Pub Date : 2024-11-22DOI: 10.1016/j.jmat.2024.100973
Yongjin Chen, Hong Wu, Guang Han, Bin Zhang, Xu Lu, Wenge Yang, Guoyu Wang, Xiaodong Han, Xiaoyuan Zhou
Pseudo-binary layered compound ⅣVI-V2VI3 families show great promise for application in thermoelectrics. Herein, through introducing iodine in GeSb2Te4, several synergistic effects come into being and contribute to outstanding thermoelectric performance. The ITe donor-like defects suppress the hole carrier concentration from 5.72 × 1020 cm–3 to 2.80 × 1020 cm–3. First-principles calculations reveal that iodine doping increases the band gap from 0.253 eV to 0.302 eV and contributes to valence band convergence. Seebeck coefficient value reaches up to 135.7 μV/K at 773 K, and the power factor values are entirely boosted in the whole temperature region, reaching a maximum value of 12.4 μW⸱cm–1⸱K–2 in GeSb2Te3.96I0.04. Moreover, iodine doping simultaneously reduces the lattice and electronic thermal conductivity, leading to the greatly reduced total thermal conductivity from 2.89 W⸱m–1⸱K–1 in pristine sample to 0.89 W⸱m–1⸱K–1 in GeSb2Te3.84I0.16 at 323 K. Finally, a maximum zT ∼ 1.12 at 773 K and an average zT ∼ 0.62 over 323–773 K are achieved in GeSb2Te3.88I0.12. This work puts forward an effective strategy to synergistically optimize phonon and carrier transport properties of pseudo-binary compounds through halogen doping, which may be effective in other similar material systems.
{"title":"Synergistic effects lead to high thermoelectric performance of iodine doped pseudo-binary layered GeSb2Te4","authors":"Yongjin Chen, Hong Wu, Guang Han, Bin Zhang, Xu Lu, Wenge Yang, Guoyu Wang, Xiaodong Han, Xiaoyuan Zhou","doi":"10.1016/j.jmat.2024.100973","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100973","url":null,"abstract":"Pseudo-binary layered compound ⅣVI-V<sub>2</sub>VI<sub>3</sub> families show great promise for application in thermoelectrics. Herein, through introducing iodine in GeSb<sub>2</sub>Te<sub>4</sub>, several synergistic effects come into being and contribute to outstanding thermoelectric performance. The I<sup>Te</sup> donor-like defects suppress the hole carrier concentration from 5.72 × 10<sup>20</sup> cm<sup>–3</sup> to 2.80 × 10<sup>20</sup> cm<sup>–3</sup>. First-principles calculations reveal that iodine doping increases the band gap from 0.253 eV to 0.302 eV and contributes to valence band convergence. Seebeck coefficient value reaches up to 135.7 μV/K at 773 K, and the power factor values are entirely boosted in the whole temperature region, reaching a maximum value of 12.4 μW⸱cm<sup>–1</sup>⸱K<sup>–2</sup> in GeSb<sub>2</sub>Te<sub>3.96</sub>I<sub>0.04</sub>. Moreover, iodine doping simultaneously reduces the lattice and electronic thermal conductivity, leading to the greatly reduced total thermal conductivity from 2.89 W⸱m<sup>–1</sup>⸱K<sup>–1</sup> in pristine sample to 0.89 W⸱m<sup>–1</sup>⸱K<sup>–1</sup> in GeSb<sub>2</sub>Te<sub>3.84</sub>I<sub>0.16</sub> at 323 K. Finally, a maximum <em>zT</em> ∼ 1.12 at 773 K and an average <em>zT</em> ∼ 0.62 over 323–773 K are achieved in GeSb<sub>2</sub>Te<sub>3.88</sub>I<sub>0.12</sub>. This work puts forward an effective strategy to synergistically optimize phonon and carrier transport properties of pseudo-binary compounds through halogen doping, which may be effective in other similar material systems.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"23 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684805","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 : 2024-11-22DOI: 10.1016/j.jmat.2024.100978
Yunhao Ma, Shan Wang, Yingjie Zhang, Bei Cheng, Liuyang Zhang
The development of heterojunction photocatalysts for hydrogen peroxide (H2O2) generation is both environmentally sustainable and cost-effective but presents considerable challenges. In this study, we synthesized hollow tubular indium oxide (In2O3) by calcining In-MIL-68 and subsequently composited it with polydopamine (PDA) via in-situ self-polymerization. This process resulted in the formation of an In2O3/PDA step-scheme (S-scheme) heterojunction. The optimized sample demonstrated H2O2 production rates approximately 2.1 and 4.5 times higher than the pure In2O3 and PDA, respectively. The enhanced photocatalytic performance of the In2O3/PDA composite is the result of several synergistic factors: increased light absorption due to the hollow structure, a larger specific surface area, and high separation efficiency of photo-generated electron-hole pairs facilitated by the S-scheme heterojunction. In-situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) confirmed the charge transfer pathway follows the S-scheme mechanism. This work not only highlights a practical method for constructing inorganic/organic S-scheme heterojunction photocatalysts but also provides a detailed analysis of their underlying mechanisms, paving the way for more efficient and sustainable photocatalytic systems.
