Strategies to improve the efficiency of piezoelectric catalysis have long focused on piezo-optical coupling and the construction of heterojunctions. However, it is a challenge to reinforce the performance of piezoelectric catalysis in a single material. Herein the built-in nanopores in single-crystal ZnO rods are employed to form stress to intensify the piezo-catalytic efficiency. The piezo-catalytic efficiency of ZnO rods with built-in nanopores (holey ZnO NRs) for degrading dyes was about 1.7 times that of ZnO rods without built-in nanopores (ZnO NRs). The X-ray diffraction and Raman peaks of holey ZnO NRs appeared blue-shifted in comparison to ZnO NRs, uncovering the existence of tensile stress in holey ZnO NRs. The piezoelectric coefficient d33 of holey ZnO NRs increased by 1.92 times, triggering the amplification of piezoelectric catalytic property. Additionally, the piezoelectric current, carrier lifetime, and diffusion length of holey ZnO NRs were larger than that of ZnO NRs, respectively. These factors all contribute to the enhanced piezoelectric catalytic efficiency of holey ZnO NRs. This work demonstrates that the method of induced stress with built-in nanopores is a promising strategy for improving the piezoelectric catalytic efficiency of single-crystal ZnO rods.
{"title":"Enhanced piezo-catalysis in ZnO rods with built-in nanopores","authors":"Ting Li, Wenjin Hu, Changxin Tang, Zihao Zhou, Zhiguo Wang, Longlong Shu","doi":"10.26599/jac.2023.9220819","DOIUrl":"https://doi.org/10.26599/jac.2023.9220819","url":null,"abstract":"Strategies to improve the efficiency of piezoelectric catalysis have long focused on piezo-optical coupling and the construction of heterojunctions. However, it is a challenge to reinforce the performance of piezoelectric catalysis in a single material. Herein the built-in nanopores in single-crystal ZnO rods are employed to form stress to intensify the piezo-catalytic efficiency. The piezo-catalytic efficiency of ZnO rods with built-in nanopores (holey ZnO NRs) for degrading dyes was about 1.7 times that of ZnO rods without built-in nanopores (ZnO NRs). The X-ray diffraction and Raman peaks of holey ZnO NRs appeared blue-shifted in comparison to ZnO NRs, uncovering the existence of tensile stress in holey ZnO NRs. The piezoelectric coefficient d<sub>33</sub> of holey ZnO NRs increased by 1.92 times, triggering the amplification of piezoelectric catalytic property. Additionally, the piezoelectric current, carrier lifetime, and diffusion length of holey ZnO NRs were larger than that of ZnO NRs, respectively. These factors all contribute to the enhanced piezoelectric catalytic efficiency of holey ZnO NRs. This work demonstrates that the method of induced stress with built-in nanopores is a promising strategy for improving the piezoelectric catalytic efficiency of single-crystal ZnO rods.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135708160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For the first time, the flash sintering (FS) of high-purity alumina at room temperature, which was previously considered unachievable due to its low electrical conductivity, was conducted herein. The electrical arc originating from surface flashover was harnessed to induce FS at room temperature and low air pressure. The successful FS of high-purity alumina was realized at 60 kPa under the arc constraint, resulting in a notable relative density of the alumina sample of 98.7%. The electric–thermal coupling between the arc and high-purity alumina sample during the arc-induced FS process was analyzed via the finite element simulation method. The results revealed the thermal and electrical effects of the arc on the sample, which ultimately enhance the electrical conductivity of the alumina sample. The formation of a conductive channel on the sample surface, a result of increased electrical conductivity, was the pivotal factor in achieving FS in high-purity alumina at room temperature. The arc constraint technique can be applied to numerous materials, such as ionic conductors, semiconductors, and even insulators, under room-temperature and low-air-pressure conditions.
