Pub Date : 2024-11-22DOI: 10.1016/j.jallcom.2024.177720
Hao Jiang, Yanqiang Qiao, Xiping Guo, Xiao Ma, Xi Nan
This study aims to improve the coating density by introducing Al2O3-SiO2 film as a diffusion barrier (DB) at the interface during the sintering process. The influence of the thickness of DB at the interface on the density, phase constituent and interface structure of the coating was studied. The results showed that the Al2O3-SiO2 film can effectively reduce the inward diffusion of Si, facilitating the densification of MoSi2 coating. Increasing the thickness of the DB correspondingly improves the diffusion blocking effect. Compared with the MoSi2 coating without DB, the area porosity of the coating with a 5 μm thick DB decreased from 26.8% to 15.8%. The oxide DB is discontinuously distributed at the interface. However, although the density of the coatings was markedly increased, severe cracking occurred when the diffusion barrier was excessively thick. The microstructure of coating without DB and coatings with 3 and 5 μm thick DB is generally similar, with the inter-diffusion zone (IDZ) consisting of Mo5Si3, Nb4Fe3Si5, and (Nb,X)5Si3 three layers. In contrast, the IDZ of coatings with 10 and 15 μm thick DB is comprised of a single (Nb,X)5Si3 layer. In comparison to the MoSi₂ coating without DB, the coating with a 5 μm thick DB exhibited a markedly enhanced oxidation resistance. The pores in the coating can be quickly filled by the as-formed SiO2. The weight gain of coating with a 5 μm thick DB is about 9.4 mg/cm² after oxidation at 1250 °C for 100 h, and about 10.1 mg/cm² after oxidation at 1350 °C for 50 h.
本研究旨在通过在烧结过程中在界面上引入 Al2O3-SiO2 薄膜作为扩散屏障（DB）来提高涂层密度。研究了界面处扩散阻挡层厚度对涂层密度、相组成和界面结构的影响。结果表明，Al2O3-SiO2 膜能有效减少硅的向内扩散，促进 MoSi2 涂层的致密化。增加 DB 的厚度可相应地提高扩散阻断效果。与无 DB 的 MoSi2 涂层相比，5 μm 厚 DB 涂层的面积孔隙率从 26.8% 降至 15.8%。氧化物 DB 在界面上呈不连续分布。然而，虽然涂层的密度明显增加，但当扩散屏障过厚时，还是出现了严重的裂纹。不含 DB 的涂层和含 3 和 5 μm 厚 DB 的涂层的微观结构基本相似，扩散间区（IDZ）由 Mo5Si3、Nb4Fe3Si5 和 (Nb,X)5Si3 三层组成。相比之下，厚度为 10 和 15 μm 的 DB 涂层的 IDZ 由单层 (Nb,X)5Si3 组成。与不含 DB 的 MoSi₂ 涂层相比，含 5 μm 厚 DB 的涂层的抗氧化性明显增强。涂层中的孔隙可以很快被形成的二氧化硅填满。带有 5 μm 厚 DB 的涂层在 1250 °C 下氧化 100 小时后的增重约为 9.4 mg/cm²，在 1350 °C 下氧化 50 小时后的增重约为 10.1 mg/cm²。
{"title":"Effect of Al2O3-SiO2 film at the interface on the microstructure formation and oxidation resistance of MoSi2 coating on Nb-Si based alloy via slurry sintering method","authors":"Hao Jiang, Yanqiang Qiao, Xiping Guo, Xiao Ma, Xi Nan","doi":"10.1016/j.jallcom.2024.177720","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177720","url":null,"abstract":"This study aims to improve the coating density by introducing Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> film as a diffusion barrier (DB) at the interface during the sintering process. The influence of the thickness of DB at the interface on the density, phase constituent and interface structure of the coating was studied. The results showed that the Al<sub>2</sub>O<sub>3</sub>-SiO<sub>2</sub> film can effectively reduce the inward diffusion of Si, facilitating the densification of MoSi<sub>2</sub> coating. Increasing the thickness of the DB correspondingly improves the diffusion blocking effect. Compared with the MoSi<sub>2</sub> coating without DB, the area porosity of the coating with a 5 μm thick DB decreased from 26.8% to 15.8%. The oxide DB is discontinuously distributed at the interface. However, although the density of the coatings was markedly increased, severe cracking occurred when the diffusion barrier was excessively thick. The microstructure of coating without DB and coatings with 3 and 5 μm thick DB is generally similar, with the inter-diffusion zone (IDZ) consisting of Mo<sub>5</sub>Si<sub>3</sub>, Nb<sub>4</sub>Fe<sub>3</sub>Si<sub>5</sub>, and (Nb,X)<sub>5</sub>Si<sub>3</sub> three layers. In contrast, the IDZ of coatings with 10 and 15 μm thick DB is comprised of a single (Nb,X)<sub>5</sub>Si<sub>3</sub> layer. In comparison to the MoSi₂ coating without DB, the coating with a 5 μm thick DB exhibited a markedly enhanced oxidation resistance. The pores in the coating can be quickly filled by the as-formed SiO<sub>2</sub>. The weight gain of coating with a 5 μm thick DB is about 9.4 mg/cm² after oxidation at 1250 °C for 100 h, and about 10.1 mg/cm² after oxidation at 1350 °C for 50 h.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"76 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-22DOI: 10.1016/j.jallcom.2024.177700
