المؤلفون: Penghui Lei, Jie Lian, Dong Zhao, Tiankai Yao, Kun Yang, Yachun Wang

المصدر: Journal of the European Ceramic Society. 41:6018-6028

مصطلحات موضوعية: 010302 applied physics, Lanthanide, Materials science, Ionic radius, Valence (chemistry), Passivation, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Amorphous solid, Electronegativity, Ionic potential, Chemical engineering, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, 0210 nano-technology, Dissolution

الوصف: Chemical durability of lanthanide zirconates (A2Zr2O7) (A = La-Yb) under near-field environments is important for evaluating their application as potential nuclear waste forms. In this work, A2Zr2O7 (A = La-Yb) are synthesized by spark plasma sintering with controlled microstructure and their chemical durability are evaluated in a nitric acid solution (pH = 1). Scanning transmission electron microscopy analysis reveals an amorphous passivation film either enriched with Zr or lanthanide. The complex chemistry of the passivation films can be correlated with a transition in corrosion mechanisms from a preferential release of lanthanide in La2Zr2O7 to a preferential release of Zr in Er2Zr2O7 and Yb2Zr2O7. These results suggest a dominant mechanism of incongruent dissolution and surface reorganization for the formation of passivation films. Strong correlations are identified between the leaching rates and cation ionic size, ionic potential, electronegativity differences between A-site cation and Zr, and bonding valence sum of oxygen, suggesting important impacts of structural and bonding characteristics in controlling chemical durability of lanthanide zirconates.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::0ca54d0d906c197ae72388870d05573bTest
https://doi.org/10.1016/j.jeurceramsoc.2021.05.038Test

المؤلفون: Jie Lian, Dong Zhao, Kun Yang, Weiguang Zhu, John D. Vienna, Brian J. Riley

المصدر: Environmental Science & Technology. 55:7605-7614

مصطلحات موضوعية: chemistry.chemical_classification, Fission products, Materials science, Molten salt reactor, Halide, Salt (chemistry), Spark plasma sintering, General Chemistry, 010501 environmental sciences, 01 natural sciences, Durability, law.invention, chemistry, Chemical engineering, law, Environmental Chemistry, Leaching (metallurgy), Wet chemistry, 0105 earth and related environmental sciences

الوصف: Advanced materials and processes are required to separate halides and fission products from complex salt waste streams associated with the chemical reprocessing of used nuclear fuels and molten salt reactor technologies for immobilization into chemically durable waste forms. In this work, we explore an innovative concept using metal halide perovskites as advanced host phases to incorporate Cs and Cl with very high waste loadings. Wet chemistry-synthesized Cs2SnCl6 powders from CsCl salt solutions are successfully encapsulated into a silica matrix to form a composite using low-temperature spark plasma sintering with tunable Cs and Cl loadings up to 31 and 26 wt %, respectively. Chemical durability testing of the composite waste forms by semi-dynamic leaching experiments demonstrates that an incongruent leaching mechanism dominates the release of Cs and Cl. The metal halide perovskite-silica composite waste forms display exceptional chemical durability with the long-term release rates of Cs and Cl comparable to or outperforming the state-of-the-art waste form materials but with significantly higher waste loadings. The scalable synthesis of the metal halide perovskite from wet chemistry processes opens up new opportunities in designing advanced waste forms for salt wastes with very high waste loadings and exceptional chemical durability for the sustainable development of advanced fuel cycles and next-generation reactor technologies.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::632c997d2aadbf48d48f07090b0754dbTest
https://doi.org/10.1021/acs.est.0c07724Test

المؤلفون: Jin-Yu Zhao, Jie Lian, Xiao-Min Wang

المصدر: Acta Metallurgica Sinica (English Letters). 34:885-899

مصطلحات موضوعية: 010302 applied physics, Materials science, Graphene, Heteroatom, Metals and Alloys, Proton exchange membrane fuel cell, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, Carbon nanotube, 021001 nanoscience & nanotechnology, Electrocatalyst, 01 natural sciences, Industrial and Manufacturing Engineering, law.invention, Catalysis, chemistry, law, 0103 physical sciences, 0210 nano-technology, Porosity, Carbon