{"title":"Flash sintering of high-purity alumina at room temperature","authors":"Yueji Li, Qingguo Chi, Ziyang Yan, Nianping Yan, Jinling Liu, Rongxia Huang, Xilin Wang","doi":"10.26599/jac.2023.9220816","DOIUrl":"https://doi.org/10.26599/jac.2023.9220816","url":null,"abstract":"For the first time, the flash sintering (FS) of high-purity alumina at room temperature, which was previously considered unachievable due to its low electrical conductivity, was conducted herein. The electrical arc originating from surface flashover was harnessed to induce FS at room temperature and low air pressure. The successful FS of high-purity alumina was realized at 60 kPa under the arc constraint, resulting in a notable relative density of the alumina sample of 98.7%. The electric–thermal coupling between the arc and high-purity alumina sample during the arc-induced FS process was analyzed via the finite element simulation method. The results revealed the thermal and electrical effects of the arc on the sample, which ultimately enhance the electrical conductivity of the alumina sample. The formation of a conductive channel on the sample surface, a result of increased electrical conductivity, was the pivotal factor in achieving FS in high-purity alumina at room temperature. The arc constraint technique can be applied to numerous materials, such as ionic conductors, semiconductors, and even insulators, under room-temperature and low-air-pressure conditions.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135606030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, PbZrO3 (PZO) films have become a favorable electric storage material due to the unique electric field-induced phase transition behavior, but the severe hysteresis effect leads to the low energy storage density and efficiency. In this work, inserting Al2O3 (AO) insulation nanolayers is proposed to tune the polarization behavior of flexible PZO films, anticipating the optimization of energy storage performances. The results show that the thickness of the AO nanolayers has a deep influence on the polarization behavior of PZO films, PZO/AO/PZO (PAP) sandwiched films with 8 nm-AO interlayer deliver relaxor ferroelectric-like polarization instead of antiferroelectric counterpart. To further utilize AO nanolayers as top/bottom layers, a linear-like polarization and highest breakdown strength are achieved in the AO/PZO/AO/PZO/AO (APAPA8) multilayer films, leading to both high discharged energy storage density of 35.2 J/cm3 and efficiency of 92.9%, as well as excellent fatigue and bending endurance, good temperature and frequency stability. The tunable polarization induced by growing AO nanolayers makes antiferroelectric PZO films have great potential to be used as the energy storage dielectrics.
{"title":"Tunable polarization-drived high energy storage performances in flexible PbZrO <sub>3</sub> films by growing Al <sub>2</sub>O <sub>3</sub> nanolayers","authors":"Chao Yin, Tiandong Zhang, Zhuangzhuang Shi, Bowen Zhang, Changhai Zhang, Qingguo Chi","doi":"10.26599/jac.2023.9220814","DOIUrl":"https://doi.org/10.26599/jac.2023.9220814","url":null,"abstract":"In recent years, PbZrO<sub>3</sub> (PZO) films have become a favorable electric storage material due to the unique electric field-induced phase transition behavior, but the severe hysteresis effect leads to the low energy storage density and efficiency. In this work, inserting Al<sub>2</sub>O<sub>3 </sub>(AO) insulation nanolayers is proposed to tune the polarization behavior of flexible PZO films, anticipating the optimization of energy storage performances. The results show that the thickness of the AO nanolayers has a deep influence on the polarization behavior of PZO films, PZO/AO/PZO (PAP) sandwiched films with 8 nm-AO interlayer deliver relaxor ferroelectric-like polarization instead of antiferroelectric counterpart. To further utilize AO nanolayers as top/bottom layers, a linear-like polarization and highest breakdown strength are achieved in the AO/PZO/AO/PZO/AO (APAPA8) multilayer films, leading to both high discharged energy storage density of 35.2 J/cm<sup>3</sup> and efficiency of 92.9%, as well as excellent fatigue and bending endurance, good temperature and frequency stability. The tunable polarization induced by growing AO nanolayers makes antiferroelectric PZO films have great potential to be used as the energy storage dielectrics.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135606188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Achieving an excellent energy storage performance, together with a high cycling reliability, is desirable for expanding the technological applications of ferroelectric dielectrics. However, in a well-crystallized ferroelectric material, the concomitant high polarizability and low polarization-saturation field have led to a square-shaped polarization-electric field loop, fatally impairing both recoverable energy density (Wrec) and efficiency (η). Nanocrystalline ferroelectric films with a macroscopically amorphous structure have shown an improved Wrec and η, but their much-lower polarizability demands an extremely high electric field to achieve such performances, which is undesirable from economical viewpoints. Here, we propose a strategy to boost the energy storage performances and stabilities of ferroelectric capacitors simultaneously by constructing a tri-layer film in which a well-crystallized ferroelectric layer was sandwiched by two pseudo-linear dielectric layers with a dominant amorphous structure. In sol-gel-derived BaTiO3/(Pb,La,Ca)TiO3/BaTiO3 (BTO/PLCT/BTO) tri-layer films, we show that the above design is realized via a rapid thermal annealing which fully crystallized the middle PLCT layer while left the top/bottom BTO cap layers in a poor crystallization status. This sandwiched structure is endowed with an enhanced maximum polarization while a small remnant one, and a much-delayed polarization saturation, which corresponds to a large Wrec~80 J/cm3 and a high η~86%. Furthermore, the film showed an outstanding cycling-stability: its Wrec and η remain essentially unchanged after 109 electric cycles (DW/W<4%, Dη/η<2%). These good energy storage characteristics have proved the effectiveness of our proposed strategy, paving a way for the utilization of sandwiched films in applications of electric power systems and advanced pulsed-discharge devices.
