Haohui Li, Lili Yu, Ze Li, Sicheng Li, Ye Liu, Guiwen Qu, Kang Chen, Luqiao Huang, Zongan Li, Jianan Ren, Xiuwen Wu, Jinjian Huang
Hydrogel microspheres are important in regenerative medicine and tissue engineering, acting as cargos of cells, drugs, growth factors, bio-inks for 3D printing, and medical devices. The antimicrobial and anti-inflammatory characteristics of hydrogel microspheres are good for treating injured tissues. However, the biological properties of hydrogel microspheres should be modified for optimal treatment of various body parts with different physiological and biochemical environments. In addition, specific preparation methods are required to produce customized hydrogel microspheres with different shapes and sizes for various clinical applications. Herein, the advances in hydrogel microspheres for biomedical applications are reviewed. Synthesis methods for hydrogel precursor solutions, manufacturing methods, and strategies for enhancing the biological functions of these hydrogel microspheres are described. The involvement of bioactive hydrogel microspheres in tissue repair is also discussed. This review anticipates fostering more insights into the design, production, and application of hydrogel microspheres in biomedicine.
{"title":"A Narrative Review of Bioactive Hydrogel Microspheres: Ingredients, Modifications, Fabrications, Biological Functions, and Applications","authors":"Haohui Li, Lili Yu, Ze Li, Sicheng Li, Ye Liu, Guiwen Qu, Kang Chen, Luqiao Huang, Zongan Li, Jianan Ren, Xiuwen Wu, Jinjian Huang","doi":"10.1002/smll.202500426","DOIUrl":"https://doi.org/10.1002/smll.202500426","url":null,"abstract":"Hydrogel microspheres are important in regenerative medicine and tissue engineering, acting as cargos of cells, drugs, growth factors, bio-inks for 3D printing, and medical devices. The antimicrobial and anti-inflammatory characteristics of hydrogel microspheres are good for treating injured tissues. However, the biological properties of hydrogel microspheres should be modified for optimal treatment of various body parts with different physiological and biochemical environments. In addition, specific preparation methods are required to produce customized hydrogel microspheres with different shapes and sizes for various clinical applications. Herein, the advances in hydrogel microspheres for biomedical applications are reviewed. Synthesis methods for hydrogel precursor solutions, manufacturing methods, and strategies for enhancing the biological functions of these hydrogel microspheres are described. The involvement of bioactive hydrogel microspheres in tissue repair is also discussed. This review anticipates fostering more insights into the design, production, and application of hydrogel microspheres in biomedicine.","PeriodicalId":228,"journal":{"name":"Small","volume":"31 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654174","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}
Chenghui Qian, Si Chen, Liman Chen, Chenyang Zhang, Lingyi Yang, Qiaowei Li, Binbin Kang, Xiaohong Chen, Peter Mei, Hongzhou Gu, Yan Liu, Yuehua Liu
Titanium (Ti) is extensively used in the medical field because of its excellent biomechanical properties; however, how to precisely fabricate Ti surfaces at a nanoscale remains challenging. In this study, a DNA nanocoating system to functionalize Ti surfaces via a series of sequential reactions involving hydroxylation, silanization, and click chemistry is developed. Tetrahedral DNA nanostructures (TDNs) of two different sizes (≈7 and 30 nm) are assembled and characterized for subsequent surface attachment. In vitro and in vivo assays demonstrated significantly enhanced cell adhesion, spreading, proliferation, osteogenesis, and osseointegration on Ti surfaces modified with 30-nm TDNs, compared to slightly improved effects with 7-nm TDNs. Mechanistic studies showed that the focal adhesion pathway contributed to the enhanced bioaffinity of the 30-nm TDNs, as evidenced by the upregulated expression of vinculin and activation of the Akt signaling pathway. Moreover, under inflammatory or hypoxic conditions, Ti surfaces modified with 30-nm TDNs maintained excellent cellular performance comparable to that under normal conditions, suggesting a broader adaptability for DNA nanoparticles. Thus, better performance is achieved following modification with 30-nm TDNs. In summary, the proposed DNA-guided nanocoating system provides a novel and efficient strategy for the surface nanofabrication of Ti.