الوصف: Proton exchange membrane fuel cell (PEMFC) has important implications for the success of clean transportation in the future. One of the key factors affecting the cost and performance of PEMFC is the cathode electrocatalyst for the oxygen reduction reaction (ORR) to overcome sluggish kinetics and instability in an acidic environment. As an essential component of the electrocatalyst, the support material largely determines the activity, mass transfer, charge transfer, and durability of the electrocatalyst. Thereby, the support material plays a critical role in the overall performance of the electrocatalyst. Carbon-based materials are widely used as electrocatalyst supports because of their high porosity, conductivity, chemical stability, and tunable morphology. Recently, some new carbon-based materials with excellent structure have been introduced, such as carbon nanotubes, carbon nanowires, graphene, metal–organic framework (MOF)-derived carbon, and biomass-derived carbon materials. Combined with a variety of strategies, such as controllable construction of porous structures and surface defects, proper doping heteroatoms, the ingenious design of model electrocatalysts, and predictive theoretical calculation, a new reliable path was provided for further improving the performance of electrocatalysts and exploring the catalytic mechanism. Based on the topic of carbon-based materials for ORR in acidic medium, this review summarizes the up-to-date progress and breakthroughs, highlights the factors affecting the catalytic activity and stability of ORR electrocatalysts in acids, and discusses their future application and development.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a1c343f5f05ea833160184a25158078fTest
https://doi.org/10.1007/s40195-021-01229-xTest

المؤلفون: Jie Lian, Dong Zhao, Weiguang Zhu, Kun Yang, Keith Bryce

المصدر: Journal of the European Ceramic Society. 41:2870-2882

مصطلحات موضوعية: 010302 applied physics, Materials science, Pyrochlore, Oxide, Mixing (process engineering), chemistry.chemical_element, Radioactive waste, Thermodynamics, 02 engineering and technology, engineering.material, Uranium, 021001 nanoscience & nanotechnology, 01 natural sciences, Titanate, chemistry.chemical_compound, Thermal conductivity, chemistry, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, engineering, 0210 nano-technology, Solid solution

الوصف: Multicomponent pyrochlore solid solutions with and without uranium incorporation were fabricated and their thermal-mechanical properties were characterized. Multicomponent pyrochlore solid solutions without uranium exhibit comparable thermal conductivity and higher mechanical strength compared to baseline single component rare-earth titanate pyrochlore (A2Ti2O7). Uranium incorporation reduces hardness as compared with single component compositions. High entropy pyrochlore with uranium displays the highest thermal conductivity within multicomponent pyrochlore solid solutions with significantly better mechanical properties than UO2. The measured thermal conductivity correlates well with A-site cation mixing entropy and a modified size disorder parameter, and thus the size disorder and mixing entropy could be good indicators for predicting thermal conductivity of multicomponent pyrochlore solid solutions. This work opens up the possibility of designing multicomponent oxide solid solutions by controlling their chemical disorder/mixing entropy to achieve acceptable thermal-mechanical properties, desired radiation and corrosion performance for potential nuclear waste form and inert matrix fuel applications.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::ad1f0b5d2065c0da5df65ce83069826bTest
https://doi.org/10.1016/j.jeurceramsoc.2020.12.012Test

المؤلفون: Jie Lian, Weiguang Zhu, Gerald S. Frankel, Xiaolei Guo, Yachun Wang, Tiankai Yao

المصدر: MRS Communications. 10:687-694

مصطلحات موضوعية: Aqueous solution, Materials science, Passivation, Moisture, Halide, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Chemical engineering, Degradation (geology), General Materials Science, Leaching (metallurgy), 0210 nano-technology, Layer (electronics), Perovskite (structure)

الوصف: To improve the stability of Cs2SnCl6 under aqueous/moisture environments, we applied a concept of artificial passivation by depositing a protective TiO2 coating of 10 nm on the surface of Cs2SnCl6. Static leaching experiments results indicate that the initial release rates of Cs+ and Cl− are decreased by 20–30 times with TiO2 coating, suggesting its possibility to improve the short-term water/environmental stability of Cs2SnCl6. An amorphous-to-crystalline phase transition in TiO2 film was observed, possibly resulting in degradation of Cs2SnCl6. However, the crystalline TiO2 film still remains after 21 days water exposure and can still act as an effective passivation layer to reduce the release rates of Cs+ and Cl− by as much as about 17 and 7 times, respectively, relative to static leaching without artificial coatings. Therefore, the water/environmental stability of metal halide perovskite Cs2SnCl6, which is a highly soluble molecular salt, can be enhanced by the nanoscale TiO2 coating as an artificial passivation film.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::cf591ad48641efeb8e35dd91a0e3a977Test
https://doi.org/10.1557/mrc.2020.84Test

المؤلفون: Edward Jean Lahoda, Peng Xu, Jie Lian, Penghui Lei, Bowen Gong, Tiankai Yao, Cai Lu

