high chemical and electrical stability, belonging to a new structure family of oxide-ion and proton conductors.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Chemistry, Physical
Yaoyao Han, Wenfei Liang, Xuyang Lin, Yulu Li, Fengke Sun, Fan Zhang, Peter C. Sercel, Kaifeng Wu
Summary: The study reports strong bright-exciton fine-structure splitting in solution-processed CsPbI3 perovskite quantum dots, which is robust to quantum dot size and shape heterogeneity and increases with decreasing temperature. The splitting is found to be associated with orthorhombic distortion of the perovskite lattice.
Article
Chemistry, Physical
Sahil Dani, A. Arya, Hitesh Sharma, Rakesh Kumar, Navdeep Goyal, Ravi Kumar, Rabia Pandit
Summary: We investigated the structural, electronic, and vibrational characteristics of Ba2GdRuO6 and Sr2GdRuO6 double perovskite ruthenates through experimental and theoretical analysis. The experimental results revealed that Ba2GdRuO6 has a cubic structure, while Sr2GdRuO6 has a monoclinic structure. The theoretical calculations matched well with the experimental values. These findings are important for a better understanding of the properties of these materials.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Dinesh Kumar, Chandra Bhal Singh, Akhilesh Kumar Singh
Summary: La3Ni2NbO9 (LNNO) nanoparticles were synthesized by the glycine-nitrate combustion technique and calcination process, with an average crystallite size of 25 nm. XRD analysis revealed that LNNO crystallizes in a monoclinic crystal structure with P21/n space group. Magnetization measurements showed that LNNO nanoparticles undergo a paramagnetic to antiferromagnetic phase transition at 43 K (Neel temperature) and an antiferromagnetic to spin glass transition at 31.45 K (Tg). AC-susceptibility measurements indicated that LNNO nanoparticles followed the Vogel-Fulcher and dynamic scaling power laws in the low-temperature region.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Physical
Jiaxin Gong, Jiheng Li, Xiaoqian Bao, Ruifen Hou, Xuexu Gao
Summary: The crystal structure and magnetic structure of Tb-Dy-Fe compounds were studied before and after annealing heat treatment, revealing the existence of tetragonal and rhombohedral phases at room temperature. The volume proportion of the hexagonal phase increased after heat treatment, and the effect of structural distortion on the magnetostriction of Tb-Dy-Fe was discussed based on analytical results.
Article
Chemistry, Physical
Kenji Iwase, Shuhei Ishida, Takashi Ueno, Kazuhiro Mori
Summary: This study investigated the residual hydrogen occupation mechanisms in MgZn2-type and CaCu5-type cells during the hydrogen absorption-desorption process. The results revealed the structural changes and deuterium occupation in NdNi3Dx and provided insights into the preferred deuterium sites in different cell types.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Neha Solanki, R. J. Choudhary, Netram Kaurav
Summary: La2CoTi(1-x)NixO6 (x = 0, 0.2 and 0.6) double perovskite samples were successfully prepared in bulk pellet form using sol-gel method at a sintering temperature of 1350 degrees C. The crystal structures of the samples were investigated using X-ray powder diffraction data, revealing a structural phase transition from monoclinic to orthorhombic to rhombohedral as the nickel content increased. X-ray photoelectron spectroscopy study showed significant changes in the oxidation state of cobalt ions and bond length as the nickel concentration increased.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Harikrishnan Ravichandran, Baskaran Irusan, Sathyaseelan Balaraman, Mani Govindasamy, Senthilnathan Krishnamoorthy, Manikandan Elayaperumal
Summary: In this study, rare earth Erbium metal incorporated orthoferrite nanoparticles were successfully synthesized and characterized using microwave-assisted technique. The unit cell structure was confirmed to belong to the orthorhombic-cubic phase with slightly induced distortion in bond distance between atoms. The vibrational frequencies of Er-O and Fe-O groups were observed and calculated, with a band gap of 2.1 eV and weak ferromagnetic property observed in the synthesized nanoparticles.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Ceramics
Ankit Kumar, Pravin Kumar, A. S. Dhaliwal
Summary: By studying the phase evolution of calcium-doped zirconia after sintering at 1400 degrees C, it was found that with increasing calcium doping, the cubic phase in zirconia develops and achieves near-total stabilization at 16 mol-% doping of calcium. The findings were validated through microstructure and elemental analyses, as well as Raman spectroscopic studies, indicating potential applications in new technology such as oxygen sensors and solid electrolytes.
