Nanomaterials最新文献

{"title":"Studying the Defects in Spinel Compounds: Discovery, Formation Mechanisms, Classification, and Influence on Catalytic Properties.","authors":"Tetiana Tatarchuk","doi":"10.3390/nano14201640","DOIUrl":"https://doi.org/10.3390/nano14201640","url":null,"abstract":"<p><p>Spinel ferrites demonstrate extensive applications in different areas, like electrodes for electrochemical devices, gas sensors, catalysts, and magnetic adsorbents for environmentally important processes. However, defects in the real spinel structure can change the many physical and chemical properties of spinel ferrites. Although the number of defects in a crystal spinel lattice is small, their influence on the vast majority of physical properties could be really decisive. This review provides an overview of the structural characteristics of spinel compounds (e.g., CoFe₂O₄, NiFe₂O₄, ZnFe₂O₄, Fe₃O₄, γ-Fe₂O₃, Co₃O₄, Mn₃O₄, NiCo₂O₄, ZnCo₂O₄, Co₂MnO₄, etc.) and examines the influence of defects on their properties. Attention was paid to the classification (0D, 1D, 2D, and 3D defects), nomenclature, and the formation of point and surface defects in ferrites. An in-depth description of the defects responsible for the physicochemical properties and the methodologies employed for their determination are presented. DFT as the most common simulation approach is described in relation to modeling the point defects in spinel compounds. The significant influence of defect distribution on the magnetic interactions between cations, enhancing magnetic properties, is highlighted. The main defect-engineering strategies (direct synthesis and post-treatment) are described. An antistructural notation of active centers in spinel cobalt ferrite is presented. It is shown that the introduction of cations with different charges (e.g., Cu(I), Mn(II), Ce(III), or Ce(IV)) into the cobalt ferrite spinel matrix results in the formation of various point defects. The ability to predict the type of defects and their impact on material properties is the basis of defect engineering, which is currently an extremely promising direction in modern materials science.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510202/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Synthesis Parameters on Structure and Characteristics of the Graphene Grown Using PECVD on Sapphire Substrate.","authors":"Šarūnas Jankauskas, Šarūnas Meškinis, Nerija Žurauskienė, Asta Guobienė","doi":"10.3390/nano14201635","DOIUrl":"https://doi.org/10.3390/nano14201635","url":null,"abstract":"<p><p>The high surface area and transfer-less growth of graphene on dielectric materials is still a challenge in the production of novel sensing devices. We demonstrate a novel approach to graphene synthesis on a C-plane sapphire substrate, involving the microwave plasma-enhanced chemical vapor deposition (MW-PECVD) technique. The decomposition of methane, which is used as a precursor gas, is achieved without the need for remote plasma. Raman spectroscopy, atomic force microscopy and resistance characteristic measurements were performed to investigate the potential of graphene for use in sensing applications. We show that the thickness and quality of graphene film greatly depend on the CH₄/H₂ flow ratio, as well as on chamber pressure during the synthesis. By varying these parameters, the intensity ratio of Raman D and G bands of graphene varied between ~1 and ~4, while the 2D to G band intensity ratio was found to be 0.05-0.5. Boundary defects are the most prominent defect type in PECVD graphene, giving it a grainy texture. Despite this, the samples exhibited sheet resistance values as low as 1.87 kΩ/□. This reveals great potential for PECVD methods and could contribute toward efficient and straightforward graphene growth on various substrates.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11509920/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of ZrO₂ Nano-Particles' Incorporation into SnAgCu Solder Alloys: An Experimental and Theoretical Study.","authors":"Agata Skwarek, Halim Choi, Tamás Hurtony, Jaeduk Byun, Ahmad Azmin Mohamad, David Bušek, Karel Dušek, Balázs Illés","doi":"10.3390/nano14201636","DOIUrl":"https://doi.org/10.3390/nano14201636","url":null,"abstract":"<p><p>This study investigates the mechanism and effects of incorporating different ZrO₂ nano-particles into SAC0307 solder alloys. ZrO₂ nano-powder and nano-fibers in 0.25-0.5 wt% were added to the SAC0307 alloy to prepare composite solder joints by surface mount technology. The solder joints were shear tested before and after a 4000 h long 85 °C/85% RH corrosive reliability test. The incorporation of ZrO₂ nano-particles enhanced the initial shear force of the solder joint, but they decreased the corrosion resistance in the case of 0.5 wt%. SEM, EDS, and FIB analysis revealed intensive growth of SnO₂ on the solder joint surfaces, leading to the formation of Sn whiskers. Density functional theory (DFT) simulations showed that, despite Sn being able to bond to the surface of ZrO₂, the binding energy was weak, and the whole system was therefore unstable. It was also found that ZrO₂ nano-particles refined the microstructure of the solder joints. Decreased β-Sn grain size and more dispersed intermetallic compounds were observed. The microstructural refinement caused mechanical improvement of the ZrO₂ composite solder joints by dispersion strengthening but could also decrease their corrosion resistance. While ZrO₂ nano-particles improved the solder joint mechanical properties, their use is recommended only in non-corrosive environments, such as microelectronics for space applications.