Pub Date : 2024-10-09DOI: 10.1038/s43246-024-00667-1
Guixin Hou, Shengyu Zhu, Hui Tan, Wenyuan Chen, Jiao Chen, Qichun Sun, Juanjuan Chen, Jun Cheng, Peixuan Li, William Yi Wang, Jun Yang, Weimin Liu
Achieving near-zero-wear remains a major challenge in mechanical engineering and material science. Current ultra-low wear materials are typically developed based on the self-consumption strategy. Here, we demonstrate a new self-repairing approach to achieve near-zero-wear. We find that the WB4-βB/WC tribo-pair has a low wear rate of 10−8 mm3 N−1 m−1 in low vacuum conditions, under a maximum Hertzian contact stress of 2.23 GPa over 1 × 105 friction cycles. Additionally, we observe an abnormal wear phenomenon after 5 × 104 friction cycles, characterized by an increase in the dimensions of the tribo-pair. This near-zero-wear mechanism is attributed to the synergistic action of the super-hard WB4-βB substrate and the self-repairing tribo-oxide layer. This research provides a new approach for advancing wear-resistant materials and enhancing material longevity. Expanding the range of ultra-low-wear material systems would benefit a number of applications. Here, near-zero-wear is reported in a WB4-βB/WC tribo-pair system, attributed to surface self-repair in a certain wear regime.
{"title":"Near-zero-wear with super-hard WB4 and a self-repairing tribo-chemical layer","authors":"Guixin Hou, Shengyu Zhu, Hui Tan, Wenyuan Chen, Jiao Chen, Qichun Sun, Juanjuan Chen, Jun Cheng, Peixuan Li, William Yi Wang, Jun Yang, Weimin Liu","doi":"10.1038/s43246-024-00667-1","DOIUrl":"10.1038/s43246-024-00667-1","url":null,"abstract":"Achieving near-zero-wear remains a major challenge in mechanical engineering and material science. Current ultra-low wear materials are typically developed based on the self-consumption strategy. Here, we demonstrate a new self-repairing approach to achieve near-zero-wear. We find that the WB4-βB/WC tribo-pair has a low wear rate of 10−8 mm3 N−1 m−1 in low vacuum conditions, under a maximum Hertzian contact stress of 2.23 GPa over 1 × 105 friction cycles. Additionally, we observe an abnormal wear phenomenon after 5 × 104 friction cycles, characterized by an increase in the dimensions of the tribo-pair. This near-zero-wear mechanism is attributed to the synergistic action of the super-hard WB4-βB substrate and the self-repairing tribo-oxide layer. This research provides a new approach for advancing wear-resistant materials and enhancing material longevity. Expanding the range of ultra-low-wear material systems would benefit a number of applications. Here, near-zero-wear is reported in a WB4-βB/WC tribo-pair system, attributed to surface self-repair in a certain wear regime.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00667-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1038/s43246-024-00655-5
Alexander Feichtmayer, Max Boleininger, Johann Riesch, Daniel R. Mason, Luca Reali, Till Höschen, Maximilian Fuhr, Thomas Schwarz-Selinger, Rudolf Neu, Sergei L. Dudarev
The occurrence of high stress concentrations in reactor components is a still intractable phenomenon encountered in fusion reactor design. Here, we observe and quantitatively model a non-linear high-dose radiation mediated microstructure evolution effect that facilitates fast stress relaxation in the most challenging low-temperature limit. In situ observations of a tensioned tungsten wire exposed to a high-energy ion beam show that internal stress of up to 2 GPa relaxes within minutes, with the extent and time-scale of relaxation accurately predicted by a parameter-free multiscale model informed by atomistic simulations. As opposed to conventional notions of radiation creep, the effect arises from the self-organisation of nanoscale crystal defects, athermally coalescing into extended polarized dislocation networks that compensate and alleviate the external stress. The creep behavior of actively cooled alloys exposed to neutron irradiation in fusion reactors is expected to critically affect the operation of reactor components. Here, experiments and simulations of a 16 μm thick tungsten wire exposed to low-temperature irradiation reveal stress relaxation rates far exceeding those associated with thermal creep.