ADVANCES IN APPLIED CERAMICS
(2021)
Article
Chemistry, Multidisciplinary
Dinesh Kumar, Akhilesh Kumar Singh
Summary: The effects of Ti-doping on the structural and magnetic behavior of La0.6Ba0.4Mn1-xTixO3-delta (0.02 <= x <= 0.08) manganites were investigated. Increasing the Ti-ions concentration resulted in an increase in unit cell lattice parameter 'a' and volume 'V', indicating the substitution of Mn-ions by larger Ti-ions in the lattice. Temperature-dependent magnetization measurements showed a non-linear decrease in the Curie temperature (TC) as the concentration of Ti-ions increased. An abnormal behavior in the experimental paramagnetic moment and the appearance of a Griffiths phase were observed with Ti substitution. The larger experimental saturation moment compared to theoretical values indicated the possibility of spin-orbit coupling.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Materials Science, Multidisciplinary
Niketa Bajpai, Mohd Saleem, Ashutosh Mishra
Summary: In this study, La-1.Y-95(0).05NiMnO6 and La1.9Sm0.05Y0.05NiMnO6 double perovskite multiferroic materials were synthesized by solid-state reaction technique and characterized using XRD for structural and phase formation studies. The samples were found to have a highly crystalline monoclinic structure with large crystallite size and tensile strain. Both samples exhibited good dielectric constant with lower loss values and semiconductor nature was confirmed through magnetic field dependent electrical resistivity measurements.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Chemistry, Inorganic & Nuclear
Matilde Saura-Muzquiz, Maxim Avdeev, Helen E. A. Brand, Brendan J. Kennedy
Summary: The structures and magnetic properties of Os4+ (5d4) halides are described, and the crystal structures and thermal stability of different compounds are studied. The experimental results show that these compounds exhibit unique magnetic behavior with a weak magnetic ground state.
INORGANIC CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Shreyas J. Kashyap, Ravi Sankannavar, G. M. Madhu
Summary: La1-xCaxFeO3 perovskite-type oxides were synthesized using combustion technique and characterized using various analytical methods. The results suggest that these samples have potential for photocatalytic applications, and calcium doping can alter the structure and properties of the material.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Environmental Sciences
Carlos J. Pestana, Jianing Hui, Dolores Camacho-Munoz, Christine Edwards, Peter K. J. Robertson, John. T. S. Irvine, Linda A. Lawton
Summary: Cyanobacteria and their toxins pose a threat to drinking water safety, and using solar light active photocatalysts is a low-cost method to purify water. A recycled glass bead method was used to obtain TiO2 and g-C3N4 coated floating photocatalysts. The results showed that g-C3N4 and TiO2+g-C3N4 coated beads were more effective than TiO2 coated beads in removing cyanotoxins from water.
Article
Green & Sustainable Science & Technology
Md Sumon Reza, Juntakan Taweekun, Shammya Afroze, Shohel Ahmed Siddique, Md. Shahinoor Islam, Chongqing Wang, Abul K. Azad
Summary: Barley waste has been found to have a high potential as a feedstock for renewable energy. Thermochemical characterization and pyrolysis analysis showed that it can generate significant amounts of biochar, bio-oil, and syngas. This study is of great importance for the development of renewable energy sources.
Review
Chemistry, Physical
Yathavan Subramanian, Anitha Dhanasekaran, Lukman Ahmed Omeiza, Mahendra Rao Somalu, Abul K. K. Azad
Summary: In recent decades, photocatalysis has emerged as a practical and environmentally friendly method for degrading pollutants and generating fuels using solar light. Traditional photocatalysts face limitations such as wider band gaps and quick recombination rates, prompting the search for alternative materials. Heteroanionic materials are seen as a promising solution due to their superior light absorption capacity, narrow band gaps, and improved resistance to corrosion. This article summarizes the recent developments in heteroanionic materials, their classification, synthesis techniques, and their role in photocatalysis.