{"title":"Tetrahedral DNA Nanostructure-Modified Nanocoating for Improved Bioaffinity and Osseointegration of Titanium","authors":"Chenghui Qian, Si Chen, Liman Chen, Chenyang Zhang, Lingyi Yang, Qiaowei Li, Binbin Kang, Xiaohong Chen, Peter Mei, Hongzhou Gu, Yan Liu, Yuehua Liu","doi":"10.1002/smll.202412747","DOIUrl":"https://doi.org/10.1002/smll.202412747","url":null,"abstract":"Titanium (Ti) is extensively used in the medical field because of its excellent biomechanical properties; however, how to precisely fabricate Ti surfaces at a nanoscale remains challenging. In this study, a DNA nanocoating system to functionalize Ti surfaces via a series of sequential reactions involving hydroxylation, silanization, and click chemistry is developed. Tetrahedral DNA nanostructures (TDNs) of two different sizes (≈7 and 30 nm) are assembled and characterized for subsequent surface attachment. In vitro and in vivo assays demonstrated significantly enhanced cell adhesion, spreading, proliferation, osteogenesis, and osseointegration on Ti surfaces modified with 30-nm TDNs, compared to slightly improved effects with 7-nm TDNs. Mechanistic studies showed that the focal adhesion pathway contributed to the enhanced bioaffinity of the 30-nm TDNs, as evidenced by the upregulated expression of vinculin and activation of the Akt signaling pathway. Moreover, under inflammatory or hypoxic conditions, Ti surfaces modified with 30-nm TDNs maintained excellent cellular performance comparable to that under normal conditions, suggesting a broader adaptability for DNA nanoparticles. Thus, better performance is achieved following modification with 30-nm TDNs. In summary, the proposed DNA-guided nanocoating system provides a novel and efficient strategy for the surface nanofabrication of Ti.","PeriodicalId":228,"journal":{"name":"Small","volume":"25 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654209","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}
Lei Zhang, Xu-Yang Wang, Li Yang, Haozhi Wang, Qian-You Wang
Developing an effective tailoring approach to overcome the intrinsic trade-off between detonation power and safety in energetic materials is crucial for micro-electromechanical detonation systems but remains challenging. Herein, the anchoring of the high-energy-density yet highly sensitive primary explosive copper azide (CA) onto an N-doped reduced graphene oxide (NrGO) shell (denoted as CA@NrGO) is reported via electronic interactions. This approach simultaneously achieves a three-fold enhancement in mechanical safety, a ≈36-fold improvement in electrostatic safety compared to pure CA, and high detonation capacity. Theoretical calculations reveal that the electronic interaction between NrGO and CA not only facilitate energy dissipation from mechanical forces acting on CA—via intralayer compression and slip, thereby enhancing mechanical safety—but also promote interfacial electron transfer from CA to NrGO, preventing charge accumulation in CA and improving electrostatic safety. Furthermore, the excellent detonation power of CA@NrGO is demonstrated in a micro-detonation device, where 6 mg of CA@NrGO reliably initiated 20 mg of the secondary explosive CL-20. This work highlights how manipulating electronic interactions between energetic materials and their supports contributes to the design of high-energy-density yet safe energetic materials for miniaturized detonation devices.