Peter Benard Oboso, Seiya Oyama, Julia Horioka, Li-Fu Yi, Tetsuhiko Onda, Shigekazu Morito, Zhong-Chun Chen
In this study, two novel Co-free medium entropy alloys (MEAs) with compositions of Cu20Cr10Fe35Ni35 (Cu20) and Cu10Cr20Fe35Ni35 (Cu10) were successfully prepared by a combination of mechanical alloying (MA) and spark plasma sintering (SPS). The Cu20 alloy exhibited a heterogeneous microstructure consisting of coarse and ultrafine grains (UFG) with a face-centered cubic (FCC) structure. In contrast, the Cu10 alloy showed a homogeneous UFG microstructure with an FCC matrix and a small amount of BCC phase. Moreover, both alloys contained a small amount of Cr7C3 particles, introduced by milling media during MA. In comparison with the Cu20 alloy, the Cu10 alloy exhibited better tensile properties, e.g., yield strength of 712 MPa, ultimate tensile strength of 843 MPa, and elongation of 20.1%, demonstrating an excellent balance between strength and ductility compared to some well-established FCC-structured multi-component MEAs and high entropy alloys (HEAs). The enhanced tensile properties of the Cu10 alloy are attributed to the synergistic effects of grain refinement and Orowan strengthening by the fine Cr7C3 particles. The findings of this work provide valuable insights for designing cost-effective HEAs and MEAs with high strength and desirable ductility for various structural applications.
本研究采用机械合金化（MA）和火花等离子烧结（SPS）相结合的方法，成功制备了两种新型无钴中熵合金（MEA），其成分分别为 Cu20Cr10Fe35Ni35（Cu20）和 Cu10Cr20Fe35Ni35（Cu10）。Cu20 合金呈现出由粗晶粒和超细晶粒（UFG）组成的异质微观结构，具有面心立方（FCC）结构。相比之下，Cu10 合金呈现出均匀的 UFG 显微结构，基体为 FCC，并含有少量 BCC 相。此外，这两种合金都含有少量的 Cr7C3 颗粒，这些颗粒是在 MA 过程中通过研磨介质引入的。与 Cu20 合金相比，Cu10 合金具有更好的拉伸性能，例如屈服强度为 712 兆帕，极限拉伸强度为 843 兆帕，伸长率为 20.1%，与一些成熟的 FCC 结构多组分 MEA 和高熵合金 (HEA) 相比，Cu10 合金在强度和延展性之间实现了极佳的平衡。Cu10 合金拉伸性能的增强归因于细小 Cr7C3 颗粒的晶粒细化和奥罗旺强化的协同效应。这项工作的发现为设计具有高强度和理想延展性的高成本效益 HEA 和 MEA 提供了宝贵的见解，可用于各种结构应用。
{"title":"Microstructure and mechanical properties of CuCrFeNi medium entropy alloys synthesized via mechanical alloying and spark plasma sintering","authors":"Peter Benard Oboso, Seiya Oyama, Julia Horioka, Li-Fu Yi, Tetsuhiko Onda, Shigekazu Morito, Zhong-Chun Chen","doi":"10.1016/j.jallcom.2024.177700","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177700","url":null,"abstract":"In this study, two novel Co-free medium entropy alloys (MEAs) with compositions of Cu<sub>20</sub>Cr<sub>10</sub>Fe<sub>35</sub>Ni<sub>35</sub> (Cu20) and Cu<sub>10</sub>Cr<sub>20</sub>Fe<sub>35</sub>Ni<sub>35</sub> (Cu10) were successfully prepared by a combination of mechanical alloying (MA) and spark plasma sintering (SPS). The Cu20 alloy exhibited a heterogeneous microstructure consisting of coarse and ultrafine grains (UFG) with a face-centered cubic (FCC) structure. In contrast, the Cu10 alloy showed a homogeneous UFG microstructure with an FCC matrix and a small amount of BCC phase. Moreover, both alloys contained a small amount of Cr<sub>7</sub>C<sub>3</sub> particles, introduced by milling media during MA. In comparison with the Cu20 alloy, the Cu10 alloy exhibited better tensile properties, <em>e.g.</em>, yield strength of 712<!-- --> <!-- -->MPa, ultimate tensile strength of 843<!-- --> <!-- -->MPa, and elongation of 20.1%, demonstrating an excellent balance between strength and ductility compared to some well-established FCC-structured multi-component MEAs and high entropy alloys (HEAs). The enhanced tensile properties of the Cu10 alloy are attributed to the synergistic effects of grain refinement and Orowan strengthening by the fine Cr<sub>7</sub>C<sub>3</sub> particles. The findings of this work provide valuable insights for designing cost-effective HEAs and MEAs with high strength and desirable ductility for various structural applications.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"1 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-22DOI: 10.1016/j.jallcom.2024.177706
Ping Zhang, Xiujie Yue, Yajie Sun, Hanping Zhou, Youqiang Wang