开发用于生成过氧化氢（H2O2）的异质结光催化剂既具有环境可持续性，又具有成本效益，但同时也面临着相当大的挑战。在本研究中，我们通过煅烧 In-MIL-68 合成了空心管状氧化铟（In2O3），随后通过原位自聚合将其与多巴胺（PDA）复合。这一过程形成了 In2O3/PDA 阶梯式（S-scheme）异质结。优化样品的 H2O2 生成率分别是纯 In2O3 和 PDA 的约 2.1 倍和 4.5 倍。In2O3/PDA 复合材料光催化性能的增强是几个协同因素共同作用的结果：中空结构增加了光吸收，比表面积增大，S-scheme 异质结促进了光生电子-空穴对的高分离效率。原位辐照 X 射线光电子能谱（ISI-XPS）证实电荷转移途径遵循 S 型机制。这项工作不仅强调了构建无机/有机 S 型异质结光催化剂的实用方法，还详细分析了其基本机制，为建立更高效、更可持续的光催化系统铺平了道路。
{"title":"Convenient synthesis of hollow tubular In2O3/PDA S-scheme inorganic/organic heterojunction photocatalyst for H2O2 production and its mechanism","authors":"Yunhao Ma, Shan Wang, Yingjie Zhang, Bei Cheng, Liuyang Zhang","doi":"10.1016/j.jmat.2024.100978","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100978","url":null,"abstract":"The development of heterojunction photocatalysts for hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) generation is both environmentally sustainable and cost-effective but presents considerable challenges. In this study, we synthesized hollow tubular indium oxide (In<sub>2</sub>O<sub>3</sub>) by calcining In-MIL-68 and subsequently composited it with polydopamine (PDA) <em>via in-situ</em> self-polymerization. This process resulted in the formation of an In<sub>2</sub>O<sub>3</sub>/PDA step-scheme (S-scheme) heterojunction. The optimized sample demonstrated H<sub>2</sub>O<sub>2</sub> production rates approximately 2.1 and 4.5 times higher than the pure In<sub>2</sub>O<sub>3</sub> and PDA, respectively. The enhanced photocatalytic performance of the In<sub>2</sub>O<sub>3</sub>/PDA composite is the result of several synergistic factors: increased light absorption due to the hollow structure, a larger specific surface area, and high separation efficiency of photo-generated electron-hole pairs facilitated by the S-scheme heterojunction. <em>In-situ</em> irradiated X-ray photoelectron spectroscopy (ISI-XPS) confirmed the charge transfer pathway follows the S-scheme mechanism. This work not only highlights a practical method for constructing inorganic/organic S-scheme heterojunction photocatalysts but also provides a detailed analysis of their underlying mechanisms, paving the way for more efficient and sustainable photocatalytic systems.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"17 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684746","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 : 2024-11-21DOI: 10.1016/j.jmat.2024.100976
Qingxi Zhao, Hongwei Chu, Zhongben Pan, Han Pan, Shengzhi Zhao, Dechun Li
Fe2O3 nanomaterials, as one of the transition metal oxides (TMOs) materials, have garnered attention in ultrafast photonics due to their robust third-order nonlinearity, rapid carrier recovery time, high stability, broad absorption bandwidth and straightforward preparation methods. In order to further enhance the performance of Fe2O3 nanomaterials, oxygen vacancy defects were introduced in the process of preparing the Fe2O3 nanomaterials in this paper. By characterizing the nonlinear optical properties of the prepared Fe2O3 nanomaterials with different surface oxygen vacancy concentrations, we found that Fe2O3 nanomaterials with larger oxygen vacancy content have a deeper modulation depth and the larger third-order nonlinear coefficient. It also indicated that the incorporation of oxygen vacancy defects can significantly enhance the nonlinear optical properties of Fe2O3 nanomaterials. Furthermore, the ultrafast carrier dynamics of Fe2O3 materials with varying concentrations of oxygen vacancies were investigated using femtosecond-resolved transient absorption (TA) spectroscopy, elucidating the microscopic mechanism. Finally, we inserted Fe2O3-based saturable absorbers into Yb- and Er-doped fiber lasers. Noise-like mode-locking operation and multi-pulse mode-locking operation are realized at 1 μm in the Yb-doped fiber laser. Besides, the conventional soliton mode-locking operations with different central wavelengths are realized within 1.5 μm band in an Er-doped fiber laser.