{"title":"Balancing the Trade-Off Between Detonation Power and Safety by Spatially Anchoring Copper Azide on Nitrogen-Doped Reduced Graphene Oxide","authors":"Lei Zhang, Xu-Yang Wang, Li Yang, Haozhi Wang, Qian-You Wang","doi":"10.1002/smll.202500341","DOIUrl":"https://doi.org/10.1002/smll.202500341","url":null,"abstract":"Developing an effective tailoring approach to overcome the intrinsic trade-off between detonation power and safety in energetic materials is crucial for micro-electromechanical detonation systems but remains challenging. Herein, the anchoring of the high-energy-density yet highly sensitive primary explosive copper azide (CA) onto an N-doped reduced graphene oxide (NrGO) shell (denoted as CA@NrGO) is reported via electronic interactions. This approach simultaneously achieves a three-fold enhancement in mechanical safety, a ≈36-fold improvement in electrostatic safety compared to pure CA, and high detonation capacity. Theoretical calculations reveal that the electronic interaction between NrGO and CA not only facilitate energy dissipation from mechanical forces acting on CA—via intralayer compression and slip, thereby enhancing mechanical safety—but also promote interfacial electron transfer from CA to NrGO, preventing charge accumulation in CA and improving electrostatic safety. Furthermore, the excellent detonation power of CA@NrGO is demonstrated in a micro-detonation device, where 6 mg of CA@NrGO reliably initiated 20 mg of the secondary explosive CL-20. This work highlights how manipulating electronic interactions between energetic materials and their supports contributes to the design of high-energy-density yet safe energetic materials for miniaturized detonation devices.","PeriodicalId":228,"journal":{"name":"Small","volume":"32 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654211","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}
S. Charis Caroline, Athulya Ravindran, Kaushik Ghosh, Sudip K Batabyal
The unparalleled morphological tuning of layered double hydroxides (LDHs), specifically NiCo(OH)2, through fluorine doping, is systematically investigated. The unique morphological tuning is achieved by precisely modulating the fluorine dopant concentration using a straightforward solvothermal approach. Field Emission Scanning Electron Microscopy (FESEM) results show distinct succulent-like morphologies in the samples, influencing the surface area and electrochemical performance. Electrochemical studies of the fabricated asymmetric supercapacitor consisting of 2F-NiCo(OH)2|Activated Carbon(AC) electrodes exhibit very high charge storage capacity as high as 402 C g−1. Further, the X-ray photoelectron spectroscopy analysis confirms the incorporation and chemisorption of fluorine within the LDH layers, thereby corroborating its presence influencing the electronic environment and enhancing the electrochemical performance. The device shows an exceptionally high energy density, of 67 Wh kg−1 with power density of 10.6 kW kg−1 while retaining 95% specific capacity after 13 000 cycles at 10 mA cm−2 current density. The practical applicability of the developed supercapacitor is demonstrated by successfully powering an LED and a calculator, underscoring its potential for real-world energy storage solutions.
{"title":"Growth of Succulent Shaped Fluorine Incorporated Ni─Co LDH (F-NiCo(OH)2): Elevating Supercapacitor Efficiency","authors":"S. Charis Caroline, Athulya Ravindran, Kaushik Ghosh, Sudip K Batabyal","doi":"10.1002/smll.202411641","DOIUrl":"https://doi.org/10.1002/smll.202411641","url":null,"abstract":"The unparalleled morphological tuning of layered double hydroxides (LDHs), specifically NiCo(OH)<sub>2</sub>, through fluorine doping, is systematically investigated. The unique morphological tuning is achieved by precisely modulating the fluorine dopant concentration using a straightforward solvothermal approach. Field Emission Scanning Electron Microscopy (FESEM) results show distinct succulent-like morphologies in the samples, influencing the surface area and electrochemical performance. Electrochemical studies of the fabricated asymmetric supercapacitor consisting of 2F-NiCo(OH)<sub>2</sub>|Activated Carbon(AC) electrodes exhibit very high charge storage capacity as high as 402 C g<sup>−1</sup>. Further, the X-ray photoelectron spectroscopy analysis confirms the incorporation and chemisorption of fluorine within the LDH layers, thereby corroborating its presence influencing the electronic environment and enhancing the electrochemical performance. The device shows an exceptionally high energy density, of 67 Wh kg<sup>−1</sup> with power density of 10.6 kW kg<sup>−1</sup> while retaining 95% specific capacity after 13 000 cycles at 10 mA cm<sup>−2</sup> current density. The practical applicability of the developed supercapacitor is demonstrated by successfully powering an LED and a calculator, underscoring its potential for real-world energy storage solutions.","PeriodicalId":228,"journal":{"name":"Small","volume":"102 1 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654214","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}
Zhi-Xiang Yin, Hao Chen, Sheng-Feng Yin, Dan Zhang, Xin-Gui Tang, Vellaisamy A L Roy, Qi-Jun Sun
Memristors and artificial synapses have attracted tremendous attention due to their promising potential for application in the field of neural morphological computing, but at the same time, continuous optimization and improvement in energy consumption are also highly desirable. In recent years, it has been demonstrated that heterojunction is of great significance in improving the energy consumption of memristors and artificial synapses. By optimizing the material composition, interface characteristics, and device structure of heterojunctions, energy consumption can be reduced, and performance stability and durability can be improved, providing strong support for achieving low-power neural morphological computing systems. Herein, we review the recent progress on heterojunction-based memristors and artificial synapses by summarizing the working mechanisms and recent advances in heterojunction memristors, in terms of material selection, structure design, fabrication techniques, performance optimization strategies, etc. Then, the applications of heterojunction-based artificial synapses in neuromorphological computing and deep learning are introduced and discussed. After that, the remaining bottlenecks restricting the development of heterojunction-based memristors and artificial synapses are introduced and discussed in detail. Finally, corresponding strategies to overcome the remaining challenges are proposed. We believe this review may shed light on the development of high-performance memristors and artificial synapse devices.