This study employs an orthogonal experimental framework to investigate the effects of ultrasonic peening and solid projectile with water jet (UIT-SPEWJ) as a hybrid surface enhancement method on the surface integrity of 7075-T6 aluminum alloy. The research delves into the impact of various processing parameters on the alloy’s surface characteristics, encompassing surface finish, microhardness, residual stresses, and microstructural alterations. Our findings reveal a variation in surface roughness post-treatment, ranging from 0.852 to 2.411 μm; When the jet pressure was 25 MPa, the jet target distance was 7.5 mm, and the ultrasonic amplitude was 5 μm (referred to as UIT-SPEWJ-6), the surface roughness was the lowest at 0.852 μm. In contrast, when the jet pressure was 20 MPa, the jet target distance was 12.5 mm, and the ultrasonic amplitude was 20 μm (referred to as UIT-SPEWJ-4), the surface roughness was the highest at 2.411 μm. Surface textures displayed notable features such as crater-like indentations, adhered debris, and microporosity. The microhardness values on the treated surfaces were measured between 180 and 240 HV, marking an enhancement of 2.2% to 36.3% over the untreated samples. Among the specimens, UIT-SPEWJ-6 exhibited the deepest hardening effect with a layer reaching 240 μm, whereas UIT-SPEWJ-4 showed the shallowest at approximately 210 μm. Residual compressive stresses were observed to lie between 277 and 530 MPa, which denotes a substantial increase of 394.6% to 846.4% over the baseline stress of 56 MPa in untreated samples. Morphologically, UIT-SPEWJ-4 displayed continuous precipitate-free zones (PFZs) measuring 11 to 23 nm and abundant precipitates within 42 to 61 nm accompanied by pronounced dislocation activity. In contrast, UIT-SPEWJ-6 revealed discontinuous PFZs ranging from 7 to 16 nm, smaller precipitates between 22 and 36 nm, refined grain structures, and a higher dislocation density.
{"title":"Ultrasonic Peening-Water Jet combined Surface Modification Mechanism and Surface Integrity Study of 7075 Aluminum Alloy","authors":"Ping Zhang, Xiujie Yue, Yajie Sun, Hanping Zhou, Youqiang Wang","doi":"10.1016/j.jallcom.2024.177706","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177706","url":null,"abstract":"This study employs an orthogonal experimental framework to investigate the effects of ultrasonic peening and solid projectile with water jet (UIT-SPEWJ) as a hybrid surface enhancement method on the surface integrity of 7075-T6 aluminum alloy. The research delves into the impact of various processing parameters on the alloy’s surface characteristics, encompassing surface finish, microhardness, residual stresses, and microstructural alterations. Our findings reveal a variation in surface roughness post-treatment, ranging from 0.852 to 2.411 μm; When the jet pressure was 25<!-- --> <!-- -->MPa, the jet target distance was 7.5<!-- --> <!-- -->mm, and the ultrasonic amplitude was 5 μm (referred to as UIT-SPEWJ-6), the surface roughness was the lowest at 0.852 μm. In contrast, when the jet pressure was 20<!-- --> <!-- -->MPa, the jet target distance was 12.5<!-- --> <!-- -->mm, and the ultrasonic amplitude was 20 μm (referred to as UIT-SPEWJ-4), the surface roughness was the highest at 2.411 μm. Surface textures displayed notable features such as crater-like indentations, adhered debris, and microporosity. The microhardness values on the treated surfaces were measured between 180 and 240 HV, marking an enhancement of 2.2% to 36.3% over the untreated samples. Among the specimens, UIT-SPEWJ-6 exhibited the deepest hardening effect with a layer reaching 240 μm, whereas UIT-SPEWJ-4 showed the shallowest at approximately 210 μm. Residual compressive stresses were observed to lie between 277 and 530<!-- --> <!-- -->MPa, which denotes a substantial increase of 394.6% to 846.4% over the baseline stress of 56<!-- --> <!-- -->MPa in untreated samples. Morphologically, UIT-SPEWJ-4 displayed continuous precipitate-free zones (PFZs) measuring 11 to 23<!-- --> <!-- -->nm and abundant precipitates within 42 to 61<!-- --> <!-- -->nm accompanied by pronounced dislocation activity. In contrast, UIT-SPEWJ-6 revealed discontinuous PFZs ranging from 7 to 16<!-- --> <!-- -->nm, smaller precipitates between 22 and 36<!-- --> <!-- -->nm, refined grain structures, and a higher dislocation density.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"188 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-22DOI: 10.1016/j.jallcom.2024.177714