المصدر: Ceramics International. 46:26486-26491

مصطلحات موضوعية: 010302 applied physics, Materials science, Nuclear fuel, Annealing (metallurgy), Process Chemistry and Technology, Pellets, Neutron poison, Oxide, Sintering, Spark plasma sintering, chemistry.chemical_element, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, chemistry.chemical_compound, chemistry, Chemical engineering, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, 0210 nano-technology, Boron

الوصف: The boron isotope (10B) can be used as a neutron absorber in UO2 to control the reactivity of nuclear fuel pellets, however, the boron source can react with oxygen source in UO2 to form B2O3 that vaporize readily at temperatures above 1200 °C. Unfortunately, the sintering of UO2 fuel requires hours holding at high temperature (>1700 °C), resulting in an inevitable B loss during sintering and unpredictable B concentration in final product. It is challenging to incorporate boron through a conventional sintering method. In this work, we demonstrated that spark plasma sintering (SPS), a field assisted sintering technology, can effectively densify UO2 ​+ ​5 ​vol% ZrB2 composite fuel pellets by rapid consolidation at 1600 °C for a short duration of 5 min under an applied pressure of 40 MPa. Thermogravimetric analysis (TGA) measurements confirm that ZrB2 is fully retained inside the composite fuel pellets. Inside the composite fuel pellets, nano sized ZrB2 particles are uniformly distributed along the grain boundaries of the UO2 matrix. The ZrB2 particle transforms to a glassy B2O3 phase covering the sample surface and grain boundaries of UO2 matrix after a simple post-sintering annealing at 1000 °C in flowing Argon gas for 4 h. The formed glassy B2O3 slows down the diffusion of oxygen ions and postpones the onset temperature for oxidation of UO2 from 400 °C to 550 °C. This study demonstrates the capability of SPS, an advanced fuel manufacturing technique, to achieve a full retention of ZrB2 in UO2 oxide fuel and increase oxidation resistance through a simple post-sintering annealing. The reported work holds great engineering potential for development of advanced oxide fuel for nuclear application.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::f58a44d6e8ce69136607f7a92604baceTest
https://doi.org/10.1016/j.ceramint.2020.06.303Test

المؤلفون: Yang Xu, Jie Lian, Yinthai Chan, Deepshikha Arora, Wen-Ya Wu

المصدر: ACS Nano. 14:10337-10345

مصطلحات موضوعية: Facet (geometry), Materials science, General Engineering, General Physics and Astronomy, Nanotechnology, 02 engineering and technology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Condensed Matter::Materials Science, Semiconductor nanocrystals, General Materials Science, 0210 nano-technology, Semiconductor Nanoparticles, Semiconductor heterostructures

الوصف: Branched heterostructured semiconductor nanoparticles such as core seeded tetrapods and octapods offer properties not seen in their spherical core-shell counterparts, but are challenging to synthes...

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::2849eada87a06e7473596ba417db4438Test
https://doi.org/10.1021/acsnano.0c03837Test

المؤلفون: Tiankai Yao, Xiaolei Guo, Penghui Lei, Yachun Wang, Gerald S. Frankel, Jie Lian

المصدر: npj Materials Degradation, Vol 4, Iss 1, Pp 1-10 (2020)

مصطلحات موضوعية: 010302 applied physics, Chemistry (miscellaneous), Materials Science (miscellaneous), 0103 physical sciences, Materials Chemistry, Ceramics and Composites, lcsh:TA401-492, lcsh:Materials of engineering and construction. Mechanics of materials, 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, 01 natural sciences

الوصف: This paper studied the release of iodine from lead vanado-iodoapatite (I-APT, Pb9.85(VO4)6I1.7), a potential nuclear waste form for the radioactive waste element of I-129, which can be enhanced when crevice corrosion of stainless steel (SS) occurring nearby. Reference corrosion studies of I-APT were performed in different bulk solutions including DI water, 0.6 M and 6 M NaCl, and 0.1 M HNO3 without metal crevice corrosion interactions. The localized enrichment of Cl−, one of the major consequences of SS crevice corrosion, was found to be the decisive factor that led to the enhanced release of iodine. A surface alteration layer consisting of a mixture of nanocrystalline I-APT and Cl-rich apatite (Cl-APT) formed on I-APT surface. Meanwhile, large Cl-APT crystals formed at the crevice mouth on the I-APT surface. This study reveals a new near-field corrosion mechanism for ceramic waste forms when they are exposed to aggressive local corrosive conditions created by the electrochemical reactions of nearby metals. The insight gained in this study could be beneficial for a more accurate prediction of waste form degradation.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2e2aef5096116fc0d83b425c4aace016Test
http://link.springer.com/article/10.1038/s41529-020-0119-9Test