{"title":"Recent Progress on Heterojunction-Based Memristors and Artificial Synapses for Low-Power Neural Morphological Computing","authors":"Zhi-Xiang Yin, Hao Chen, Sheng-Feng Yin, Dan Zhang, Xin-Gui Tang, Vellaisamy A L Roy, Qi-Jun Sun","doi":"10.1002/smll.202412851","DOIUrl":"https://doi.org/10.1002/smll.202412851","url":null,"abstract":"Memristors and artificial synapses have attracted tremendous attention due to their promising potential for application in the field of neural morphological computing, but at the same time, continuous optimization and improvement in energy consumption are also highly desirable. In recent years, it has been demonstrated that heterojunction is of great significance in improving the energy consumption of memristors and artificial synapses. By optimizing the material composition, interface characteristics, and device structure of heterojunctions, energy consumption can be reduced, and performance stability and durability can be improved, providing strong support for achieving low-power neural morphological computing systems. Herein, we review the recent progress on heterojunction-based memristors and artificial synapses by summarizing the working mechanisms and recent advances in heterojunction memristors, in terms of material selection, structure design, fabrication techniques, performance optimization strategies, etc. Then, the applications of heterojunction-based artificial synapses in neuromorphological computing and deep learning are introduced and discussed. After that, the remaining bottlenecks restricting the development of heterojunction-based memristors and artificial synapses are introduced and discussed in detail. Finally, corresponding strategies to overcome the remaining challenges are proposed. We believe this review may shed light on the development of high-performance memristors and artificial synapse devices.","PeriodicalId":228,"journal":{"name":"Small","volume":"43 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654166","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}
Ke Kong, Zhibin Cheng, Xueping Meng, Fangling Cui, Jiayu Huang, Dan Wang, Ruihu Wang, Xiaoju Li
The construction of the freestanding cathodes with high sulfur loading is one of the key approaches to achieve high-energy-density lithium–sulfur (Li–S) batteries. However, these freestanding sulfur cathodes often face challenges including low sulfur utilization, poor rate capability, and low cycling stability. Herein, a highly conductive freestanding sulfur cathode based on carbon fiber paper (CFP) and vanadium nitride (VN) nanowires array is reported. The uniformly distributed VN nanowires on CFP can effectively interact with sulfur species akin to ropes, which not only suppresses the polysulfides shuttling effect but also facilitates catalytic conversion of polysulfides. Additionally, the closely adhered VN nanowires on CFP support Li+ transport without hindrance, leveraging their high conductivity to promote redox kinetics. Therefore, the freestanding sulfur cathodes exhibit stable cycling performance even under high sulfur loading of 7.0 mg cm−2, a high areal capacity of 7.8 mA h cm−2 is achieved. This work provides valuable approaches to the assembly of freestanding sulfur electrodes for high-energy-density and long-lifetime Li–S batteries.