{"title":"Synergically improved energy storage performance and stability in sol&ndash;gel processed BaTiO <sub>3</sub>/(Pb,La,Ca)TiO <sub>3</sub>/BaTiO <sub>3</sub> tri-layer films with a crystalline engineered sandwich structure","authors":"Jinpeng Liu, Ying Wang, Hanfei Zhu, Hongyu Luo, Xiao Zhai, Yu Huan, Jing Yan, Kun Wang, Chao Liu, Hongbo Cheng, Jun Ouyang","doi":"10.26599/jac.2023.9220821","DOIUrl":"https://doi.org/10.26599/jac.2023.9220821","url":null,"abstract":"Achieving an excellent energy storage performance, together with a high cycling reliability, is desirable for expanding the technological applications of ferroelectric dielectrics. However, in a well-crystallized ferroelectric material, the concomitant high polarizability and low polarization-saturation field have led to a square-shaped polarization-electric field loop, fatally impairing both recoverable energy density (<em>W</em><sub>rec</sub>) and efficiency (<em>η</em>). Nanocrystalline ferroelectric films with a macroscopically amorphous structure have shown an improved <em>W</em><sub>rec</sub> and <em>η</em>, but their much-lower polarizability demands an extremely high electric field to achieve such performances, which is undesirable from economical viewpoints. Here, we propose a strategy to boost the energy storage performances and stabilities of ferroelectric capacitors simultaneously by constructing a tri-layer film in which a well-crystallized ferroelectric layer was sandwiched by two pseudo-linear dielectric layers with a dominant amorphous structure. In sol-gel-derived BaTiO<sub>3</sub>/(Pb,La,Ca)TiO<sub>3</sub>/BaTiO<sub>3</sub> (BTO/PLCT/BTO) tri-layer films, we show that the above design is realized via a rapid thermal annealing which fully crystallized the middle PLCT layer while left the top/bottom BTO cap layers in a poor crystallization status. This sandwiched structure is endowed with an enhanced maximum polarization while a small remnant one, and a much-delayed polarization saturation, which corresponds to a large <em>W</em><sub>rec</sub>~80 J/cm<sup>3</sup> and a high <em>η~</em>86%. Furthermore, the film showed an outstanding cycling-stability: its <em>W</em><sub>rec</sub> and <em>η </em>remain essentially unchanged after 10<sup>9</sup> electric cycles (D<em>W</em>/<em>W<</em>4%, D<em>η</em>/<em>η<</em>2%). These good energy storage characteristics have proved the effectiveness of our proposed strategy, paving a way for the utilization of sandwiched films in applications of electric power systems and advanced pulsed-discharge devices.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135849569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.26599/jac.2023.9220808
Yang Lyu, Zhihong Han, Guangdong Zhao, Yuan Cheng, Shanbao Zhou, Xinghong Zhang, Guiqing Chen, Wenbo Han
In this paper, a high-yield Hf-modified SiHfBOC ceramic precursor was developed, and a high-pressure assisted impregnation pyrolysis method was proposed to achieve the preparation of 3D PyC-Cf/SiHfBOC composites. This high-pressure assisted impregnation method significantly improves the impregnation filling effect of the precursor in and between fiber bundles compared to dozens of traditional impregnation cycles. After undergoing just 9 PIP cycles, the composites achieved a relative density of approximately 90% and a density of 1.64 g/cm3. The critical temperature difference of 3D PyC-Cf/SiHfBOC composites after the shock of RT-1000 °C is as high as 650 °C, which is twice that of the traditional ceramic material, showing good thermal shock resistance. Under the effect of Hf modification, a dense HfO2-SiO2 oxide layer (thickness 93μm) was formed in situ on the surface of the 3D PyC-Cf/SiHfBOC composites, effectively preventing further erosion of the composite matrix by high-temperature oxidation gas. Even in the ultra-high temperature oxygen-containing environment at 1800 °C, it still exhibits an excellent non-ablative result (with a linear ablation rate of 0.83×10-4 mm·s-1). This work not only enriches the basic research on lightweight ultra-high temperature ceramic composites converted from Hf ceramic precursors but also provides strong technical support for their application in ultra-high temperature non-ablative thermal protection materials for high-speed aircraft.