Muhammad Nauman Tahir, Gui Yang, Yang Wu, Juan Long, Dan Xiong, Xiaomin Ren, Bin Huang, Xuejun Pan
The Fluorite-type Bi4MoO9 nanocrystals with well-defined octahedral shape were successfully synthesized via a facile hydrothermal route. The structural transformation from the Aurivillius-type Bi2MoO6 nanocrystals to the Fluorite-related nanocrystals (Bi4MoO9) can be efficiently and precisely controlled by regulating the pH value of the reaction. The influences of reaction time and temperature were investigated to gain a deep understanding of the formation process of octahedral-shaped Bi4MoO9. Furthermore, the photocatalytic activity results showed that the octahedral Bi4MoO9 single crystals manifested excellent photocatalytic activities for the degradation of tetracycline (TC), rhodamine B (RhB), and bisphenol A (BPA). Additionally, the possible degradation intermediates of TC were unraveled and the ecotoxicity changes of identified TC intermediates were evaluated in detail. This present study develops a novel morphology structure of Bi4MoO9 and highlights its promise in the field of environmental remediation.
{"title":"Controllable fabrication of Fluorite-type Bi4MoO9 nanocrystals with well-defined octahedral shape for visible-light photocatalytic degradation","authors":"Muhammad Nauman Tahir, Gui Yang, Yang Wu, Juan Long, Dan Xiong, Xiaomin Ren, Bin Huang, Xuejun Pan","doi":"10.1016/j.jallcom.2024.177714","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177714","url":null,"abstract":"The Fluorite-type Bi<sub>4</sub>MoO<sub>9</sub> nanocrystals with well-defined octahedral shape were successfully synthesized via a facile hydrothermal route. The structural transformation from the Aurivillius-type Bi<sub>2</sub>MoO<sub>6</sub> nanocrystals to the Fluorite-related nanocrystals (Bi<sub>4</sub>MoO<sub>9</sub>) can be efficiently and precisely controlled by regulating the pH value of the reaction. The influences of reaction time and temperature were investigated to gain a deep understanding of the formation process of octahedral-shaped Bi<sub>4</sub>MoO<sub>9</sub>. Furthermore, the photocatalytic activity results showed that the octahedral Bi<sub>4</sub>MoO<sub>9</sub> single crystals manifested excellent photocatalytic activities for the degradation of tetracycline (TC), rhodamine B (RhB), and bisphenol A (BPA). Additionally, the possible degradation intermediates of TC were unraveled and the ecotoxicity changes of identified TC intermediates were evaluated in detail. This present study develops a novel morphology structure of Bi<sub>4</sub>MoO<sub>9</sub> and highlights its promise in the field of environmental remediation.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"15 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-22DOI: 10.1016/j.jallcom.2024.177715
Ali Akhtar, Shama Sadaf, Rujun Zhou, Qiang Ling, Si Luo, Mingming Han, Wu Di, Jianqiao Liu, Daru Chen, Xiangfeng Chu
Designing novel acetic acid gas sensors is highly imperative for human health. Two-dimensional (2D) layered MXene Ti3C2Tx is becoming an emerging and promising material in gas sensing. In this manuscript, the hydrothermal method was used to synthesize MXenes Ti3C2Tx/Nb2CTx supported NiCo2O4-MnO2 composites and pure materials. The structure, chemical composition and morphology of the samples were studied by SEM, EDS, TEM, HRTEM, XRD, BET, FTIR, UV-visible, XPS and Raman, justifying the successful synthesis of products. The layered structure of Ti3C2Tx enhanced the BET surface area and provided sufficient sites, which assisted the gas sensing improvement. The gas sensors were fabricated from synthesized products and were tested for different kinds of VOCs deeply. The results exposed that the gas sensor of Ti3C2Tx-NiCo2O4-MnO2 (5% of Ti3C2Tx=NCO-Mn-Ti-5) was highly sensitive to 20 ppm acetic acid and very less responsive to all other VOCs (acetone, TMA, ethanol, methanol, formaldehyde, acetaldehyde, acetylene and xylene) at room temperature. The response (Rg/Ra) to 20 ppm acetic acid was 12.5 and the lowest detection limit was 0.05 ppm. Additionally, the sensor of NCO-Mn-Ti-5 revealed great stability/reproducibility, short response/recovery times and linearity between acetic acid concentration and response. The idea of the novel sensor (NCO-Mn-Ti-5) could be potentially useful in the field of sensors.