{"title":"Fast low-temperature irradiation creep driven by athermal defect dynamics","authors":"Alexander Feichtmayer, Max Boleininger, Johann Riesch, Daniel R. Mason, Luca Reali, Till Höschen, Maximilian Fuhr, Thomas Schwarz-Selinger, Rudolf Neu, Sergei L. Dudarev","doi":"10.1038/s43246-024-00655-5","DOIUrl":"10.1038/s43246-024-00655-5","url":null,"abstract":"The occurrence of high stress concentrations in reactor components is a still intractable phenomenon encountered in fusion reactor design. Here, we observe and quantitatively model a non-linear high-dose radiation mediated microstructure evolution effect that facilitates fast stress relaxation in the most challenging low-temperature limit. In situ observations of a tensioned tungsten wire exposed to a high-energy ion beam show that internal stress of up to 2 GPa relaxes within minutes, with the extent and time-scale of relaxation accurately predicted by a parameter-free multiscale model informed by atomistic simulations. As opposed to conventional notions of radiation creep, the effect arises from the self-organisation of nanoscale crystal defects, athermally coalescing into extended polarized dislocation networks that compensate and alleviate the external stress. The creep behavior of actively cooled alloys exposed to neutron irradiation in fusion reactors is expected to critically affect the operation of reactor components. Here, experiments and simulations of a 16 μm thick tungsten wire exposed to low-temperature irradiation reveal stress relaxation rates far exceeding those associated with thermal creep.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00655-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1038/s43246-024-00657-3
Arthur Mantel, Berthold Stöger, Alexander Prado-Roller, Hidetsugu Shiozawa
Methods to grow large crystals provide the foundation for material science and technology. Here we demonstrate single crystal homoepitaxy of a metal-organic framework (MOF) built of zinc, acetate and terephthalate ions, that encapsulate arrays of octahedral zinc dimethyl sulfoxide (DMSO) complex cations within its one-dimensional (1D) channels. The three-dimensional framework is built of two-dimensional Zn-terephthalate square lattices interconnected by anionic acetate pillars through diatomic zinc nodes. The charge of the anionic framework is neutralized by the 1D arrays of $${{rm{Zn}}}{({{rm{DMSO}}})}_{6}^{2+}$$ cations that fill every second 1D channel of the framework. It is demonstrated that the repeatable and scalable epitaxy allows square cuboids of this charge-transfer MOF to grow stepwise to sizes in the centimeter range. The continuous growth with no size limits can be attributed to the ionic nature of the anionic framework with cationic 1D molecular fillers. These findings pave the way for epitaxial growth of bulk crystals of MOFs. Bulk crystal growth of metal-organic frameworks remains a challenge. Here, a single crystal of a metal-organic framework is grown homoepitaxially in the centimeter range, assisted by the ionic nature of the anionic framework with cationic 1D molecular fillers.
{"title":"Host-guest charge transfer for scalable single crystal epitaxy of a metal-organic framework","authors":"Arthur Mantel, Berthold Stöger, Alexander Prado-Roller, Hidetsugu Shiozawa","doi":"10.1038/s43246-024-00657-3","DOIUrl":"10.1038/s43246-024-00657-3","url":null,"abstract":"Methods to grow large crystals provide the foundation for material science and technology. Here we demonstrate single crystal homoepitaxy of a metal-organic framework (MOF) built of zinc, acetate and terephthalate ions, that encapsulate arrays of octahedral zinc dimethyl sulfoxide (DMSO) complex cations within its one-dimensional (1D) channels. The three-dimensional framework is built of two-dimensional Zn-terephthalate square lattices interconnected by anionic acetate pillars through diatomic zinc nodes. The charge of the anionic framework is neutralized by the 1D arrays of $${{rm{Zn}}}{({{rm{DMSO}}})}_{6}^{2+}$$ cations that fill every second 1D channel of the framework. It is demonstrated that the repeatable and scalable epitaxy allows square cuboids of this charge-transfer MOF to grow stepwise to sizes in the centimeter range. The continuous growth with no size limits can be attributed to the ionic nature of the anionic framework with cationic 1D molecular fillers. These findings pave the way for epitaxial growth of bulk crystals of MOFs. Bulk crystal growth of metal-organic frameworks remains a challenge. Here, a single crystal of a metal-organic framework is grown homoepitaxially in the centimeter range, assisted by the ionic nature of the anionic framework with cationic 1D molecular fillers.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00657-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1038/s43246-024-00627-9
