Nanomaterials最新文献

{"title":"The Solvothermal Method: An Efficient Tool for the Preparation of Ni-Based Catalysts with High Activity in CO₂ Methanation.","authors":"Arkadii Bikbashev, Tomáš Stryšovský, Martina Kajabová, Zuzana Kovářová, Arati Prakash Tibe, Karolína Simkovičová, Robert Prucek, Aleš Panáček, Josef Kašlík, Patrizia Frontera, Kouřil Roman, Arian Grainca, Carlo Pirola, Libor Brabec, Zdeněk Bastl, Štefan Vajda, Libor Kvítek","doi":"10.3390/nano15171379","DOIUrl":"10.3390/nano15171379","url":null,"abstract":"<p><p>Nickel and nickel oxide are widely used as heterogeneous catalysts in various processes involving the hydrogenation or reduction of organic compounds, and also as excellent methanation catalysts in the hydrogenation of CO₂. As heterogeneous catalysis is a surface-dependent process, nickel compounds in the form of microparticles (MPs), and particularly nanoparticles (NPs), improve the catalytic activity of Ni-based catalysts due to their high specific surface area. Solvothermal synthesis, which has so far been neglected for the synthesis of Ni-based methanation catalysts, was used in this study to synthesize nickel and nickel oxide MPs and NPs with a narrow size distribution. Solvothermal synthesis allows for the control of both the chemical composition of the resulting Ni catalysts and their physical structure by simply changing the reaction conditions (solvent, temperature, or concentration of reactants). Only non-toxic substances were used for synthesis in this study, meaning that the whole synthesis process can be described as environmentally friendly. Solvothermally prepared Ni compounds were subsequently transformed into nickel oxide by means of high-temperature decomposition, and all of the prepared Ni-based compounds were tested as catalysts for CO₂ methanation. The best catalysts prepared in this study exhibited a CO₂ conversion rate of nearly 95% and a selectivity for methane close to 100%, which represent thermodynamic limits for this reaction at the used temperature. These results are commonly achieved with much more complex catalytic composites containing precious metals, while here we worked with pure nickel and its oxides, in the form of micro- or nanoparticles, only.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430002/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040961","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":"Effect of Ultra-Small Platinum Single-Atom Additives on Photocatalytic Activity of the CuO_x-Dark TiO₂ System in HER.","authors":"Elena D Fakhrutdinova, Olesia A Gorbina, Olga V Vodyankina, Sergei A Kulinich, Valery A Svetlichnyi","doi":"10.3390/nano15171378","DOIUrl":"10.3390/nano15171378","url":null,"abstract":"<p><p>Improving the efficiency of photocatalysts for hydrogen production while minimizing the amount of noble metals used is a pressing issue in modern green energy. This study examines the effect of ultra-small Pt additives on increasing the efficiency of the CuO_x-dark TiO₂ photocatalyst used in the hydrogen evolution reaction (HER). Initially, Pt was photoreduced from the hydroxonitrate complex (Me₄N)₂[Pt₂(OH)₂(NO₃)₈] onto the surface of nanodispersed CuO_x powder obtained by pulsed laser ablation. Then, the obtained Pt-CuO_x particles were dispersed on the surface of highly defective dark TiO₂, so that the mass content of Pt in the samples varied in the range from 1.25 × 10^-5 to 10^-4. The prepared samples were examined using HRTEM, XRD, XPS, and UV-Vis DRS methods. It has been established that in the Pt-CuO_x particles, platinum is mainly present in the form of single atoms (SAs), both as Pt²⁺ (predominantly) and Pt⁴⁺ species, which should facilitate electron transfer and contribute to the manifestation of the strong metal-support interaction (SMSI) effect between SA Ptⁿ⁺ and CuO_x. In turn, in the Pt-CuO_x-dark TiO₂ samples, surface defects (O_v) and surface OH groups on dark TiO₂ particles act as \"anchors\", promoting the spontaneous dispersion of CuO_x in the form of sub-nanometer clusters with the reduction of Cu²⁺ to Cu¹⁺ when localized near such O_v defects. During photocatalytic HER in aqueous glycerol solutions, irradiation was found to initiate a large number of catalytically active Pt⁰-CuO_x-O_v-dark TiO₂ centers, where the SMSI effect causes electron transfer from titania to SA Pt, thus promoting better separation of photogenerated charges. As a result, ultra-small additives of Pt led to up to a 1.34-fold increase in the amount of released hydrogen, while the maximum apparent quantum yield (AQY) reached 65%.