{"title":"Highly responsive and stable room temperature acetic acid gas sensor based on nano-composite of MXene Ti3C2TX-NiCo2O4-MnO2","authors":"Ali Akhtar, Shama Sadaf, Rujun Zhou, Qiang Ling, Si Luo, Mingming Han, Wu Di, Jianqiao Liu, Daru Chen, Xiangfeng Chu","doi":"10.1016/j.jallcom.2024.177715","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177715","url":null,"abstract":"Designing novel acetic acid gas sensors is highly imperative for human health. Two-dimensional (2D) layered MXene Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> is becoming an emerging and promising material in gas sensing. In this manuscript, the hydrothermal method was used to synthesize MXenes Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>/Nb<sub>2</sub>CT<sub>x</sub> supported NiCo<sub>2</sub>O<sub>4</sub>-MnO<sub>2</sub> composites and pure materials. The structure, chemical composition and morphology of the samples were studied by SEM, EDS, TEM, HRTEM, XRD, BET, FTIR, UV-visible, XPS and Raman, justifying the successful synthesis of products. The layered structure of Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> enhanced the BET surface area and provided sufficient sites, which assisted the gas sensing improvement. The gas sensors were fabricated from synthesized products and were tested for different kinds of VOCs deeply. The results exposed that the gas sensor of Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>-NiCo<sub>2</sub>O<sub>4</sub>-MnO<sub>2</sub> (5% of Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub>=NCO-Mn-Ti-5) was highly sensitive to 20 ppm acetic acid and very less responsive to all other VOCs (acetone, TMA, ethanol, methanol, formaldehyde, acetaldehyde, acetylene and xylene) at room temperature. The response (R<sub>g</sub>/R<sub>a</sub>) to 20 ppm acetic acid was 12.5 and the lowest detection limit was 0.05 ppm. Additionally, the sensor of NCO-Mn-Ti-5 revealed great stability/reproducibility, short response/recovery times and linearity between acetic acid concentration and response. The idea of the novel sensor (NCO-Mn-Ti-5) could be potentially useful in the field of sensors.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"38 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Designing and fabricating flexible piezoresistive pressure sensors (FPPS) with simultaneous high sensitivity and a broad linear working region remains a considerable challenge. In this work, thermoplastic polyurethane (TPU) fiber films were first prepared via electrospinning. Then, the CNTs were anchored onto the surface of a TPU fiber films via ultrasonication as the driving force. Finally, polydimethylsiloxane (PDMS) was used to modify the CNT/TPU and obtain the PDMS/CNT/TPU composite materials. The electrical and mechanical properties of CNT/TPU and PDMS/CNT/TPU were studied. The sensor performances of FPPS based on CNT/TPU and PDMS/CNT/TPU were analyzed and compared. These results prove that the sensitivity of FPPS is significantly improved after the PDMS modification. The optimized PDMS/CNT/TPU FPPS has a sensitivity of 1.43 kPa-1 in a ultra-broad linear working region of 0-2500 kPa and cycling stability over 6000 cycles. FPPS has been successfully used to monitor physiological signals and human movements, which indicates great potential for wearable electronics and human-machine interfaces.