{"title":"Vanadium Nitride Nanowires Array on Carbon Nanofiber Paper for Regulating Polysulfides Toward Stable Freestanding Sulfur Cathode","authors":"Ke Kong, Zhibin Cheng, Xueping Meng, Fangling Cui, Jiayu Huang, Dan Wang, Ruihu Wang, Xiaoju Li","doi":"10.1002/smll.202412586","DOIUrl":"https://doi.org/10.1002/smll.202412586","url":null,"abstract":"The construction of the freestanding cathodes with high sulfur loading is one of the key approaches to achieve high-energy-density lithium–sulfur (Li–S) batteries. However, these freestanding sulfur cathodes often face challenges including low sulfur utilization, poor rate capability, and low cycling stability. Herein, a highly conductive freestanding sulfur cathode based on carbon fiber paper (CFP) and vanadium nitride (VN) nanowires array is reported. The uniformly distributed VN nanowires on CFP can effectively interact with sulfur species akin to ropes, which not only suppresses the polysulfides shuttling effect but also facilitates catalytic conversion of polysulfides. Additionally, the closely adhered VN nanowires on CFP support Li<sup>+</sup> transport without hindrance, leveraging their high conductivity to promote redox kinetics. Therefore, the freestanding sulfur cathodes exhibit stable cycling performance even under high sulfur loading of 7.0 mg cm<sup>−2</sup>, a high areal capacity of 7.8 mA h cm<sup>−2</sup> is achieved. This work provides valuable approaches to the assembly of freestanding sulfur electrodes for high-energy-density and long-lifetime Li–S batteries.","PeriodicalId":228,"journal":{"name":"Small","volume":"12 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654171","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}
Tingting Liu, Yuyu Liu, Ruting Lin, Chen Chen, Zonghua Pu, Yuzhi Sun, Shengyun Huang, Qingjun Chen, Abdullah M. Al-Enizi, Ayman Nafady, Mohd Ubaidullah, Xueqin Mu, Qiufeng Huang, Shichun Mu
The exploration and elucidation of the active site of catalysts is crucial for advancing the comprehension of the catalytic mechanism and propelling the development of exceptional catalysts. Herein, it is unveiled that anionic Si and cationic Pt in platinum silicide (PtSi) intermetallic compounds, obtained by ultrafast Joule heating (PtSi JH), simultaneously function as dual active sites for the hydrogen evolution reaction (HER). Density functional theory calculations reveal that, when both Pt and Si simultaneously serve as the active sites, the Gibbs free energy of hydrogen adsorption is 0.70 eV, significantly lower than that of either Pt (1.14 eV) or Si (0.90 eV) alone. Furthermore, both Pt-H and Si-H species are monitored by in situ Raman during the HER process. Consequently, PtSi JH exhibits ultralow overpotentials of 14, 30, and 51 mV at current densities of 10, 50, and 100 mA cm−2, respectively, outperorming commercial Pt/C and Si powder. More importantly, the Joule heating method represents a versatile approach for synthesizing a range of metal silicides including RhSi, RuSix, and Pd2Si. Therefore, this work opens a new avenue for the identification of genuine active sites and explores promising metal silicide for HER electrocatalysis and beyond.
{"title":"Ultrafast Carbothermal Shock Synthesis of Intermetallic Silicides with Anion-Cation Double Active Sites for Efficient Hydrogen Evolution","authors":"Tingting Liu, Yuyu Liu, Ruting Lin, Chen Chen, Zonghua Pu, Yuzhi Sun, Shengyun Huang, Qingjun Chen, Abdullah M. Al-Enizi, Ayman Nafady, Mohd Ubaidullah, Xueqin Mu, Qiufeng Huang, Shichun Mu","doi":"10.1002/smll.202412528","DOIUrl":"https://doi.org/10.1002/smll.202412528","url":null,"abstract":"The exploration and elucidation of the active site of catalysts is crucial for advancing the comprehension of the catalytic mechanism and propelling the development of exceptional catalysts. Herein, it is unveiled that anionic Si and cationic Pt in platinum silicide (PtSi) intermetallic compounds, obtained by ultrafast Joule heating (PtSi JH), simultaneously function as dual active sites for the hydrogen evolution reaction (HER). Density functional theory calculations reveal that, when both Pt and Si simultaneously serve as the active sites, the Gibbs free energy of hydrogen adsorption is 0.70 eV, significantly lower than that of either Pt (1.14 eV) or Si (0.90 eV) alone. Furthermore, both Pt-H and Si-H species are monitored by in situ Raman during the HER process. Consequently, PtSi JH exhibits ultralow overpotentials of 14, 30, and 51 mV at current densities of 10, 50, and 100 mA cm<sup>−2</sup>, respectively, outperorming commercial Pt/C and Si powder. More importantly, the Joule heating method represents a versatile approach for synthesizing a range of metal silicides including RhSi, RuSi<sub>x</sub>, and Pd<sub>2</sub>Si. Therefore, this work opens a new avenue for the identification of genuine active sites and explores promising metal silicide for HER electrocatalysis and beyond.","PeriodicalId":228,"journal":{"name":"Small","volume":"19 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654177","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}
Frontier orbital hybridization plays a vital role in the initial adsorption and activation process during catalysis. A formidable challenge is the precise determination of active orbitals/sites. Herein, 2D Bi3O4Br nanosheets are adopted as an operable platform for heteroatom doping of various transition metals (Fe, Ni, Zn/Cd). As the atom number of dopants increases, the capability of selective CO2 photoconversion is continuously amplified. The intrinsic nature is the variation of active functional orbital as indicated from band center distance (Δd/p-p) indicators. The calculated charge transfer of various CO2-bound geometries further demonstrates the p-p orbital interaction overwhelms d-p orbital interaction. X-ray photoelectron spectroscopy and X-ray absorption spectroscopy results verify the charged nature of Bi sites with 6p orbitals not fully filled by electrons. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis and Gibbs free energy change profile suggest the rapid emergence of the critical *COOH intermediate in a thermodynamically preferred pathway.