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12429992/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040668","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":"On-Chip OPA: Progress and Prospects in Liquid Crystal, Lithium Niobate, and Silicon Material Platforms.","authors":"Xiaobin Wang, Junliang Guo, Zixin Yang, Yuqiu Zhang, Jinyong Leng, Qiang Yu, Jian Wu","doi":"10.3390/nano15171374","DOIUrl":"10.3390/nano15171374","url":null,"abstract":"<p><p>Non-mechanical beam steering is required for holographic displays, free-space optical communication, and chip-scale LiDAR. Optical phased arrays (OPAs), which allow for inertia-free, high-speed beam control via electronic phase control, are an important research topic. The present study investigates the primary material platform for on-chip OPAs: Liquid crystal OPAs (LC-OPAs) employ electrically tunable refractive indices for low-voltage operation; lithium niobate OPAs (LN-OPAs) utilize high electro-optic coefficients for high-speed, low-power consumption, and large-bandwidth operation; and silicon-based OPAs (Si-OPAs) apply mature photonic integration to achieve high integration density and GHz-range steering. The paper thoroughly examines OPA basics, recent material-specific advancements, performance benchmarks, outstanding issues, and future prospects.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430256/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040753","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":"Albumin-Coated Copper Oxide Nanoparticles for Radiosensitization of Human Glioblastoma Cells Under Clinically Relevant X-Ray Irradiation.","authors":"Chanyatip Suwannasing, Nittiya Suwannasom, Pattawat Iamcharoen, Rachan Dokkham, Panupong Maun, Pitchayuth Srisai, Hans Bäumler, Ausanai Prapan","doi":"10.3390/nano15171376","DOIUrl":"10.3390/nano15171376","url":null,"abstract":"<p><p>Glioblastoma (GBM) is the most aggressive and treatment-resistant primary brain tumor in adults. Despite current multimodal therapies, including surgery, radiation, and temozolomide chemotherapy, patient outcomes remain poor. Enhancing tumor radiosensitivity through biocompatible nanomaterials could provide a promising integrative strategy for improving therapeutic effectiveness. This study aims to evaluate the potential of bovine serum albumin-coated copper oxide nanoparticles (BSA@CuO-NPs) to enhance radiosensitivity in U87-MG cells under clinically relevant X-ray irradiation. In brief, BSA@CuO-NPs were synthesized via carbodiimide crosslinking and characterized by DLS, SEM, and zeta potential analysis. U87-MG cells were treated with BSA@CuO-NPs alone or in combination with X-ray irradiation (2 Gy). Cytotoxicity was assessed using the MTT assay, while radiosensitization was evaluated through clonogenic survival analysis. Apoptosis induction and DNA damage were analyzed via Annexin V staining and γ-H2AX immunofluorescence, respectively. The results revealed that BSA@CuO-NPs showed good colloidal stability and biocompatibility compared with uncoated CuO-NPs. When combined with irradiation, BSA@CuO-NPs significantly decreased clonogenic survival (<i>p</i> < 0.05) and increased apoptotic cell death compared to irradiation alone. Immunofluorescence demonstrated increased γ-H2AX focus formation, indicating higher DNA double-strand breaks in the combination group. In conclusion, BSA@CuO-NPs enhance the effects of ionizing radiation by increasing DNA damage and apoptosis in U87-MG cells, indicating their potential as combined radiosensitizers. These results support further research into albumin-coated metal oxide nanoparticles as adjuncts to standard radiotherapy for the management of GBM. One challenge in this context is the effective delivery of nanoparticles to GBM. However, the stability of BSA@CuO-NPs in physiological solutions could help overcome this obstacle.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430620/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040899","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":"Investigation of Viscoelastic Properties of Macrophage Membrane-Cytoskeleton Induced by Gold Nanorods in Leishmania Infection.","authors":"Maria L B Pertence, Marina V Guedes, Rosimeire C Barcelos, Jeronimo N Rugani, Rodrigo P Soares, Joyce L V Cruz, Alessandra M de Sousa, Rubens L do Monte-Neto, Livia G Siman, Anna C P Lage, Ubirajara Agero","doi":"10.3390/nano15171373","DOIUrl":"10.3390/nano15171373","url":null,"abstract":"<p><p>Cell membranes and the cytoskeleton play crucial roles in the regulation of cellular responses by mediating mechanical forces and physical stimuli from the microenvironment through their viscoelastic properties. Investigating these properties provides valuable insights into disease mechanisms and therapeutic strategies. Gold nanorods (GNRs), especially under irradiation, exhibit lethal effects against <i>Leishmania</i> parasites through plasmonic photothermal conversion. In this study, we focus on evaluating the effects of non-irradiated GNRs on macrophage properties to better understand their intrinsic interactions with cells and support the