Hyemin Jung, Seunghyun Lee, Xiao Jin, Yifan Liu, Theodore. J. Ronningen, Christopher. H. Grein, John. P. R. David, Sanjay Krishna
The rising concentration of greenhouse gases, especially methane and carbon dioxide, is driving global temperature increases and exacerbating the climate crisis. Monitoring these gases requires detectors that operate in the extended short-wavelength infrared range (~2.4 µm), covering methane (1.65 µm) and carbon dioxide (2.05 µm) wavelengths. Here, we present a high-performance linear mode avalanche photodetector (APD) with an InGaAs/GaAsSb type-II superlattice absorber and an AlGaAsSb multiplier, matched to InP substrates. This APD achieves a room temperature gain of 178, an external quantum efficiency of 3560% at 2 µm, low excess noise (less than 2 at gains below 20), and a small temperature coefficient of breakdown (7.58 mV/K·µm). These results indicate that a manufacturable semiconductor material-based APD could significantly advance high-sensitivity receivers for greenhouse gas monitoring, potentially enabling their commercial production and widespread use. Photodetectors for monitoring greenhouse gas emissions must cover the extended short-wavelength infrared range. Here, antimonide-based materials on a InP substrate enable a high-performance avalanche photodiode with detectivity beyond 2 µm wavelength.
{"title":"Low excess noise and high quantum efficiency avalanche photodiodes for beyond 2 µm wavelength detection","authors":"Hyemin Jung, Seunghyun Lee, Xiao Jin, Yifan Liu, Theodore. J. Ronningen, Christopher. H. Grein, John. P. R. David, Sanjay Krishna","doi":"10.1038/s43246-024-00627-9","DOIUrl":"10.1038/s43246-024-00627-9","url":null,"abstract":"The rising concentration of greenhouse gases, especially methane and carbon dioxide, is driving global temperature increases and exacerbating the climate crisis. Monitoring these gases requires detectors that operate in the extended short-wavelength infrared range (~2.4 µm), covering methane (1.65 µm) and carbon dioxide (2.05 µm) wavelengths. Here, we present a high-performance linear mode avalanche photodetector (APD) with an InGaAs/GaAsSb type-II superlattice absorber and an AlGaAsSb multiplier, matched to InP substrates. This APD achieves a room temperature gain of 178, an external quantum efficiency of 3560% at 2 µm, low excess noise (less than 2 at gains below 20), and a small temperature coefficient of breakdown (7.58 mV/K·µm). These results indicate that a manufacturable semiconductor material-based APD could significantly advance high-sensitivity receivers for greenhouse gas monitoring, potentially enabling their commercial production and widespread use. Photodetectors for monitoring greenhouse gas emissions must cover the extended short-wavelength infrared range. Here, antimonide-based materials on a InP substrate enable a high-performance avalanche photodiode with detectivity beyond 2 µm wavelength.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00627-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1038/s43246-024-00643-9
Zexiong Qiu, Jiale Liu, Chuanzhou Han, Chaoyang Wang, Junwei Xiang, Ziwei Zheng, Minhao Xia, Yang Zhou, Anyi Mei, Hongwei Han
Hole-conductor-free printable mesoscopic perovskite solar cells (p-MPSCs) have attracted widespread attention for their low cost, up-scalability, and exceptional stability. However, the high defect density of perovskite and the absence of interfacial barrier layer between perovskite and carbon electrode cause profound open-circuit voltage (VOC) loss, which results in uncompetitive power conversion efficiency (PCE). Herein, an anion-cation synergy of decylammonium sulfate (DA2SO4) is utilized for suppressing VOC loss of p-MPSCs via a facile post-treatment method. DA+ cations transform the perovskite adjacent to carbon electrode into wide-bandgap 2D perovskite for blocking electrons, while the SO42− anions interact with undercoordinated lead centers for reducing defect density. As a result, the modified device delivers an enhanced PCE from 17.78% to 19.59%, with an improved VOC from 0.98 V to 1.06 V. Meanwhile, the modified device without any encapsulation exhibits excellent moisture stability with the PCE remained almost 99% of the initial value after 528 h aging in 75% RH air at room temperature. Open-circuit voltage loss is an issue faced by hole-conductor-free printable mesoscopic perovskite solar cells. Here, a facile decylammonium sulfate post-treatment reduces the voltage loss via an anion-cation synergy, and increases the power conversion efficiency from 17.8% to 19.6%.