{"title":"Elucidating the Functional Orbital Evolution in Transition Metal-Doped Bi3O4Br Platforms for CO2 Photoreduction","authors":"Xiaoyang Yue, Chen Guan, Hui Yang, Minshu Chen, Quanjun Xiang","doi":"10.1002/smll.202412527","DOIUrl":"https://doi.org/10.1002/smll.202412527","url":null,"abstract":"Frontier orbital hybridization plays a vital role in the initial adsorption and activation process during catalysis. A formidable challenge is the precise determination of active orbitals/sites. Herein, 2D Bi<sub>3</sub>O<sub>4</sub>Br nanosheets are adopted as an operable platform for heteroatom doping of various transition metals (Fe, Ni, Zn/Cd). As the atom number of dopants increases, the capability of selective CO<sub>2</sub> photoconversion is continuously amplified. The intrinsic nature is the variation of active functional orbital as indicated from band center distance (Δ<i>d/p-p</i>) indicators. The calculated charge transfer of various CO<sub>2</sub>-bound geometries further demonstrates the <i>p-p</i> orbital interaction overwhelms <i>d-p</i> orbital interaction. X-ray photoelectron spectroscopy and X-ray absorption spectroscopy results verify the charged nature of Bi sites with <i>6p</i> orbitals not fully filled by electrons. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis and Gibbs free energy change profile suggest the rapid emergence of the critical <sup>*</sup>COOH intermediate in a thermodynamically preferred pathway.","PeriodicalId":228,"journal":{"name":"Small","volume":"19 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640996","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}
The efficiency of proton exchange membrane electrolysis cells (PEMECs) is much influenced by the dynamics of gas/liquid two-phase flow at the anode side, especially at high current densities. Among different components of PEMECs, the anode porous transport layers (PTLs) are essential for mass transfer optimization. In this work, novel titanium fiber PTLs are designed and fabricated by an angle-selective stacking method. Three oriented PTLs with 30°, 60°, and 90° stacking angles are fabricated and compared with commercial titanium felt. X-ray micro-computed tomography results indicate that the oriented PTLs can avoid dead zones. Electrochemical tests and computational fluid dynamics simulations demonstrate that the oriented PTLs can enhance oxygen expulsion, and decrease mass transport resistances at high current densities. The PEMEC with the 30° PTL exhibits the best performance, with polarization voltage and mass transport resistance decreased by ≈67 mV and 16 mΩ cm2, respectively, compared to that of the commercial titanium felt at the current density of 3 A cm−2. The current work provides a new perspective on enhancing the mass transport efficiency of PTLs by orderly arranging fibers.