{"title":"Efficient fabrication of light C <sub>f</sub>/SiHfBOC composite with excellent thermal shock resistance and ultra-high temperature ablation up 1800 &deg;C","authors":"Yang Lyu, Zhihong Han, Guangdong Zhao, Yuan Cheng, Shanbao Zhou, Xinghong Zhang, Guiqing Chen, Wenbo Han","doi":"10.26599/jac.2023.9220808","DOIUrl":"https://doi.org/10.26599/jac.2023.9220808","url":null,"abstract":"In this paper, a high-yield Hf-modified SiHfBOC ceramic precursor was developed, and a high-pressure assisted impregnation pyrolysis method was proposed to achieve the preparation of 3D PyC-C<sub>f</sub>/SiHfBOC composites. This high-pressure assisted impregnation method significantly improves the impregnation filling effect of the precursor in and between fiber bundles compared to dozens of traditional impregnation cycles. After undergoing just 9 PIP cycles, the composites achieved a relative density of approximately 90% and a density of 1.64 g/cm<sup>3</sup>. The critical temperature difference of 3D PyC-C<sub>f</sub>/SiHfBOC composites after the shock of RT-1000 °C is as high as 650 °C, which is twice that of the traditional ceramic material, showing good thermal shock resistance. Under the effect of Hf modification, a dense HfO<sub>2</sub>-SiO<sub>2</sub> oxide layer (thickness 93μm) was formed in situ on the surface of the 3D PyC-C<sub>f</sub>/SiHfBOC composites, effectively preventing further erosion of the composite matrix by high-temperature oxidation gas. Even in the ultra-high temperature oxygen-containing environment at 1800 °C, it still exhibits an excellent non-ablative result (with a linear ablation rate of 0.83×10<sup>-4</sup> mm·s<sup>-1</sup>). This work not only enriches the basic research on lightweight ultra-high temperature ceramic composites converted from Hf ceramic precursors but also provides strong technical support for their application in ultra-high temperature non-ablative thermal protection materials for high-speed aircraft.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135387617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two-dimensional nanomaterials (2DNMs) have attracted significant research interest due to their outstanding structural properties, which include unique electrical nanostructures, large surface areas, and high surface reactivity. These adaptable materials have outstanding physicochemical characteristics, making them useful in a variety of applications such as gas-sensing, electronics, energy storage, and catalysis. Extensive research has been conducted in the pursuit of high-performance room-temperature (RT) gas sensors with good selectivity, high sensitivity, long-term stability, and rapid response/recovery kinetics. Metal oxides, transition metal chalcogenides, MXenes, graphene, phosphorene, and boron nitride have all been discovered as 2DNMs with strong potential for gas sensors. This review presents an in-depth analysis of current advances in 2DNM research. It includes synthetic techniques, structural stabilities, gas-sensing mechanisms, critical performance parameters, and factors influencing the gas-sensing capabilities of 2DNMs. Furthermore, the present study emphasizes structural engineering and optimization methodologies that improve gas-sensing performance. It also highlights current challenges and outlines future research directions in the domain of tailoring 2DNMs for advanced RT gas sensors. This systematically designed comprehensive review article aims to provide readers with profound insights into gas detection, thereby inspiring the generation of innovative ideas to develop cutting-edge 2DNMs-based gas sensors.