Article
Chemistry, Multidisciplinary
Mei Wang, Evangelos I. Papaioannou, Ian S. Metcalfe, Aaron Naden, Cristian D. Savaniu, John T. S. Irvine
Summary: Copper (Cu) is an important catalyst in industrial catalysis, and controlling the size and distribution of Cu nanoparticles is crucial in optimizing its performance. Despite the potential of proton conducting perovskites as supports, there has been limited research on the in situ growth of Cu nanoparticles from these materials and their catalytic performance. In this study, Cu nanoparticles were observed to exsolve from an A-site-deficient proton-conducting barium cerate-zirconate, and a new exsolution mechanism was proposed for the first time. Furthermore, the catalytic behavior of these Cu nanostructures in CO oxidation reaction was explored, and it was found that they can rival state-of-the-art catalysts over long-term operation.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Thermodynamics
Duncan A. Nowicki, Gerry D. Agnew, John T. S. Irvine
Summary: This article presents a conceptual design for a small-scale green ammonia plant, where ammonia synthesis is achieved by reacting hydrogen produced by a solid oxide electrolyzer with nitrogen purified from air using a series of solid electrolyte oxygen pumps. The system operates with an energetic efficiency of 52.12%, which is very close to a cryogenic ASU reference system achieving an efficiency of 52.89%. The specific energy consumption is 9.94 kWh/kgNH3. Although these results are promising, there are opportunities to further improve the system design, such as enhancing heat integration to utilize waste heat from the series of oxygen pumps for raising the steam required by the electrolyzer.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Energy & Fuels
Jianjun Ma, Yao Jiang, Paul A. Connor, Stephen R. Gamble, Mark Cassidy, Cairong Jiang, John T. S. Irvine
Summary: Ni-YSZ is a common anode for solid oxide fuel cells (SOFCs) due to its excellent catalytic performance and electronic conductivity. However, natural biogas fuels often contain sulfur, which complicates the use of nickel anodes. This paper investigates sulfur poisoning and the recovery of BCZYYb- impregnated nickel anode-supported cells in biogas. The research reveals that the suppression of reforming reactions might cause sulfur poisoning, and the degradation of current in working conditions is attributed to the deactivation of reforming reactions and catalyst activity.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2023)
Article
Chemistry, Physical
Ahmed Umar, Dragos Neagu, John T. S. Irvine
Summary: This study focuses on the development of catalyst design for energy applications, particularly biomass conversion. The use of ceria to enhance the structural and catalytic behavior of metal catalysts in glycerol steam reforming is investigated. The study reveals that ceria significantly influences the exsolution and surface morphology of metal catalysts, leading to improved catalytic behavior and resistance to carbon deposition. The catalyst systems with exsolvable dopant metals, such as Fe and Co, show even better results. Moreover, the study extends the tolerance limit of A-site deficiency and doping in perovskite systems, resulting in enhanced defect chemistry and suppression of coke deposition. The catalyst systems demonstrate high selectivity for CO and H2, making them valuable for energy production and the synthesis of value-added chemicals.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Yathavan Subramanian, Anitha Dhanasekaran, Lukman Ahmed Omeiza, Juliana Haji Zaini, John T. S. Irvine, Abul K. Azad
Summary: Combining a rational design strategy with a simple synthetic method, this work successfully synthesized an eco-friendly material, heteroanionic titanium oxycarbide photocatalyst-TiOC, which was used for the decomposition of Congo red (CR) and H2O2 generation from water. Initially, TiOC showed a moderate CR degradation efficiency of 54% (1 g/L) in 120 min and produced a minimal amount of H2O2 after 90 min (2 mmol) and 120 min (10 mmol) of light exposure. However, with the use of sacrificial reagents such as H2O2 and isopropyl alcohol (ISA), the CR removal and H2O2 evolution rate were improved to 70% and 21.5 mmol (120 min), respectively.