{"title":"Decylammonium sulfate post-treatment for efficient hole-conductor-free printable perovskite solar cells with reduced voltage loss","authors":"Zexiong Qiu, Jiale Liu, Chuanzhou Han, Chaoyang Wang, Junwei Xiang, Ziwei Zheng, Minhao Xia, Yang Zhou, Anyi Mei, Hongwei Han","doi":"10.1038/s43246-024-00643-9","DOIUrl":"10.1038/s43246-024-00643-9","url":null,"abstract":"Hole-conductor-free printable mesoscopic perovskite solar cells (p-MPSCs) have attracted widespread attention for their low cost, up-scalability, and exceptional stability. However, the high defect density of perovskite and the absence of interfacial barrier layer between perovskite and carbon electrode cause profound open-circuit voltage (VOC) loss, which results in uncompetitive power conversion efficiency (PCE). Herein, an anion-cation synergy of decylammonium sulfate (DA2SO4) is utilized for suppressing VOC loss of p-MPSCs via a facile post-treatment method. DA+ cations transform the perovskite adjacent to carbon electrode into wide-bandgap 2D perovskite for blocking electrons, while the SO42− anions interact with undercoordinated lead centers for reducing defect density. As a result, the modified device delivers an enhanced PCE from 17.78% to 19.59%, with an improved VOC from 0.98 V to 1.06 V. Meanwhile, the modified device without any encapsulation exhibits excellent moisture stability with the PCE remained almost 99% of the initial value after 528 h aging in 75% RH air at room temperature. Open-circuit voltage loss is an issue faced by hole-conductor-free printable mesoscopic perovskite solar cells. Here, a facile decylammonium sulfate post-treatment reduces the voltage loss via an anion-cation synergy, and increases the power conversion efficiency from 17.8% to 19.6%.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00643-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1038/s43246-024-00650-w
Yury Gogotsi is a pioneer of the burgeoning field of 2D MXenes. Here he offers his insight on the history of MXene development, promising applications and what he is excited about.
{"title":"Discussing MXenes with Yury Gogotsi","authors":"","doi":"10.1038/s43246-024-00650-w","DOIUrl":"10.1038/s43246-024-00650-w","url":null,"abstract":"Yury Gogotsi is a pioneer of the burgeoning field of 2D MXenes. Here he offers his insight on the history of MXene development, promising applications and what he is excited about.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00650-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-08DOI: 10.1038/s43246-024-00649-3
Thies Jansen, Ekaterina Kochetkova, Anna Isaeva, Alexander Brinkman, Chuan Li
Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. In this work, we investigate the transport properties of the intrinsic magnetic topological insulator MnBi2Te4 (MBT). In normal transport measurements, we observe the presence of chiral edge channels, though with deviations from perfect quantization due to factors such as non-uniform thickness, domain structures, and the presence of quasi-helical edge states. Subsequently, we fabricate superconducting junctions using niobium leads on MBT exfoliated flakes, which show an onset of supercurrent with clear Josephson coupling. The interference patterns in the superconducting junctions reveal interesting asymmetries, suggesting changes in the magnetic ordering of the MBT flakes under small applied magnetic fields. Moreover, the modulation of the critical current by magnetic field reveals a SQUID-like pattern, suggesting the presence of supercurrent through the quasi-helical edge states. Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. Here, the intrinsic and Josephson junction transport properties of magnetic topological insulator MnBi2Te4 are investigated, revealing superconducting interference patterns that suggest the presence of supercurrent through quasi-helical edge states.