{"title":"High-sensitivity and ultra-broad linear working region flexible piezoresistive pressure sensors based on PDMS/CNT/TPU","authors":"Zhiwen Chen, Jingchen Ma, Xiaoyu Zhang, Aixiang Wei, Ningqi Luo, Yuding He, Yu Zhao, Zhen Liu, Jiaxiong Xu","doi":"10.1016/j.jallcom.2024.177711","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177711","url":null,"abstract":"Designing and fabricating flexible piezoresistive pressure sensors (FPPS) with simultaneous high sensitivity and a broad linear working region remains a considerable challenge. In this work, thermoplastic polyurethane (TPU) fiber films were first prepared via electrospinning. Then, the CNTs were anchored onto the surface of a TPU fiber films via ultrasonication as the driving force. Finally, polydimethylsiloxane (PDMS) was used to modify the CNT/TPU and obtain the PDMS/CNT/TPU composite materials. The electrical and mechanical properties of CNT/TPU and PDMS/CNT/TPU were studied. The sensor performances of FPPS based on CNT/TPU and PDMS/CNT/TPU were analyzed and compared. These results prove that the sensitivity of FPPS is significantly improved after the PDMS modification. The optimized PDMS/CNT/TPU FPPS has a sensitivity of 1.43 kPa<sup>-1</sup> in a ultra-broad linear working region of 0-2500 kPa and cycling stability over 6000 cycles. FPPS has been successfully used to monitor physiological signals and human movements, which indicates great potential for wearable electronics and human-machine interfaces.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"16 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cu2BaSn(S,Se)4 is gaining tremendous attention as a potential absorber due to its non-toxicity, earth abundance, and low antisite defects opposing Cu2ZnSn(S,Se)4. However, the highest experimental efficiency of 6.17% is achieved with the device structure Al:ZnO/Mg:ZnO/Zn1-xCdxS/Cu2BaSn(S,Se)4/Mo where the drawback is large open circuit voltage (VOC) loss stemming from the large cliff at the absorber/buffer interface and back contact recombination. Therefore, finding a suitable non-toxic buffer with modification of the bottom stack is crucial. In this regard, Cu2BaSn(S,Se)4 solar cells based on diverse buffers are numerically simulated using SCAPS-1D with Ni as back contact and introducing back surface field (BSF) at the absorber/Ni interface. At first, a baseline model validating the experimental efficiency is designed. The application of Ni enhanced efficiency to 7.92% due to the formation of ohmic contact. Further, it is improved to 9.91% with anti-reflection coating. Afterward, a total of 780 solar cells were designed with six buffer and eight BSF combinations by optimizing the absorber, buffer, and interface properties where the highest efficiency of 28.11% with incredible fill factor (90%) and less VOC loss (0.24 V) is accomplished for the AZO/ZMO/TiO2/Cu2BaSn(S,Se)4/CuI/Ni solar cell. Further, the importance of BSF is analyzed via energy band diagrams, Mott-Schottky and Nyquist plots. The outcomes disclosed that the BSF greatly influences the energy band alignment, built-in potential, depletion width, and recombination resistance of solar cells, underscoring its significance in improving performance. Overall, the present work proposes an efficient strategy to modify the device configuration of Cu2BaSn(S,Se)4 solar cells to enhance their efficiency.
{"title":"Boost efficiency with buffer and bottom stack optimization in Cu2BaSn(S,Se)4 solar cells by simulation","authors":"Kaviya Tracy Arockiya Dass, Aruna-Devi Rasu Chettiar, Evangeline Linda, Latha Marasamy","doi":"10.1016/j.jallcom.2024.177707","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177707","url":null,"abstract":"Cu<sub>2</sub>BaSn(S,Se)<sub>4</sub> is gaining tremendous attention as a potential absorber due to its non-toxicity, earth abundance, and low antisite defects opposing Cu<sub>2</sub>ZnSn(S,Se)<sub>4</sub>. However, the highest experimental efficiency of 6.17% is achieved with the device structure Al:ZnO/Mg:ZnO/Zn<sub>1-x</sub>Cd<sub>x</sub>S/Cu<sub>2</sub>BaSn(S,Se)<sub>4</sub>/Mo where the drawback is large open circuit voltage (V<sub>OC</sub>) loss stemming from the large cliff at the absorber/buffer interface and back contact recombination. Therefore, finding a suitable non-toxic buffer with modification of the bottom stack is crucial. In this regard, Cu<sub>2</sub>BaSn(S,Se)<sub>4</sub> solar cells based on diverse buffers are numerically simulated using SCAPS-1D with Ni as back contact and introducing back surface field (BSF) at the absorber/Ni interface. At first, a baseline model validating the experimental efficiency is designed. The application of Ni enhanced efficiency to 7.92% due to the formation of ohmic contact. Further, it is improved to 9.91% with anti-reflection coating. Afterward, a total of 780 solar cells were designed with six buffer and eight BSF combinations by optimizing the absorber, buffer, and interface properties where the highest efficiency of 28.11% with incredible fill factor (90%) and less V<sub>OC</sub> loss (0.24<!