{"title":"Revisiting traditional and modern trends in versatile 2D nanomaterials: Synthetic strategies, structural stability, and gas-sensing fundamentals","authors":"Mobashar Hassan, Siwei Liu, Zhiping Liang, Shahid Hussain, Junlin Liu, Guiwu Liu, Guanjun Qiao","doi":"10.26599/jac.2023.9220810","DOIUrl":"https://doi.org/10.26599/jac.2023.9220810","url":null,"abstract":"Two-dimensional nanomaterials (2DNMs) have attracted significant research interest due to their outstanding structural properties, which include unique electrical nanostructures, large surface areas, and high surface reactivity. These adaptable materials have outstanding physicochemical characteristics, making them useful in a variety of applications such as gas-sensing, electronics, energy storage, and catalysis. Extensive research has been conducted in the pursuit of high-performance room-temperature (RT) gas sensors with good selectivity, high sensitivity, long-term stability, and rapid response/recovery kinetics. Metal oxides, transition metal chalcogenides, MXenes, graphene, phosphorene, and boron nitride have all been discovered as 2DNMs with strong potential for gas sensors. This review presents an in-depth analysis of current advances in 2DNM research. It includes synthetic techniques, structural stabilities, gas-sensing mechanisms, critical performance parameters, and factors influencing the gas-sensing capabilities of 2DNMs. Furthermore, the present study emphasizes structural engineering and optimization methodologies that improve gas-sensing performance. It also highlights current challenges and outlines future research directions in the domain of tailoring 2DNMs for advanced RT gas sensors. This systematically designed comprehensive review article aims to provide readers with profound insights into gas detection, thereby inspiring the generation of innovative ideas to develop cutting-edge 2DNMs-based gas sensors.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134995040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.26599/jac.2023.9220807
Liu Tang, Hongcheng Yang, Enzhu Li, Chaowei Zhong
{"title":"A novel Na <sub>1&minus; <em>x</em> </sub>K <em> <sub>x</sub> </em>TaO <sub>3</sub> perovskite microwave dielectric ceramic with high permittivity and high positive temperature coefficient","authors":"Liu Tang, Hongcheng Yang, Enzhu Li, Chaowei Zhong","doi":"10.26599/jac.2023.9220807","DOIUrl":"https://doi.org/10.26599/jac.2023.9220807","url":null,"abstract":"","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135298487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, high-entropy metal-carbides (HECs) have attracted significant attention due to their exceptional physical and chemical properties. The combination of the excellent performance exhibited by bulk HECs ceramics and the distinctive geometric characteristics has paved the way for the emergence of one-dimensional (1D) HECs as a novel material with unique development potential. Herein, we successfully fabricated a novel (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C nanowire derived via Fe-assisted single-sourced precursor pyrolysis. Prior to the synthesis of the nanowires, the composition and microstructure of (Ti, Zr, Hf, Nb, Ta)-containing precursor (PHECs) were analyzed, and divinylbenzene (DVB) was used to accelerate the conversion process of the precursor and contribute to the formation of HECs, which also provided partial carbon source for the nanowire growth. Additionally, multi-branched, single-branched and single-branched bending nanowires were synthesized by adjusting the ratio of PHECs to DVB. The obtained single-branched (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C nanowires possessed smooth surfaces with an average diameter of 130~150 nm and a length of several tens of micrometers, which were single-crystal structure and typically grew along [11(_)1] direction. And the growth of (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C nanowires was in agreement with top-type vapor-liquid-solid mechanism. This work not only successfully achieved the fabrication of HECs nanowires by a catalyst-assisted polymer pyrolysis, but also provided a comprehensive analysis of the factors affecting their yield and morphology, highlighting the potential application of these attractive nano-materials.