{"title":"Surface oxygen vacancies in amorphous Fe2O3 tailored nonlinear optical properties for ultrafast photonics","authors":"Qingxi Zhao, Hongwei Chu, Zhongben Pan, Han Pan, Shengzhi Zhao, Dechun Li","doi":"10.1016/j.jmat.2024.100976","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100976","url":null,"abstract":"Fe<sub>2</sub>O<sub>3</sub> nanomaterials, as one of the transition metal oxides (TMOs) materials, have garnered attention in ultrafast photonics due to their robust third-order nonlinearity, rapid carrier recovery time, high stability, broad absorption bandwidth and straightforward preparation methods. In order to further enhance the performance of Fe<sub>2</sub>O<sub>3</sub> nanomaterials, oxygen vacancy defects were introduced in the process of preparing the Fe<sub>2</sub>O<sub>3</sub> nanomaterials in this paper. By characterizing the nonlinear optical properties of the prepared Fe<sub>2</sub>O<sub>3</sub> nanomaterials with different surface oxygen vacancy concentrations, we found that Fe<sub>2</sub>O<sub>3</sub> nanomaterials with larger oxygen vacancy content have a deeper modulation depth and the larger third-order nonlinear coefficient. It also indicated that the incorporation of oxygen vacancy defects can significantly enhance the nonlinear optical properties of Fe<sub>2</sub>O<sub>3</sub> nanomaterials. Furthermore, the ultrafast carrier dynamics of Fe<sub>2</sub>O<sub>3</sub> materials with varying concentrations of oxygen vacancies were investigated using femtosecond-resolved transient absorption (TA) spectroscopy, elucidating the microscopic mechanism. Finally, we inserted Fe<sub>2</sub>O<sub>3</sub>-based saturable absorbers into Yb- and Er-doped fiber lasers. Noise-like mode-locking operation and multi-pulse mode-locking operation are realized at 1 μm in the Yb-doped fiber laser. Besides, the conventional soliton mode-locking operations with different central wavelengths are realized within 1.5 μm band in an Er-doped fiber laser.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"1 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678336","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 : 2024-11-21DOI: 10.1016/j.jmat.2024.100977
Guoqing Ma, Di Zhou, Yunlong Xie, Shuhan Zheng, Meifeng Liu, Leili Tan, Zhen Liu, Fei Liu, Yao Li, Zhen Ma, Yongjun Zhang, Lin Lin, Min Zeng, Xiuzhang Wang, Saiyu Wang, Hong Li, Shuai Dong, Jun-Ming Liu
Fe2TeO6 has long been considered as a promising high-temperature magnetoelectric (ME) material, while the magnetoelectricity and magnetic ground state of Fe2TeO6 have not been well characterized or understood yet. In the present work, we report the systematical study of magnetism, ferroelectricity, ME effect, first principles calculation, and Monte Carlo simulation of Fe2TeO6 single crystals. Fe2TeO6 exhibits linear ME effect below TN ∼ 208 K, and only diagonal ME coefficients appears to be non-zero, which agrees with the magnetic point group 4/m'm'm'. The calculated magnetic ground state agrees with previous neutron diffraction, and the strong intra(inter)-bilayer interactions coincide with the high TN of Fe2TeO6. This work will contribute to the understanding of A2BO6 ME family and the exploration of high temperature ME materials.