-- --> <!-- -->V) is accomplished for the AZO/ZMO/TiO<sub>2</sub>/Cu<sub>2</sub>BaSn(S,Se)<sub>4</sub>/CuI/Ni solar cell. Further, the importance of BSF is analyzed via energy band diagrams, Mott-Schottky and Nyquist plots. The outcomes disclosed that the BSF greatly influences the energy band alignment, built-in potential, depletion width, and recombination resistance of solar cells, underscoring its significance in improving performance. Overall, the present work proposes an efficient strategy to modify the device configuration of Cu<sub>2</sub>BaSn(S,Se)<sub>4</sub> solar cells to enhance their efficiency.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"23 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Utilizing solar energy for photodegradation of organic contaminants is an attractive strategy for environmental remediation. However, the synthesis of photocatalysts for efficient use of solar energy remains a challenge. Herein, we designed and synthesized a hierarchical and porous g-C3N4 (CN) via thermal polymerization of 5-amino-1H-tetrazole (ATZ) and melamine molecules. Experimental results demonstrate that the incorporation of electron-deficient ATZ into the CN structure drastically promotes the separation and transport of photoexcited charge carriers, and increases the specific surface area and pore size of the sample. Based on these unique features, the optimal CN-ATZ1 sample exhibited excellent photocatalytic activity with a rate constant of 0.091 min-1 for the degradation of rhodamine B (RhB) under visible light irradiation, which was about 10.71 times higher than that of bulk CN. Radical trapping experiments demonstrate that the superoxide radical (•O2−) is the major active species during the photodegradation process. This study provides a feasible strategy for the design and construction of g-C3N4 photocatalysts with high degradation activity.
{"title":"Molecular doping of graphitic carbon nitride for enhanced visible light-driven photodegradation of organic contaminants","authors":"Guowei Wang, Shuang Fu, Peng Hou, Yuedong Li, Chunxue Cui, Tonghui Yi, Hongguang Zhang","doi":"10.1016/j.jallcom.2024.177713","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177713","url":null,"abstract":"Utilizing solar energy for photodegradation of organic contaminants is an attractive strategy for environmental remediation. However, the synthesis of photocatalysts for efficient use of solar energy remains a challenge. Herein, we designed and synthesized a hierarchical and porous g-C<sub>3</sub>N<sub>4</sub> (CN) via thermal polymerization of 5-amino-1H-tetrazole (ATZ) and melamine molecules. Experimental results demonstrate that the incorporation of electron-deficient ATZ into the CN structure drastically promotes the separation and transport of photoexcited charge carriers, and increases the specific surface area and pore size of the sample. Based on these unique features, the optimal CN-ATZ1 sample exhibited excellent photocatalytic activity with a rate constant of 0.091<!-- --> <!-- -->min<sup>-1</sup> for the degradation of rhodamine B (RhB) under visible light irradiation, which was about 10.71 times higher than that of bulk CN. Radical trapping experiments demonstrate that the superoxide radical (•O<sub>2</sub><sup>−</sup>) is the major active species during the photodegradation process. This study provides a feasible strategy for the design and construction of g-C<sub>3</sub>N<sub>4</sub> photocatalysts with high degradation activity.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"129 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-22DOI: 10.1016/j.jallcom.2024.177708
Yue Xia, Sulgiye Park, Jing Zhang, Pengcheng Mu, Haonan Li, LongCheng Liu, Hiroshi Watabe, Rodney C Ewing, Dongyan Yang, Yuhong Li
Domains of the weberite structure has been found in both intrinsic and extrinsic disordered-pyrochlore oxides. Here we report a study of the local structure of the weberite structure-type Ln3TaO7 (Ln = Y, Sm, Gd) and their response to ion beam irradiation. All pristine compositions exhibit C222₁ structures at both local and long-range scales. Upon irradiation up to 1×1015 ions/cm2, Ln3TaO7 (Ln = Y, Sm, Gd) maintained an ordered weberite structure with a unit cell volume expansion of less than 2.5%. Nanoindentation measurements demonstrate that these oxides possess excellent mechanical stability under radiation exposure. The observed radiation resistance and mechanical robustness suggest that Ln₃TaO₇ oxides are promising candidate materials for applications in high-radiation fields.