{"title":"Single-source precursor derived high-entropy metal-carbide nanowires: Microstructure and growth evolution","authors":"Junhao Zhao, Yulei Zhang, Hui Chen, Yanqin Fu, Qing Miao, Jiachen Meng, Jiachen Li","doi":"10.26599/jac.2023.9220806","DOIUrl":"https://doi.org/10.26599/jac.2023.9220806","url":null,"abstract":"In recent years, high-entropy metal-carbides (HECs) have attracted significant attention due to their exceptional physical and chemical properties. The combination of the excellent performance exhibited by bulk HECs ceramics and the distinctive geometric characteristics has paved the way for the emergence of one-dimensional (1D) HECs as a novel material with unique development potential. Herein, we successfully fabricated a novel (Ti<sub>0.2</sub>Zr<sub>0.2</sub>Hf<sub>0.2</sub>Nb<sub>0.2</sub>Ta<sub>0.2</sub>)C nanowire derived via Fe-assisted single-sourced precursor pyrolysis. Prior to the synthesis of the nanowires, the composition and microstructure of (Ti, Zr, Hf, Nb, Ta)-containing precursor (PHECs) were analyzed, and divinylbenzene (DVB) was used to accelerate the conversion process of the precursor and contribute to the formation of HECs, which also provided partial carbon source for the nanowire growth. Additionally, multi-branched, single-branched and single-branched bending nanowires were synthesized by adjusting the ratio of PHECs to DVB. The obtained single-branched (Ti<sub>0.2</sub>Zr<sub>0.2</sub>Hf<sub>0.2</sub>Nb<sub>0.2</sub>Ta<sub>0.2</sub>)C nanowires possessed smooth surfaces with an average diameter of 130~150 nm and a length of several tens of micrometers, which were single-crystal structure and typically grew along [11(_)1] direction. And the growth of (Ti<sub>0.2</sub>Zr<sub>0.2</sub>Hf<sub>0.2</sub>Nb<sub>0.2</sub>Ta<sub>0.2</sub>)C nanowires was in agreement with top-type vapor-liquid-solid mechanism. This work not only successfully achieved the fabrication of HECs nanowires by a catalyst-assisted polymer pyrolysis, but also provided a comprehensive analysis of the factors affecting their yield and morphology, highlighting the potential application of these attractive nano-materials.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135298251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.26599/jac.2023.9220809
Zezhong Yang, Song Zheng, Guoyu Xi, Tao Pang, Shaoxiong Wang, Qingying Ye, Bin Zhuang, Daqin Chen
Recently, high-performance color converters excitable by blue laser diode (LD) have been sprung up for projection display. However, thermal accumulation effect of color converters is a non-negligible problem under high-power LD irradiation. Herein, we developed a novel opto-functional composite (patterned CaAlSiN3: Eu2+ phosphor-in-glass film-Y3Al5O12: Ce3+ phosphor-in-glass film@Al2O3 plate with aluminum “heat sink”) via a thermal management methodology of combining “phosphor wheel” and “heat sink” for the lighting source of high-power laser projection display. This new composite design makes it effective to transport the generated thermal phonons away to reduce thermal ionization process, and to yield stable and high-quality white light with brightness of 4510 lm @ 43 W, luminous efficacy of 105 lm/W, correlated color temperature of 3541 K, and color rendering index of 80.0. Furthermore, the phosphor-in-glass film-converted laser projection system was also successfully designed, showing more vivid color effect than traditional LED-based projector. This work emphasizes the importance of thermal management upon high power laser irradiation, and hopefully facilitates the development of new LD-driven lighting source for high-power laser projection display.
{"title":"Patterned phosphor-in-glass films with efficient thermal management for high-power laser projection display","authors":"Zezhong Yang, Song Zheng, Guoyu Xi, Tao Pang, Shaoxiong Wang, Qingying Ye, Bin Zhuang, Daqin Chen","doi":"10.26599/jac.2023.9220809","DOIUrl":"https://doi.org/10.26599/jac.2023.9220809","url":null,"abstract":"Recently, high-performance color converters excitable by blue laser diode (LD) have been sprung up for projection display. However, thermal accumulation effect of color converters is a non-negligible problem under high-power LD irradiation. Herein, we developed a novel opto-functional composite (patterned CaAlSiN<sub>3</sub>: Eu<sup>2+</sup> phosphor-in-glass film-Y<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>: Ce<sup>3+</sup> phosphor-in-glass film@Al<sub>2</sub>O<sub>3</sub> plate with aluminum “heat sink”) via a thermal management methodology of combining “phosphor wheel” and “heat sink” for the lighting source of high-power laser