一直以来，Fe2TeO6 被认为是一种很有前途的高温磁电（ME）材料，但人们对 Fe2TeO6 的磁电性和磁基态还没有很好的表征和理解。在本研究中，我们报告了对 Fe2TeO6 单晶的磁性、铁电性、ME 效应、第一性原理计算和蒙特卡罗模拟的系统研究。Fe2TeO6 在 TN ∼ 208 K 以下表现出线性 ME 效应，且只有对角线 ME 系数不为零，这与磁点群 4/m'm'm' 相吻合。计算出的磁基态与之前的中子衍射结果一致，而强的层内（层间）相互作用与 Fe2TeO6 的高 TN 相吻合。这项工作将有助于理解 A2BO6 ME 家族和探索高温 ME 材料。
{"title":"High temperature magnetoelectric effect in Fe2TeO6","authors":"Guoqing Ma, Di Zhou, Yunlong Xie, Shuhan Zheng, Meifeng Liu, Leili Tan, Zhen Liu, Fei Liu, Yao Li, Zhen Ma, Yongjun Zhang, Lin Lin, Min Zeng, Xiuzhang Wang, Saiyu Wang, Hong Li, Shuai Dong, Jun-Ming Liu","doi":"10.1016/j.jmat.2024.100977","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100977","url":null,"abstract":"Fe<sub>2</sub>TeO<sub>6</sub> has long been considered as a promising high-temperature magnetoelectric (ME) material, while the magnetoelectricity and magnetic ground state of Fe<sub>2</sub>TeO<sub>6</sub> have not been well characterized or understood yet. In the present work, we report the systematical study of magnetism, ferroelectricity, ME effect, first principles calculation, and Monte Carlo simulation of Fe<sub>2</sub>TeO<sub>6</sub> single crystals. Fe<sub>2</sub>TeO<sub>6</sub> exhibits linear ME effect below <em>T</em><sub>N</sub> ∼ 208 K, and only diagonal ME coefficients appears to be non-zero, which agrees with the magnetic point group <em>4/m'm'm'</em>. The calculated magnetic ground state agrees with previous neutron diffraction, and the strong intra(inter)-bilayer interactions coincide with the high <em>T</em><sub>N</sub> of Fe<sub>2</sub>TeO<sub>6</sub>. This work will contribute to the understanding of A<sub>2</sub>BO<sub>6</sub> ME family and the exploration of high temperature ME materials.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"191 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678337","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}
Recently, the step-scheme (S-scheme) heterojunction has gained significant attention due to its effective electron-hole separation and strong redox capabilities. However, reports on covalent organic framework (COF)-based S-scheme heterojunctions for photocatalytic RhB degradation remain limited. In this study, an S-scheme ZnIn2S4@COF-5 heterojunction photocatalyst was successfully synthesized by growing COF-5 on the surface of ZnIn2S4 nanosheets, achieving efficient RhB degradation. Using 30 mg of COF-5@ ZnIn2S4, we degraded 50 mL of an 80 ppm RhB solution, achieving a 97% removal rate within 90 minutes. The photocatalytic performance of the COF-5@ ZnIn2S4 S-scheme heterojunction was approximately 1.7 times higher than that of ZnIn2S4 and 1.6 times higher than COF-5 alone. Compared to the other reported COF-based S-scheme heterojunctions and commercial photocatalysts, this ZnIn2S4@COF-5 photocatalyst exhibited superior photocatalytic performance. The S-scheme charge transfer mechanism of the ZnIn2S4@COF-5 heterojunction was elucidated through in situ irradiated XPS. Experimental results demonstrate that this rational design not only facilitates the effective separation of photogenerated electrons and holes, but also provides a large surface area and abundant active sites for efficient RhB degradation.