{"title":"Enhancing Mass Transport Efficiency in High-Current Density PEMECs by Constructing Ti-Fiber Oriented Porous Transport Layers","authors":"Zhaolun Zhu, Xiaolong Liu, Rui Gao, Rongyu Yang, Muyu Ma, Hongwu Zhao, Yongli Li","doi":"10.1002/smll.202411817","DOIUrl":"https://doi.org/10.1002/smll.202411817","url":null,"abstract":"The efficiency of proton exchange membrane electrolysis cells (PEMECs) is much influenced by the dynamics of gas/liquid two-phase flow at the anode side, especially at high current densities. Among different components of PEMECs, the anode porous transport layers (PTLs) are essential for mass transfer optimization. In this work, novel titanium fiber PTLs are designed and fabricated by an angle-selective stacking method. Three oriented PTLs with 30°, 60°, and 90° stacking angles are fabricated and compared with commercial titanium felt. X-ray micro-computed tomography results indicate that the oriented PTLs can avoid dead zones. Electrochemical tests and computational fluid dynamics simulations demonstrate that the oriented PTLs can enhance oxygen expulsion, and decrease mass transport resistances at high current densities. The PEMEC with the 30° PTL exhibits the best performance, with polarization voltage and mass transport resistance decreased by ≈67 mV and 16 mΩ cm<sup>2</sup>, respectively, compared to that of the commercial titanium felt at the current density of 3 A cm<sup>−2</sup>. The current work provides a new perspective on enhancing the mass transport efficiency of PTLs by orderly arranging fibers.","PeriodicalId":228,"journal":{"name":"Small","volume":"17 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640984","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}
Precisely modulating d-p orbital coupling of single-atom electrocatalysts for sulfur reduction reactions in lithium-sulfur batteries maintains tremendous challenges. Herein, a dynamic d-p-π orbital coupling modulation is elucidated by unsaturated Fe centers on nitrogen-doped graphitized carbon (NG) coordinated with trithiocyanuric acid featuring with p-π conjugation to engineer Fe single atom architecture (FeN4-Spπ-NG). Intriguingly, this coordination microenvironment of the Fe center is dynamically reconstituted during charge/discharge processes, because of the formation of trilithium salts rooted from the departed axial ligands to engineer interfacial coating on the sulfur cathode, and then it recovers to the initial coordination configuration. Theoretical and experimental results unravel that the axial p-π conjugated ligand reinforcing d-p orbital coupling enables the interfacial charge interaction, thereby strengthening LiPSs adsorption, and reducing the Li2S decomposition barrier by formation of Fe─S and S─Li bonds. Thus, dynamic d-p-π orbital coupling modulation of FeN4-Spπ endow lithium-sulfur batteries with considerable electrochemical performances, highlighting an intriguingly dynamic orbital coupling modulation strategy for single atom electrocatalysts.
{"title":"Dynamic D-p-π Orbital Coupling of FeN4-Spπ Atomic Centers on Graphitized Carbon Toward Invigorated Sulfur Kinetic Chemistry","authors":"Xinlu Zhang, Zhengran Wang, Chuanliang Wei, Baojuan Xi, Shenglin Xiong, Jinkui Feng","doi":"10.1002/smll.202412394","DOIUrl":"https://doi.org/10.1002/smll.202412394","url":null,"abstract":"Precisely modulating d-p orbital coupling of single-atom electrocatalysts for sulfur reduction reactions in lithium-sulfur batteries maintains tremendous challenges. Herein, a dynamic d-p-π orbital coupling modulation is elucidated by unsaturated Fe centers on nitrogen-doped graphitized carbon (NG) coordinated with trithiocyanuric acid featuring with p-π conjugation to engineer Fe single atom architecture (Fe<sub>N4-</sub>S<sub>pπ</sub>-NG). Intriguingly, this coordination microenvironment of the Fe center is dynamically reconstituted during charge/discharge processes, because of the formation of trilithium salts rooted from the departed axial ligands to engineer interfacial coating on the sulfur cathode, and then it recovers to the initial coordination configuration. Theoretical and experimental results unravel that the axial p-π conjugated ligand reinforcing d-p orbital coupling enables the interfacial charge interaction, thereby strengthening LiPSs adsorption, and reducing the Li<sub>2</sub>S decomposition barrier by formation of Fe─S and S─Li bonds. Thus, dynamic d-p-π orbital coupling modulation of Fe<sub>N4</sub>-S<sub>pπ</sub> endow lithium-sulfur batteries with considerable electrochemical performances, highlighting an intriguingly dynamic orbital coupling modulation strategy for single atom electrocatalysts.","PeriodicalId":228,"journal":{"name":"Small","volume":"87 1","pages":""},"PeriodicalIF":13.3,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640998","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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