projection display. This new composite design makes it effective to transport the generated thermal phonons away to reduce thermal ionization process, and to yield stable and high-quality white light with brightness of 4510 lm @ 43 W, luminous efficacy of 105 lm/W, correlated color temperature of 3541 K, and color rendering index of 80.0. Furthermore, the phosphor-in-glass film-converted laser projection system was also successfully designed, showing more vivid color effect than traditional LED-based projector. This work emphasizes the importance of thermal management upon high power laser irradiation, and hopefully facilitates the development of new LD-driven lighting source for high-power laser projection display.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135889566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-01DOI: 10.26599/jac.2023.9220764
Wei Li, Zhaoju Yu, Leonore Wiehl, Tianshu Jiang, Ying Zhan, Emmanuel III Ricohermoso, Martin Etter, Emanuel Ionescu, Qingbo Wen, Christian Lathe, Robert Farla, Dharma Teppala Teja, Sebastian Bruns, Marc Widenmeyer, Anke Weidenkaff, Leopoldo Molina-Luna, Ralf Riedel, Shrikant Bhat
Cubic silicon nitride (γ-Si3N4) is superhard and one of the hardest materials after diamond and cubic boron nitride (cBN), but has higher thermal stability in an oxidizing environment than diamond, making it a competitive candidate for technological applications in harsh conditions (e.g., drill head and abrasives). Here, we report the high-pressure synthesis and characterization of the structural and mechanical properties of a γ-Si3N4/Hf3N4 ceramic nanocomposite derived from single-phase amorphous Si-Hf-N precursor. The synthesis of the γ-Si3N4/Hf3N4nanocomposite is performed at ~20 GPa and ca. 1500 °C in a large volume multi anvil press. The structural evolution of the amorphous precursor and its crystallization to γ-Si3N4/Hf3N4 nanocomposites under high pressure is assessed by in situ synchrotron energy-dispersive X-ray diffraction measurements at ~19.5 GPa in the temperature range from ca. 1000-1900 °C. The fracture toughness of the two-phase nanocomposite amounts ~6/6.9 MPa·m1/2 and is about 2 times that of single-phase γ-Si3N4, while its hardness of ca. 30 GPa remains high. This work provides a reliable and feasible route for the synthesis of advanced hard and tough γ-Si3N4-based nanocomposites with excellent thermal stabililty.
{"title":"Hard and tough novel high-pressure <i>γ</i>-Si <sub>3</sub>N <sub>4</sub>/Hf <sub>3</sub>N <sub>4</sub> ceramic nanocomposites","authors":"Wei Li, Zhaoju Yu, Leonore Wiehl, Tianshu Jiang, Ying Zhan, Emmanuel III Ricohermoso, Martin Etter, Emanuel Ionescu, Qingbo Wen, Christian Lathe, Robert Farla, Dharma Teppala Teja, Sebastian Bruns, Marc Widenmeyer, Anke Weidenkaff, Leopoldo Molina-Luna, Ralf Riedel, Shrikant Bhat","doi":"10.26599/jac.2023.9220764","DOIUrl":"https://doi.org/10.26599/jac.2023.9220764","url":null,"abstract":"Cubic silicon nitride (γ-Si<sub>3</sub>N<sub>4</sub>) is superhard and one of the hardest materials after diamond and cubic boron nitride (cBN), but has higher thermal stability in an oxidizing environment than diamond, making it a competitive candidate for technological applications in harsh conditions (e.g., drill head and abrasives). Here, we report the high-pressure synthesis and characterization of the structural and mechanical properties of a γ-Si<sub>3</sub>N<sub>4</sub>/Hf<sub>3</sub>N<sub>4</sub> ceramic nanocomposite derived from single-phase amorphous Si-Hf-N precursor. The synthesis of the γ-Si<sub>3</sub>N<sub>4</sub>/Hf<sub>3</sub>N<sub>4</sub><sub> </sub>nanocomposite is performed at ~20 GPa and ca. 1500 °C in a large volume multi anvil press. The structural evolution of the amorphous precursor and its crystallization to γ-Si<sub>3</sub>N<sub>4</sub>/Hf<sub>3</sub>N<sub>4</sub> nanocomposites under high pressure is assessed by <em>in situ</em> synchrotron energy-dispersive X-ray diffraction measurements at ~19.5 GPa in the temperature range from ca. 1000-1900 °C. The fracture toughness of the two-phase nanocomposite amounts ~6/6.9 MPa·m<sup>1/2</sup> and is about 2 times that of single-phase γ-Si<sub>3</sub>N<sub>4</sub>, while its hardness of ca. 30 GPa remains high. This work provides a reliable and feasible route for the synthesis of advanced hard and tough γ-Si<sub>3</sub>N<sub>4</sub>-based nanocomposites with excellent thermal stabililty.","PeriodicalId":14862,"journal":{"name":"Journal of Advanced Ceramics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136185122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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