{"title":"In situ irradiated XPS investigation on S-Scheme ZnIn2S4@COF-5 photocatalyst for enhanced photocatalytic degradation of RhB","authors":"Jian Sun, Haowei Liu, Shan Wang, Yingjie Zhang, Chuanbiao Bie, Liuyang Zhang","doi":"10.1016/j.jmat.2024.100975","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100975","url":null,"abstract":"Recently, the step-scheme (S-scheme) heterojunction has gained significant attention due to its effective electron-hole separation and strong redox capabilities. However, reports on covalent organic framework (COF)-based S-scheme heterojunctions for photocatalytic RhB degradation remain limited. In this study, an S-scheme ZnIn<sub>2</sub>S<sub>4</sub>@COF-5 heterojunction photocatalyst was successfully synthesized by growing COF-5 on the surface of ZnIn<sub>2</sub>S<sub>4</sub> nanosheets, achieving efficient RhB degradation. Using 30 mg of COF-5@ ZnIn<sub>2</sub>S<sub>4</sub>, we degraded 50 mL of an 80 ppm RhB solution, achieving a 97% removal rate within 90 minutes. The photocatalytic performance of the COF-5@ ZnIn<sub>2</sub>S<sub>4</sub> S-scheme heterojunction was approximately 1.7 times higher than that of ZnIn<sub>2</sub>S<sub>4</sub> and 1.6 times higher than COF-5 alone. Compared to the other reported COF-based S-scheme heterojunctions and commercial photocatalysts, this ZnIn<sub>2</sub>S<sub>4</sub>@COF-5 photocatalyst exhibited superior photocatalytic performance. The S-scheme charge transfer mechanism of the ZnIn<sub>2</sub>S<sub>4</sub>@COF-5 heterojunction was elucidated through in situ irradiated XPS. Experimental results demonstrate that this rational design not only facilitates the effective separation of photogenerated electrons and holes, but also provides a large surface area and abundant active sites for efficient RhB degradation.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"130 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678338","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 : 2024-11-20DOI: 10.1016/j.jmat.2024.100972
Qing-Qiao Fu, Hui Gu, Juan-Juan Xing, Qiang Zheng
High dielectric constant can be reached in a reductive-sintered Sr1–xBaxTiO3 barrier-layer capacitor with core‒rim structures as dominant microstructural features. By SEM and aberration-corrected TEM observations, an interfacial zone between the core and rim, named as white-rim (w-rim), was found always enriched with Ba, while the core was free of Ba solution. The reductive liquid-phase sintering resulted in three times the concentrations of oxygen vacancies (VO) into cores and rims compared to their A-site vacancies (VA), while enabling the highest concentration of VO (∼17%) without VA in w-rim. The strained core/w-rim interfaces, with obvious interfacial polarizations, which can effectively raise the dielectric constant, were expected to be created from a temporary equilibrium between the cores and the liquid-phase. The synergetic evolution of core‒rim structures, Sr‒O vacancies, multiple internal polarized structures can be utilized to better control and optimize dielectric behaviors and other functionalities for perovskite capacitors and other multi-functional ceramics.
还原烧结的 Sr1-xBaxTiO3 屏障层电容器可以达到很高的介电常数，其主要的微观结构特征是芯-边结构。通过扫描电子显微镜和像差校正 TEM 观察，发现在核心和边缘之间的界面区总是富含钡，而核心则不含钡溶液，该界面区被命名为白边（w-rim）。还原液相烧结使炉芯和炉缘中的氧空位（VO）浓度是其 A 位空位（VA）浓度的三倍，同时使 w-rim 中的 VO（∼17%）浓度达到最高，而不含 VA。应变型内核/外圈界面具有明显的界面极化，可有效提高介电常数，预计是由内核和液相之间的临时平衡产生的。可以利用核心-边缘结构、Sr-O 空位、多重内部极化结构的协同演化，更好地控制和优化过氧化物电容器和其他多功能陶瓷的介电行为和其他功能。
{"title":"Synergetic engineering of Sr‒O vacancies and core‒rim interfacial structures in dielectric Sr1–xBaxTiO3 ceramics","authors":"Qing-Qiao Fu, Hui Gu, Juan-Juan Xing, Qiang Zheng","doi":"10.1016/j.jmat.2024.100972","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100972","url":null,"abstract":"High dielectric constant can be reached in a reductive-sintered Sr<sub>1–<em>x</em></sub>Ba<sub><em>x</em></sub>TiO<sub>3</sub> barrier-layer capacitor with core‒rim structures as dominant microstructural features. By SEM and aberration-corrected TEM observations, an interfacial zone between the core and rim, named as white-rim (w-rim), was found always enriched with Ba, while the core was free of Ba solution. The reductive liquid-phase sintering resulted in three times the concentrations of oxygen vacancies (V<sub>O</sub>) into cores and rims compared to their A-site vacancies (V<sub>A</sub>), while enabling the highest concentration of V<sub>O</sub> (∼17%) without V<sub>A</sub> in w-rim. The strained core/w-rim interfaces, with obvious interfacial polarizations, which can effectively raise the dielectric constant, were expected to be created from a temporary equilibrium between the cores and the liquid-phase. The synergetic evolution of core‒rim structures, Sr‒O vacancies, multiple internal polarized structures can be utilized to better control and optimize dielectric behaviors and other functionalities for perovskite capacitors and other multi-functional ceramics.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"18 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673401","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}