Article
Chemistry, Physical
Lanying Lu, Debo He, Rong Fang, Chengsheng Ni, John T. S. Irvine
Summary: The valorization of CO2 greenhouse gas is important in decarbonization using renewable energies. Intermediate temperature solid oxide electrolysis cells (SOEC) can activate the strong C-O bond in CO2 for the production of CO and decrease electricity consumption. In this study, a composite oxide/metal cathode with ceria/Co doping on stable chromite is designed for direct CO2 electrolysis. The unique heterojunction structure formed by ceria exsolution and Co0 outgrowth from the B site enables efficient CO2 activation and high electrochemical performance.
JOURNAL OF POWER SOURCES
(2023)
Article
Electrochemistry
Xiaoqiang Zhang, Danan Yang, Min Xu, Aaron Naden, Mayken Espinoza-Andaluz, Tingshuai Li, John T. S. Irvine, Martin Andersson
Summary: This paper investigates the tortuosity of gas transport in solid oxide fuel cells (SOFCs) using different approaches. The test results show that decreased Ni content in the anode leads to decreased cell performance and increased tortuosity. Different methods yield different tortuosity values.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Shangshang Zuo, Yuan Liao, Chenchen Wang, Aaron B. Naden, John T. S. Irvine
Summary: Perovskite-based catalysts for oxygen evolution reaction (OER) have tunable compositions and adaptable characteristics, but can suffer from limited atom utilization efficiency. This study demonstrates that exsolving cobalt nanoparticles from perovskite improves the OER performance, achieving higher mass activity and stability.
Review
Engineering, Chemical
Md. Mosfiqur Rahman, Abdalla M. Abdalla, Lukman Ahmed Omeiza, Veena Raj, Shammya Afroze, Md. Sumon Reza, Mahendra Rao Somalu, Abul K. Azad
Summary: Solid oxide fuel cells with protonic ion conducting electrolytes (H-SOFCs) have fuel flexibility, and using ammonia as a fuel in these cells has advantages of ammonia cracking attributes and easy separation from generated steam, without formation of toxic gases. Numerical studies have been applied to optimize the design of ammonia-fueled H-SOFCs under different operating conditions.
Article
Engineering, Chemical
Nur Hanisah Hadi, Mahendra Rao Somalu, Abdullah Abdul Samat, Wan Nor Anasuhah Wan Yusoff, Andanastuti Muchtar, Nurul Akidah Baharuddin, Muhammed Ali Shaikh Abdul, Jarot Raharjo, Deni Shidqi Khaerudini, Abdalla M. Abdalla, Abul Kalam Azad
Summary: Investigating the influence of sintering temperature on the physical and chemical properties of Ni-BaCe0.54Zr0.36Y0.1O3-(Ni-BCZY) composite anode is important for its potential application in protonic ceramic fuel cells (PCFCs). The study found that the NiO-BCZY composite powder, prepared using citric acid as the chelating agent, showed optimal properties when sintered at 1100°C, with a single cubic phase structure and homogeneous particles with an average size of 51 nm.
Article
Environmental Sciences
Mosaad Negem, David Miller, John Irvine, Fakiha El-Taib Heakal
Summary: Efficient photocatalysts, BixSn6-2xSy, with varying morphological structures have been synthesized using the nanoemulsion tactic. These materials exhibit appreciable absorption in the UV-visible light range and their photocatalytic activity is greatly affected by crystal structure and composition. Among the synthesized photocatalysts, BiSn4S4.5 shows the highest activity in photodegrading methylene blue dye under UV-visible light.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Physical
Gavin J. Irvine, John T. S. Irvine
Summary: Nitrogen-hydrogen based alkali and alkaline earth metal compounds have become important co-catalysts for ammonia synthesis. These compounds solve the issue of hydrogen poisoning by incorporating H-adatoms and reducing the inhibition of N-2 dissociation. The conductivity of H and N ions, as well as NHx species, plays a crucial role in the properties of these co-catalysts.
FARADAY DISCUSSIONS
(2023)