{"title":"Josephson coupling across magnetic topological insulator MnBi2Te4","authors":"Thies Jansen, Ekaterina Kochetkova, Anna Isaeva, Alexander Brinkman, Chuan Li","doi":"10.1038/s43246-024-00649-3","DOIUrl":"10.1038/s43246-024-00649-3","url":null,"abstract":"Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. In this work, we investigate the transport properties of the intrinsic magnetic topological insulator MnBi2Te4 (MBT). In normal transport measurements, we observe the presence of chiral edge channels, though with deviations from perfect quantization due to factors such as non-uniform thickness, domain structures, and the presence of quasi-helical edge states. Subsequently, we fabricate superconducting junctions using niobium leads on MBT exfoliated flakes, which show an onset of supercurrent with clear Josephson coupling. The interference patterns in the superconducting junctions reveal interesting asymmetries, suggesting changes in the magnetic ordering of the MBT flakes under small applied magnetic fields. Moreover, the modulation of the critical current by magnetic field reveals a SQUID-like pattern, suggesting the presence of supercurrent through the quasi-helical edge states. Topological superconductors hosting Majorana zero modes are of great interest for both fundamental physics and potential quantum computing applications. Here, the intrinsic and Josephson junction transport properties of magnetic topological insulator MnBi2Te4 are investigated, revealing superconducting interference patterns that suggest the presence of supercurrent through quasi-helical edge states.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00649-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Modulating unique microenvironment including both oxidation and metallic states on sub-nanocluster metal catalysts remains challenging, since designing heterogeneous catalysis within controllable oxidation state is necessary for achieving optimum performance. Here we construct stable sub-nano-Co clusters, which shows different microenvironment with the reported sub-nanocluster catalysts and reported Co-based catalysts. The coexistence of both ionic bonds of Co-O and metallic bonds of Co-Co shows features of multiple oxidation and metallic states, which changes the electronic orbital configuration of the individual Co atom in clusters. The specific microenvironment within low oxidation state and high electron density promotes combination of empty and filled host orbitals to yield high electron transfer between metal and propane, which exhibits higher reactivity than the reported Co-based and other non-noble metals catalysts. The desired reactivity offers the possibility for the exploitation of highly efficient non-noble metal catalysts for propane dehydrogenation in industrial applications. Designing heterogeneous catalysts with modulated microenvironments is important for optimum performance. Here, cobalt sub-nanoclusters with Co-O and Co-Co bonds show multiple oxidation and metallic states for propane dehydrogenation.
在亚纳米簇金属催化剂上调节独特的微环境（包括氧化态和金属态）仍然具有挑战性，因为要实现最佳性能，必须在可控氧化态下设计异相催化。在这里，我们构建了稳定的亚纳米钴簇，它与已报道的亚纳米簇催化剂和已报道的钴基催化剂显示出不同的微环境。Co-O 的离子键和 Co-Co 的金属键共存，显示出多重氧化态和金属态的特征，从而改变了团簇中单个 Co 原子的电子轨道构型。低氧化态和高电子密度的特定微环境促进了空的和填充的主轨道的结合，从而在金属和丙烷之间产生高电子转移，与已报道的 Co 基催化剂和其他非贵金属催化剂相比，这种催化剂具有更高的反应活性。这种理想的反应活性为在工业应用中开发用于丙烷脱氢的高效非贵金属催化剂提供了可能。设计具有可调节微环境的异相催化剂对于实现最佳性能非常重要。在这里，具有 Co-O 和 Co-Co 键的钴亚纳米团簇在丙烷脱氢过程中表现出多种氧化态和金属态。
{"title":"Constructing matched sub-nanometric cobalt clusters with multiple oxidation and metallic states for efficient propane dehydrogenation","authors":"Weihua Deng, Dedong He, Dingkai Chen, Zijun Huang, Jiguang Deng, Yongming Luo","doi":"10.1038/s43246-024-00656-4","DOIUrl":"10.1038/s43246-024-00656-4","url":null,"abstract":"Modulating unique microenvironment including both oxidation and metallic states on sub-nanocluster metal catalysts remains challenging, since designing heterogeneous catalysis within controllable oxidation state is necessary for achieving optimum performance. Here we construct stable sub-nano-Co clusters, which shows different microenvironment with the reported sub-nanocluster catalysts and reported Co-based catalysts. The coexistence of both ionic bonds of Co-O and metallic bonds of Co-Co shows features of multiple oxidation and metallic states, which changes the electronic orbital