Pure ZnO exhibits low photocatalytic H2O2 production activity due to the rapid charge recombination. To realize the spatial separation of photogenerated electrons and holes, constructing an electron transfer channel on the ZnO surface is an effective approach. This study successfully modified the surface of ZnO using F– (ZnO/F) by introducing NH4F in an aqueous phase photocatalytic system. The F– is adsorbed on the ZnO surface by Coulombic force and significantly improves the photocatalytic H2O2 production performance of ZnO, with the highest efficiency of 4137.2 μmol·g–1·L–1·h–-1. The photocatalytic performance enhancement mechanism of ZnO/F is explained in terms of electron transfer dynamics by femtosecond transient absorption spectroscopy (fs-TAS) measurements. F– surface modification constructs a new ultrafast electron transport pathway from the ZnO CB to F–, and the optimal ZnO/F exhibits the fastest interfacial electron transfer lifetime of 5.8 ps. The F– surface modification effectively facilitates the charge separation, thereby increasing the number of electrons available for photocatalytic H2O2 reaction. This study has revealed the roles of F– surface modification in the photocatalytic H2O2 production by ZnO and provides guidance for ionic modification to improve photocatalytic performance.
{"title":"F− surface modified ZnO for enhanced photocatalytic H2O2 production and its fs-TAS investigation","authors":"Xin Zhou, Chenbin Ai, Xiaojing Wang, Zhen Wu, Jianjun Zhang","doi":"10.1016/j.jmat.2024.100974","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100974","url":null,"abstract":"Pure ZnO exhibits low photocatalytic H<sub>2</sub>O<sub>2</sub> production activity due to the rapid charge recombination. To realize the spatial separation of photogenerated electrons and holes, constructing an electron transfer channel on the ZnO surface is an effective approach. This study successfully modified the surface of ZnO using F<sup>–</sup> (ZnO/F) by introducing NH<sub>4</sub>F in an aqueous phase photocatalytic system. The F<sup>–</sup> is adsorbed on the ZnO surface by Coulombic force and significantly improves the photocatalytic H<sub>2</sub>O<sub>2</sub> production performance of ZnO, with the highest efficiency of 4137.2 μmol·g<sup>–1</sup>·L<sup>–1</sup>·h<sup>–-1</sup>. The photocatalytic performance enhancement mechanism of ZnO/F is explained in terms of electron transfer dynamics by femtosecond transient absorption spectroscopy (fs-TAS) measurements. F<sup>–</sup> surface modification constructs a new ultrafast electron transport pathway from the ZnO CB to F<sup>–</sup>, and the optimal ZnO/F exhibits the fastest interfacial electron transfer lifetime of 5.8 ps. The F<sup>–</sup> surface modification effectively facilitates the charge separation, thereby increasing the number of electrons available for photocatalytic H<sub>2</sub>O<sub>2</sub> reaction. This study has revealed the roles of F<sup>–</sup> surface modification in the photocatalytic H<sub>2</sub>O<sub>2</sub> production by ZnO and provides guidance for ionic modification to improve photocatalytic performance.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"112 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673400","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 : 2024-11-19DOI: 10.1016/j.jmat.2024.100971
Yichen Li, Yao Yao, Lei Zhou, Jing Wang, Lei Zhao
Relaxor ferroelectrics are the primary candidates for high-performance energy storage dielectric capacitors. Here, stress engineering, which was realized by optimizing the lattice mismatch between (Na0.5Bi0.5)TiO3 film and SrRuO3/(La0.5Sr0.5)CoO3 bottom electrodes, was used to enhance the energy storage performance of (Na0.5Bi0.5)TiO3 relaxor ferroelectric film. As a result, in-plane compressive stress caused by the lattice mismatch between (Na0.5Bi0.5)TiO3 film and (La0.5Sr0.5)CoO3 bottom electrode leads to a large Wrec of 45.7 J/cm3 with η of 79.4% at 2000 kV/cm in (Na0.5Bi0.5)TiO3 film, which is 54.4% higher than that of (Na0.5Bi0.5)TiO3 film with in-plane tensile stress. In addition, the Wrec of (Na0.5Bi0.5)TiO3 film with in-plane compressive stress shows good thermal stability and frequency stability with variations of 5.8% at 30–120 °C and 6.9% at 0.2–20.0 kHz. This work may provide some new perspectives for the design of dielectric capacitors with high energy storage performance.