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510246/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Bis(4-aminophenoxy) Benzene-Based Aramid Copolymers with Enhanced Solution Processability.","authors":"Wonseong Song, Amol M Jadhav, Yeonhae Ryu, Soojin Kim, Jaemin Im, Yujeong Jeong, Vanessa, Youngjin Kim, Yerin Sung, Yuri Kim, Hyun Ho Choi","doi":"10.3390/nano14201632","DOIUrl":"https://doi.org/10.3390/nano14201632","url":null,"abstract":"<p><p>Aramid copolymers have garnered significant interest due to their potential applications in extreme environments such as the aerospace, defense, and automotive industries. Recent developments in aramid copolymers have moved beyond their traditional use in high-strength, high-temperature resistant fibers. There is now a demand for new polymers that can easily be processed into thin films for applications such as electrical insulation films and membranes, utilizing the inherent properties of aramid copolymers. In this work, we demonstrate two novel aramid copolymers that are capable of polymerizing in polar organic solvents with a high degree of polymerization, achieved by incorporating flexible bis(4-aminophenoxy) benzene moieties into the chain backbone. The synthesized MBAB-aramid and PBAB-aramid have enabled the fabrication of exceptionally thin, clear films, with an average molecular weight exceeding 150 kDa and a thickness ranging from 3 to 10 μm. The dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) reveal that the thin films of MBAB-aramid and PBAB-aramid exhibited glass transition temperatures of 270.1 °C and 292.7 °C, respectively, and thermal decomposition temperatures of 449.6 °C and 465.5 °C, respectively. The mechanical tensile analysis of the 5 μm thick films confirmed that the tensile strengths, with elongation at break, are 107.1 MPa (50.7%) for MBAB-aramid and 113.5 MPa (58.4%) for PBAB-aramid, respectively. The thermal and mechanical properties consistently differ between the two polymers, which is attributed to variations in the linearity of the polymer structures and the resulting differences in the density of intermolecular hydrogen bonding and pi-pi interactions. The resulting high-strength, ultra-thin aramid materials offer numerous potential applications in thin films, membranes, and functional coatings across various industries.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510568/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Nanomaterials in Biomedical Imaging and Cancer Therapy II.","authors":"James C L Chow","doi":"10.3390/nano14201627","DOIUrl":"https://doi.org/10.3390/nano14201627","url":null,"abstract":"<p><p>Following the successful publication of the first edition of our Special Issue entitled \"Application of Nanomaterials in Biomedical Imaging and Cancer Therapy\" [...].</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510138/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure Evolution of the Interface in SiC_f/TiC-Ti₃SiC₂ Composite under Sequential Xe-He-H Ion Irradiation and Annealing Process.","authors":"Penghui Lei, Qing Chang, Mingkun Xiao, Chao Ye, Pan Qi, Fangjie Shi, Yuhua Hang, Qianwu Li, Qing Peng","doi":"10.3390/nano14201629","DOIUrl":"https://doi.org/10.3390/nano14201629","url":null,"abstract":"<p><p>A new type of SiC_f/TiC-Ti₃SiC₂ composite was prepared by the Spark Plasma Sintering (SPS) method in this work. The phase transformation and interface cracking of this composite under ion irradiation (single Xe, Xe + He, and Xe + He + H ions) and subsequent annealing were analyzed using transmission electron microscopy (TEM), mainly focusing on the interface regions. Xe ion irradiation resulted in the formation of high-density stacking faults in the TiC coatings and the complete amorphization of SiC fibers. The implanted H ions exacerbated interface coarsening. After annealing at 900 °C for 2 h, the interface in the Xe + He + H ion-irradiated samples was seriously damaged, resulting in the formation of large bubbles and cracks. This damage occurred because the H atoms reduced the surface free energy, thereby promoting the nucleation and growth of bubbles. Due to the absorption effect of the SiC_f/TiC interface on defects, the SiC fiber areas near the interface recovered back to the initial nano-polycrystalline structure after annealing.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510621/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: Dulski et al. An Organic-Inorganic Hybrid Nanocomposite as a Potential New Biological Agent. <i>Nanomaterials</i> 2020, <i>10</i>, 2551.","authors":"Mateusz Dulski, Katarzyna Malarz, Michał Kuczak, Karolina Dudek, Krzysztof Matus, Sławomir Sułowicz, Anna Mrozek-Wilczkiewicz, Anna Nowak","doi":"10.3390/nano14201626","DOIUrl":"https://doi.org/10.3390/nano14201626","url":null,"abstract":"<p><p>In the original publication [...].