configuration of the individual Co atom in clusters. The specific microenvironment within low oxidation state and high electron density promotes combination of empty and filled host orbitals to yield high electron transfer between metal and propane, which exhibits higher reactivity than the reported Co-based and other non-noble metals catalysts. The desired reactivity offers the possibility for the exploitation of highly efficient non-noble metal catalysts for propane dehydrogenation in industrial applications. Designing heterogeneous catalysts with modulated microenvironments is important for optimum performance. Here, cobalt sub-nanoclusters with Co-O and Co-Co bonds show multiple oxidation and metallic states for propane dehydrogenation.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00656-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-06DOI: 10.1038/s43246-024-00651-9
Anureet Kaur, Meet M. Fefar, Thomas Griggs, Keizo Akutagawa, Biqiong Chen, James J. C. Busfield
Traditionally, sulfur-cured natural rubber compounds exhibit limited recyclability due to a significant drop in mechanical performance after reprocessing. Maintaining physical and chemical properties after recycling of a cross-linked polymer is an essential requirement for the global rubber industry to become more sustainable. Here, we demonstrate that tuning the curing process to favour a reversible cross-linked network based on disulfide and polysulfide bonds enables recyclability. We use a sulfur-based vulcanization system optimized with copper (II) methacrylate at concentrations of 2.47, 4.94, and 9.89 phr to control disulfide metathesis at low temperatures and enhance recyclability. Mechanical characterization identifies 2.47 phr as optimal for maintaining mechanical properties after initial moulding and full recovery after recycling. Additionally, we demonstrate that copper (II) methacrylate can be incorporated into existing rubber waste streams to promote recyclability. Cross-linked polymers must maintain physical and chemical properties after recycling to improve sustainability. Here, tuning the curing process to favour a reversible cross-linked network using disulfides and polysulfides bonds retains mechanical performance.
传统上，硫硫化天然橡胶化合物的可回收性有限，原因是再加工后机械性能显著下降。交联聚合物在回收后仍能保持物理和化学特性，是全球橡胶工业实现可持续发展的基本要求。在此，我们证明了调整硫化工艺，使其有利于基于二硫键和多硫键的可逆交联网络，从而实现可回收性。我们使用硫基硫化体系，优化甲基丙烯酸铜 (II)，浓度分别为 2.47、4.94 和 9.89 phr，以控制二硫化物在低温下的偏析，提高可回收性。机械特性分析表明，2.47 phr 的浓度最适合在初次成型后保持机械特性，并在回收后完全恢复机械特性。此外，我们还证明了甲基丙烯酸铜 (II) 可融入现有的橡胶废料流中，以提高可回收性。交联聚合物在回收后必须保持物理和化学特性，以提高可持续性。在此，我们调整了固化过程，以便利用二硫键和多硫键形成可逆交联网络，从而保持机械性能。
{"title":"Recyclable sulfur cured natural rubber with controlled disulfide metathesis","authors":"Anureet Kaur, Meet M. Fefar, Thomas Griggs, Keizo Akutagawa, Biqiong Chen, James J. C. Busfield","doi":"10.1038/s43246-024-00651-9","DOIUrl":"10.1038/s43246-024-00651-9","url":null,"abstract":"Traditionally, sulfur-cured natural rubber compounds exhibit limited recyclability due to a significant drop in mechanical performance after reprocessing. Maintaining physical and chemical properties after recycling of a cross-linked polymer is an essential requirement for the global rubber industry to become more sustainable. Here, we demonstrate that tuning the curing process to favour a reversible cross-linked network based on disulfide and polysulfide bonds enables recyclability. We use a sulfur-based vulcanization system optimized with copper (II) methacrylate at concentrations of 2.47, 4.94, and 9.89 phr to control disulfide metathesis at low temperatures and enhance recyclability. Mechanical characterization identifies 2.47 phr as optimal for maintaining mechanical properties after initial moulding and full recovery after recycling. Additionally, we demonstrate that copper (II) methacrylate can be incorporated into existing rubber waste streams to promote recyclability. Cross-linked polymers must maintain physical and chemical properties after recycling to improve sustainability. Here, tuning the curing process to favour a reversible cross-linked network using disulfides and polysulfides bonds retains mechanical performance.","PeriodicalId":10589,"journal":{"name":"Communications Materials","volume":null,"pages":null},"PeriodicalIF":7.5,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s43246-024-00651-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：