development of future phototherapy applications. Here, defocusing microscopy (DM), a quantitative phase microscopy technique, was used to analyze membrane fluctuations in macrophages (M&empty;s) exposed to GNRs (average length of 43±8 nm and diameter of 20±4 nm) and infected with <i>Leishmania amazonensis</i>. By quantifying membrane-cytoskeleton fluctuation from defocused images, we extracted viscoelastic parameters, including bending modulus (kc) and viscosity (η), to characterize membrane behavior in detail. Our results show that infection increases both kc and η, while treatment at IC₅₀ reduces infection and selectively increases kc without affecting η. In healthy macrophages, exposure to GNRs resulted in a reduction in both parameters, indicative of increased membrane fluidity and cytoskeletal rearrangement. These findings provide new insights into the biomechanical effects of GNRs on macrophages and may enlighten the design of future phototherapeutic approaches.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430347/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040806","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":"A Peano-Gosper Fractal-Inspired Stretchable Electrode with Integrated Three-Directional Strain and Normal Pressure Sensing.","authors":"Chunge Wang, Yuanyuan Huang, Zixia Zhao, Haoyu Li, Chen Liu, Zhixin Jia, Yanping Wang, Qianqian Wang, Sheng Zhang","doi":"10.3390/nano15171370","DOIUrl":"10.3390/nano15171370","url":null,"abstract":"<p><p>A novel stretchable flexible electrode capable of simultaneously detecting isotropic three-directional strain and normal pressure has been developed. Inspired by the recursive symmetry of the Peano-Gosper fractal, the electrode integrates liquid metal (EGaIn) microchannels within a PDMS matrix to achieve uniform strain distribution and mechanically robust conductive pathways under large deformation. Within a strain range of 0-60%, the electrode exhibits highly consistent three-directional responses, with resistance variation across axes kept below 4% and a gauge factor (<i>GF</i>) standard deviation of only 0.0252. The device demonstrates low hysteresis (minimum DH = 0.94%), good cyclic durability, and reliable electromechanical stability. For normal pressure sensing (0-20 kPa), it provides a linear response (<i>R</i>² ≈ 0.99) with a moderate sensitivity of 0.198 kPa^-1. Wearable tests on the wrist, finger, and fingertip confirm the electrode's reliable operation in multidimensional mechanical monitoring. This integrated fractal-liquid metal design offers a promising route for multifunctional sensing in applications such as soft robotics, human-machine interaction, and wearable electronics.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430592/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040901","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":"Comparative Evaluation of Antioxidant and Antidiabetic Activities of ZrO₂ and MgO Nanoparticles Biosynthesized from Unripe <i>Solanum trilobatum</i> Fruits: Insights from In Vitro and In Silico Studies.","authors":"Kumaresan Rathika, Periyanayagam Arockia Doss, John Rose Arul Hency Sheela, Velayutham Gurunathan, K J Senthil Kumar, Chidambaram Sathishkumar, Vediyappan Thirumal, Jinho Kim","doi":"10.3390/nano15171372","DOIUrl":"10.3390/nano15171372","url":null,"abstract":"<p><p>Herbs offer people not just sustenance and housing but also serve as a key supplier of pharmaceuticals. This research is designed to assess the antioxidant and antidiabetic properties of green-produced zirconium dioxide and magnesium oxide nanoparticles (ZrO₂ and MgO NPs) utilizing extracts from unripe <i>Solanum trilobatum</i> fruit. ZrO₂ and MgO NPs have garnered considerable interest owing to their superior bioavailability, lower toxicity, and many uses across the healthcare and commercial industries. Scientific approaches, such as diverse spectroscopic and microscopic approaches, validated the creation of agglomerated spherical ZrO₂ and MgO NPs, measuring between 15 and 30 and 60 and 80 nm, with a mixed-phase composition consisting of monoclinic and tetragonal phases for ZrO₂ and a face-centered cubic structure for MgO NPs. UV-vis studies revealed a distinct peak at 378 and 290 nm for ZrO₂ and MgO NPs, suggesting efficient settling through the phytonutrients in <i>S. trilobatum</i>. The antioxidant capacity of ZrO₂ and MgO NPs was evaluated utilizing DPPH and FRAP reducing power assays. The diabetic effectiveness of ZrO₂ and MgO NPs was examined by alpha-amylase and alpha-glucosidase assays. The optimum doses of 500 and 1000 μg/mL were shown to be efficient in reducing radical species. Green-produced ZrO₂ and MgO NPs exhibited a dose-dependent reaction, with greater amounts of ZrO₂ and MgO NPs exerting a more pronounced inhibitory effect on the catalytic sites of enzymes. This work