المؤلفون: Yangchun Zhu, Lijin Wang, Xueyong Zhao, Jie Lian, Zhenhua Zhang

المصدر: Pedosphere. 30:244-252

مصطلحات موضوعية: 021110 strategic, defence & security studies, Soil test, business.industry, 0211 other engineering and technologies, Soil Science, 02 engineering and technology, 010501 environmental sciences, Pesticide, Contamination, 01 natural sciences, Soil contamination, Irrigation district, Mining engineering, Agriculture, Environmental chemistry, Soil water, Environmental science, Soil horizon, business, 0105 earth and related environmental sciences

الوصف: Soil contamination by heavy metal is an important problem in agricultural irrigation systems in recent years. To assess the accumulation of, and identify the sources of heavy metals in the Hetao Irrigation District, 195 soil samples from 39 sites of 0-100 cm soil layers were collected and analyzed for heavy metal concentrations of Zn, Cu, Pb, Cr, and Cd. The results indicated that the mean values for these five heavy metals were 107.17, 32.48, 12.31, 53.53, and 0.22 mg kg−1, respectively and insignificantly differed among the soil depths of 0-20, 20-40, 40-60, 60-80 and 80-100 cm (p > 0.05). Zn, Cu, and Cd concentrations were higher than the background levels of the Hetao area, with a moderate accumulation: the mean values of the contamination factor (CF) were 1.9, 1.7 and 1.9, respectively, and the geoaccumulation index (Igeo) was > 0 for these three elements; Pb and Cr concentrations were lower than or close to the background levels, with CF < 1 and Igeo < 0, indicating origination from a natural source. Values of the monomial potential ecological risk index (Eri) for Zn, Cu, Pb, and Cr were much lower. However, the mean value of Eri for Cd was 55.73, implying a moderate risk in the soils. The ecological risk (RI) of the five heavy metals was much lower, with the mean content of 77.18, declining from the south to the north of the district. In our study, the soils were previously contaminated with Zn, Cu, and Cd, and the results of principal component analysis (PCA) revealed that two different anthropogenic sources were indicated (PC2 and PC3). The enrichment of Cd and, partially, of Cu, heavier in PC2, was related to agricultural activities, such as excessive application of commercial fertilizers, pesticides, and livestock manures among others. Zn and partly Cu, closely associated with PC3, may have originated from irrigation water derived from the Yellow River. In the future, development of agriculture should pay more attention to the application of fertilizers and pesticides and the quality of irrigation water in the irrigation district.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::dd4e889c1c23fbd50dbcdd0a6529623bTest
https://doi.org/10.1016/s1002-0160Test(17)60306-0

المؤلفون: Jie Lian, Stéphane Gin, Tianshu Li, Gopal B. Viswanathan, Tiankai Yao, Gerald S. Frankel, John D. Vienna, Xiaolei Guo, Penghui Lei, Jincheng Du, Seong H. Kim, Daniel K. Schreiber, Hongshen Liu, Dien Ngo, Joseph V. Ryan

المصدر: Nature Materials. 19:310-316

مصطلحات موضوعية: Waste management, Mechanical Engineering, Radioactive waste, 02 engineering and technology, General Chemistry, Solution chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, Corrosion, Mechanics of Materials, visual_art, Service life, visual_art.visual_art_medium, Environmental science, General Materials Science, Ceramic, 0210 nano-technology

الوصف: The US plan for high-level nuclear waste includes the immobilization of long-lived radionuclides in glass or ceramic waste forms in stainless-steel canisters for disposal in deep geological repositories. Here we report that, under simulated repository conditions, corrosion could be significantly accelerated at the interfaces of different barrier materials, which has not been considered in the current safety and performance assessment models. Severe localized corrosion was found at the interfaces between stainless steel and a model nuclear waste glass and between stainless steel and a ceramic waste form. The accelerated corrosion can be attributed to changes of solution chemistry and local acidity/alkalinity within a confined space, which significantly alter the corrosion of both the waste-form materials and the metallic canisters. The corrosion that is accelerated by the interface interaction between dissimilar materials could profoundly impact the service life of the nuclear waste packages, which, therefore, should be carefully considered when evaluating the performance of waste forms and their packages. Moreover, compatible barriers should be selected to further optimize the performance of the geological repository system. Immobilization of radionuclides in glass or ceramic forms in stainless steel in deep geological repositories is planned in the US for disposal of nuclear waste. Under simulated repository conditions, corrosion could be significantly accelerated at the interfaces of different barrier materials.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::630a8100786354fe7332111909b152bbTest
https://doi.org/10.1038/s41563-019-0579-xTest