</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11509919/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced Photoelectrochemical Water Splitting of In₂S₃ Photoanodes by Surface Modulation with 2D MoS₂ Nanosheets.","authors":"Roshani Awanthika Jayarathna, Jun-Ho Heo, Eui-Tae Kim","doi":"10.3390/nano14201628","DOIUrl":"https://doi.org/10.3390/nano14201628","url":null,"abstract":"<p><p>Photoanodes with ample visible-light absorption and efficient photogenerated charge carrier dynamics expedite the actualization of high-efficiency photoelectrochemical water splitting (PEC-WS). Herein, we fabricated the heterojunction nanostructures of In₂S₃/MoS₂ on indium-doped tin oxide glass substrates by indium sputtering and sulfurization, followed by the metal-organic chemical vapor deposition of 2D MoS₂ nanosheets (NSs). The photocurrent density of In₂S₃/MoS₂ was substantially enhanced and higher than those of pristine In₂S₃ and MoS₂ NSs. This improvement is due to the MoS₂ NSs extending the visible-light absorption range and the type-II heterojunction enhancing the separation and transfer of photogenerated electron-hole pairs. This work offers a promising avenue toward the development of an efficient photoanode for solar-driven PEC-WS.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11509911/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Honeycomb Cell Structures Formed in Drop-Casting CNT Films for Highly Efficient Solar Absorber Applications.","authors":"Saiful Islam, Hiroshi Furuta","doi":"10.3390/nano14201633","DOIUrl":"https://doi.org/10.3390/nano14201633","url":null,"abstract":"<p><p>This study investigates the process of using multi-walled carbon nanotube (MWCNT) coatings to enhance lamp heating temperatures for solar thermal absorption applications. The primary focus is studying the effects of the self-organized honeycomb structures of CNTs formed on silicon substrates on different cell area ratios (CARs). The drop-casting process was used to develop honeycomb-structured MWCNT-coated absorbers with varying CAR values ranging from ~60% to 17%. The optical properties were investigated within the visible (400-800 nm) and near-infrared (934-1651 nm) wavelength ranges. Although fully coated MWCNT absorbers showed the lowest reflectance, honeycomb structures with a ~17% CAR achieved high-temperature absorption. These structures maintained 8.4% reflectance at 550 nm, but their infrared reflection dramatically increased to 80.5% at 1321 nm. The solar thermal performance was assessed throughout a range of irradiance intensities, from 0.04 W/cm² to 0.39 W/cm². The honeycomb structure with a ~17% CAR value consistently performed better than the other structures by reaching the highest absorption temperatures (ranging from 52.5 °C to 285.5 °C) across all measured intensities. A direct correlation was observed between the reflection ratio (visible: 550 nm/infrared: 1321 nm) and the temperature absorption efficiency, where lower reflection ratios were associated with higher temperature absorption. This study highlights the significant potential for the large-scale production of cost-effective solar thermal absorbers through the application of optimized honeycomb-structured absorbers coated with MWCNTs. These contributions enhance solar energy efficiency for applications in water heating and purification, thereby promoting sustainable development.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510551/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Efficient Organic/Silicon Hybrid Solar Cells with a MoO₃ Capping Layer.","authors":"Jiahui Chen, Zhangbo Lu, Xiaoting Wang, Yuner Luo, Yun Ma, Gang Lou, Dan Chi, Shihua Huang","doi":"10.3390/nano14201630","DOIUrl":"https://doi.org/10.3390/nano14201630","url":null,"abstract":"<p><p>Organic/Si hybrid solar cells have attracted considerable attention for their uncomplicated fabrication process and superior device efficiency, making them a promising candidate for sustainable energy applications. However, the efficient collection and separation of charge carriers at the organic/Si heterojunction interface are primarily hindered by the inadequate work function of poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS). Here, the application of a high-work-function MoO₃ film onto the n-Si/PEDOT:PSS surface leads to a notable enhancement in the device's built-in potential. This enhancement results in the creation of an inversion layer near the n-Si surface and facilitates charge separation at the interface. Simultaneously, it inhibits charge recombination at the heterojunction interface. As a result, the champion PEDOT:PSS/Si solar cell, which incorporates a MoO₃ interface layer, demonstrates an efficiency of 16.0% and achieves a high fill factor of 80.8%. These findings provide a straightforward and promising strategy for promoting the collection and transmission of charge carriers at the interface of photovoltaic devices.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11510610/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142516483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}