{"title":"High energy storage performance of (Na0.5Bi0.5)TiO3 thin film induced by stress engineering","authors":"Yichen Li, Yao Yao, Lei Zhou, Jing Wang, Lei Zhao","doi":"10.1016/j.jmat.2024.100971","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100971","url":null,"abstract":"Relaxor ferroelectrics are the primary candidates for high-performance energy storage dielectric capacitors. Here, stress engineering, which was realized by optimizing the lattice mismatch between (Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> film and SrRuO<sub>3</sub>/(La<sub>0.5</sub>Sr<sub>0.5</sub>)CoO<sub>3</sub> bottom electrodes, was used to enhance the energy storage performance of (Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> relaxor ferroelectric film. As a result, in-plane compressive stress caused by the lattice mismatch between (Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> film and (La<sub>0.5</sub>Sr<sub>0.5</sub>)CoO<sub>3</sub> bottom electrode leads to a large <em>W</em><sub>rec</sub> of 45.7 J/cm<sup>3</sup> with <em>η</em> of 79.4% at 2000 kV/cm in (Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> film, which is 54.4% higher than that of (Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> film with in-plane tensile stress. In addition, the <em>W</em><sub>rec</sub> of (Na<sub>0.5</sub>Bi<sub>0.5</sub>)TiO<sub>3</sub> film with in-plane compressive stress shows good thermal stability and frequency stability with variations of 5.8% at 30–120 °C and 6.9% at 0.2–20.0 kHz. This work may provide some new perspectives for the design of dielectric capacitors with high energy storage performance.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"250 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670866","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 : 2024-11-17DOI: 10.1016/j.jmat.2024.100969
Xiao Xu, Yao Xiao, Xuelian Xu, Sónia A.C. Carabineiro, Junjiang Zhu
Graphitic carbon nitride (C3N4) is a promising photocatalyst due to its suitable band gap and polymer properties, but its efficiency is limited by the poor separation of photoinduced electron/hole (e–/h+) pairs. To address this issue, we propose creating N vacancies within the layers and bridging K single-atoms between the C3N4 layers through the self-assembly of potassium citrate and melamine–urea monomers. The introduction of N vacancies disrupts the symmetry of C3N4, promoting electron transfer along the delocalized π-conjugated network, while the presence of K atoms provides channels for electron transfer between the layers by forming N–K–N bridges, thereby leading to significant enhancement in the separation and transfer of e–/h+ pairs across spatial dimension. As expected, the co-modified C3N4, with N vacancies and K single-atoms (designated as CN-K-VN), exhibits excellent photocatalytic performance, with reaction rate constant of 9.69×10–2 min–1 (7.39×10–2 min–1 in real water environment) for tetracycline, achieving 80% degradation of tetracycline within 20 minutes. The reaction mechanism, as well as the toxicity of the degradation intermediates, is deeply discussed. This study provides a strategy to enhance the spatial separation of electrons for photocatalyst, highlighting its significance role in photocatalysis.