{"title":"The local-structure and radiation resistance of Ln3TaO7 (Ln = Y, Sm, Gd)","authors":"Yue Xia, Sulgiye Park, Jing Zhang, Pengcheng Mu, Haonan Li, LongCheng Liu, Hiroshi Watabe, Rodney C Ewing, Dongyan Yang, Yuhong Li","doi":"10.1016/j.jallcom.2024.177708","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177708","url":null,"abstract":"Domains of the weberite structure has been found in both intrinsic and extrinsic disordered-pyrochlore oxides. Here we report a study of the local structure of the weberite structure-type Ln<sub>3</sub>TaO<sub>7</sub> (Ln = Y, Sm, Gd) and their response to ion beam irradiation. All pristine compositions exhibit C222₁ structures at both local and long-range scales. Upon irradiation up to 1×10<sup>15<!-- --> </sup>ions/cm<sup>2</sup>, Ln<sub>3</sub>TaO<sub>7</sub> (Ln = Y, Sm, Gd) maintained an ordered weberite structure with a unit cell volume expansion of less than 2.5%. Nanoindentation measurements demonstrate that these oxides possess excellent mechanical stability under radiation exposure. The observed radiation resistance and mechanical robustness suggest that Ln₃TaO₇ oxides are promising candidate materials for applications in high-radiation fields.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"12 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-22DOI: 10.1016/j.jallcom.2024.177710
Zhenzhen Guo, Haoran Zhang, Jiameng Zhang, Najah Alwadie, Lingyao Duan, Yunling Li, Zhenyu Hou, Van-Duong Dao, Muhammad Sultan Irshad
Molybdenum disulfide (MoS2) has emerged as a promising material for room-temperature gas sensing applications. However, its practical use is constrained by stability issues. To address this, the in-situ growth of MoS2 nanoflakes on MXenes (Ti3C2) nanobelts is reported for efficient ammonia (NH3) gas sensing applications under ambient conditions. The MoS2 nanoflakes are grown successfully on Ti3C2 nanobelts via a facile one-step hydrothermal method and analyzed by state-of-the-art investigations. The design of the gas sensor is to anchor MoS2/Ti3C2 onto a ceramic tube with a pair of gold electrodes. The results demonstrate that the sensor fabricated exhibits rapid, selective and stable response for NH3 at room temperature. Specifically, the sensor shows a significant gas response (~10%) to 100 ppm NH3, outperforming the pure MoS2 based sensor (~7%). More importantly, the sensor maintains performance at 1 ppm NH3, with a gas response of 2.5%, a response time of 10 seconds, and a recovery time of 7 seconds. These enhancements are attributed to the synergistic effects between MoS2 and Ti3C2, which not only improve stability but also enhance gas sensing capabilities. This study elucidates the potential of MoS2/Ti3C2 composites for achieving reliable and efficient NH3 sensing at room temperature, paving the way for advanced gas sensing technology.
{"title":"Tailoring MoS2 nanoflakes over MXenes nanobelts for efficient ammonia detection at room temperature","authors":"Zhenzhen Guo, Haoran Zhang, Jiameng Zhang, Najah Alwadie, Lingyao Duan, Yunling Li, Zhenyu Hou, Van-Duong Dao, Muhammad Sultan Irshad","doi":"10.1016/j.jallcom.2024.177710","DOIUrl":"https://doi.org/10.1016/j.jallcom.2024.177710","url":null,"abstract":"Molybdenum disulfide (MoS<sub>2</sub>) has emerged as a promising material for room-temperature gas sensing applications. However, its practical use is constrained by stability issues. To address this, the in-situ growth of MoS<sub>2</sub> nanoflakes on MXenes (Ti<sub>3</sub>C<sub>2</sub>) nanobelts is reported for efficient ammonia (NH<sub>3</sub>) gas sensing applications under ambient conditions. The MoS<sub>2</sub> nanoflakes are grown successfully on Ti<sub>3</sub>C<sub>2</sub> nanobelts via a facile one-step hydrothermal method and analyzed by state-of-the-art investigations. The design of the gas sensor is to anchor MoS<sub>2</sub>/Ti<sub>3</sub>C<sub>2</sub> onto a ceramic tube with a pair of gold electrodes. The results demonstrate that the sensor fabricated exhibits rapid, selective and stable response for NH<sub>3</sub> at room temperature. Specifically, the sensor shows a significant gas response (~10%) to 100 ppm NH<sub>3</sub>, outperforming the pure MoS<sub>2</sub> based sensor (~7%). More importantly, the sensor maintains performance at 1 ppm NH<sub>3</sub>, with a gas response of 2.5%, a response time of 10<!-- --> <!-- -->seconds, and a recovery time of 7<!-- --> <!-- -->seconds. These enhancements are attributed to the synergistic effects between MoS<sub>2</sub> and Ti<sub>3</sub>C<sub>2</sub>, which not only improve stability but also enhance gas sensing capabilities. This study elucidates the potential of MoS<sub>2</sub>/Ti<sub>3</sub>C<sub>2</sub> composites for achieving reliable and efficient NH<sub>3</sub> sensing at room temperature, paving the way for advanced gas sensing technology.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":"255 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142691043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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