氮化石墨碳（C3N4）具有合适的带隙和聚合物特性，是一种前景广阔的光催化剂，但其效率却受到光诱导电子/空穴（e-/h+）对分离不良的限制。为解决这一问题，我们建议通过柠檬酸钾和三聚氰胺脲单体的自组装，在层内产生 N 空位，并在 C3N4 层之间桥接 K 单原子。N 空位的引入破坏了 C3N4 的对称性，促进了电子沿分散的 π 共轭网络转移，而 K 原子的存在则通过形成 N-K-N 桥为层间的电子转移提供了通道，从而显著增强了 e-/h+ 对在空间维度上的分离和转移。正如预期的那样，含有 N 空位和 K 单原子的共修饰 C3N4（命名为 CN-K-VN）表现出优异的光催化性能，对四环素的反应速率常数为 9.69×10-2 min-1（在实际水环境中为 7.39×10-2 min-1），在 20 分钟内实现了对四环素 80% 的降解。该研究对反应机理以及降解中间产物的毒性进行了深入探讨。这项研究提供了一种增强光催化剂电子空间分离的策略，凸显了光催化剂在光催化中的重要作用。
{"title":"Dual-site engineering of N vacancies and K single-atoms in C3N4: Enabling spatial charge transfer channels for photocatalysis","authors":"Xiao Xu, Yao Xiao, Xuelian Xu, Sónia A.C. Carabineiro, Junjiang Zhu","doi":"10.1016/j.jmat.2024.100969","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100969","url":null,"abstract":"Graphitic carbon nitride (C<sub>3</sub>N<sub>4</sub>) is a promising photocatalyst due to its suitable band gap and polymer properties, but its efficiency is limited by the poor separation of photoinduced electron/hole (e<sup>–</sup>/h<sup>+</sup>) pairs. To address this issue, we propose creating N vacancies within the layers and bridging K single-atoms between the C<sub>3</sub>N<sub>4</sub> layers through the self-assembly of potassium citrate and melamine–urea monomers. The introduction of N vacancies disrupts the symmetry of C<sub>3</sub>N<sub>4</sub>, promoting electron transfer along the delocalized π-conjugated network, while the presence of K atoms provides channels for electron transfer between the layers by forming N<em>–</em>K<em>–</em>N bridges, thereby leading to significant enhancement in the separation and transfer of e<sup>–</sup>/h<sup>+</sup> pairs across spatial dimension. As expected, the co-modified C<sub>3</sub>N<sub>4</sub>, with N vacancies and K single-atoms (designated as CN-K-V<sub>N</sub>), exhibits excellent photocatalytic performance, with reaction rate constant of 9.69×10<sup>–2</sup> min<sup>–1</sup> (7.39×10<sup>–2</sup> min<sup>–1</sup> in real water environment) for tetracycline, achieving 80% degradation of tetracycline within 20 minutes. The reaction mechanism, as well as the toxicity of the degradation intermediates, is deeply discussed. This study provides a strategy to enhance the spatial separation of electrons for photocatalyst, highlighting its significance role in photocatalysis.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"76 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665426","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 : 2024-11-16DOI: 10.1016/j.jmat.2024.100967
Peng Wei, Hao Bai, Yang Liu, Lei Zhuang, Hulei Yu, Yanhui Chu
Exploring superior calcium-magnesium-aluminosilicate (CMAS) corrosion resistance is crucial for high-entropy rare-earth monosilicates (HEREMs) as the next-generation environmental barrier coating (EBC) materials. However, related studies are rarely reported. This work presents the exploration of HEREMs with remarkable CMAS corrosion resistance by engineering their compositions. The equimolar 3-to-9 cation high-entropy rare-earth monosilicate (3-9HEREM) specimens were initially prepared using a pressure-less sintering technique; subsequently, their resistance to CMAS corrosion was evaluated at temperatures up to 1,600 °C. The results demonstrate that the 5HEREM specimens possess the best CMAS corrosion resistance among all the as-fabricated specimens, surpassing other reported EBC materials. Such remarkable CMAS corrosion resistance results from the generation of a dense apatite protective layer originating from its low dissolution rate at elevated temperatures.
{"title":"Composition engineering of high-entropy rare-earth monosilicates enables remarkable CMAS corrosion resistance","authors":"Peng Wei, Hao Bai, Yang Liu, Lei Zhuang, Hulei Yu, Yanhui Chu","doi":"10.1016/j.jmat.2024.100967","DOIUrl":"https://doi.org/10.1016/j.jmat.2024.100967","url":null,"abstract":"Exploring superior calcium-magnesium-aluminosilicate (CMAS) corrosion resistance is crucial for high-entropy rare-earth monosilicates (HEREMs) as the next-generation environmental barrier coating (EBC) materials. However, related studies are rarely reported. This work presents the exploration of HEREMs with remarkable CMAS corrosion resistance by engineering their compositions. The equimolar 3-to-9 cation high-entropy rare-earth monosilicate (3-9HEREM) specimens were initially prepared using a pressure-less sintering technique; subsequently, their resistance to CMAS corrosion was evaluated at temperatures up to 1,600 °C. The results demonstrate that the 5HEREM specimens possess the best CMAS corrosion resistance among all the as-fabricated specimens, surpassing other reported EBC materials. Such remarkable CMAS corrosion resistance results from the generation of a dense apatite protective layer originating from its low dissolution rate at elevated temperatures.","PeriodicalId":16173,"journal":{"name":"Journal of Materiomics","volume":"38 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642743","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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