suggests that ZrO₂ and MgO NPs may attach to charge-carrying entities and function as rival inhibitors, therefore decelerating the enzyme-substrate reaction and inhibiting enzymatic degradation. Molecular docking analysis of ZrO₂ and MgO NPs with three proteins (2F6D, 2QV4, and 3MNG) implicated in antidiabetic and antioxidant studies demonstrated the interaction of ZrO₂ and MgO NPs with the target proteins. The results indicated the in vitro effectiveness of phytosynthesized ZrO₂ and MgO NPs as antidiabetic antioxidant agents, which may be used in the formulation of alternative treatment strategies against diabetes and oxidative stress. In summary, the green production of ZrO₂ and MgO NPs with <i>Solanum trilobatum</i> unripe fruit extract is an efficient, environmentally sustainable process that yields nanomaterials with significant antioxidant and antidiabetic characteristics, underscoring their prospective uses in biomedical research.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430324/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040636","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":"One-Step Synthesis of Ultra-Small RhNPs in the Microreactor System and Their Deposition on ACF for Catalytic Conversion of 4-Nitrophenol to 4-Aminophenol.","authors":"Adrianna Pach, Konrad Wojtaszek, Ahmed Ibrahim Elhadad, Tomasz Michałek, Anna Kula, Magdalena Luty-Błocho","doi":"10.3390/nano15171375","DOIUrl":"10.3390/nano15171375","url":null,"abstract":"<p><p>The rising demand for platinum-group metals, driven by their essential applications in catalysis, energy storage, and chemical conversion, underscores the need to identify new sources for their recovery. Waste solutions originating from industrial processes offer a promising alternative source of noble metals. However, due to their typically low concentrations, effective recovery requires a highly targeted approach. In this study, we present a synthetic waste solution containing trace amount of Rh(III) ions as both a medium for metal ion recovery and a direct precursor for catalyst synthesis. Using a bimodal water-ethanol solvent system, ultra-small rhodium nanoparticles were synthesized and subsequently immobilized onto activated carbon fibers (ACFs) within a microreactor system. The resulting Rh@ACF catalyst demonstrated high efficiency in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), serving as a model catalytic reaction. The Rh@ACF catalyst, containing 4.24 µg Rh per milligram of sample, exhibited notable catalytic activity, achieving 75% conversion of 4-NP to 4-AP within 1 h. Full conversion to 4-AP was also reached within 5 min, but requires extra NaBH₄ addition to the catalytic mixture.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12429861/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040728","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":"Electrospun Polyimide Nanofibers Modified with Metal Oxide Nanowires and MXene for Photocatalytic Water Purification.","authors":"Andrii Lys, Valerii Myndrul, Mykola Pavlenko, Błażej Anastaziak, Pavel Holec, Kateřina Vodseďálková, Emerson Coy, Mikhael Bechelany, Igor Iatsunskyi","doi":"10.3390/nano15171371","DOIUrl":"10.3390/nano15171371","url":null,"abstract":"<p><p>As the demand for clean water continues to rise, the development of reliable and environmentally sustainable purification methods has become increasingly important. In this study, we describe the production and characterization of electrospun polyimide (PID) nanofibers modified with MXene (Ti₃C₂Tx), tungsten trioxide (WO₃), and titanium dioxide (TiO₂) nanomaterials for improved photocatalytic degradation of rhodamine 6G (R6G), a model organic dye. Superior photocatalytic performance was achieved by suppressing electron-hole recombination, promoting efficient charge carrier separation, and the significant increase in light absorption through the addition of metal oxide nanowires and MXene to the PID matrix. Comprehensive characterization confirms a core-shell nanofiber architecture with TiO₂, WO₃, and MXene effectively integrated and electronically coupled, consistent with the observed photocatalytic response. The PID/TiO₂/WO₃/MXene composite exhibited the highest photocatalytic activity among the tested configurations, degrading R6G by 74% in 90 min of light exposure. This enhancement was ascribed to the synergistic interactions between MXene and the metal oxides, which reduced recombination losses and promoted effective charge transfer. The study confirms the suitability of PID-based hybrid nanofibers for wastewater treatment applications. It also points toward future directions focused on scalable production and deployment in the field of environmental remediation.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430064/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040689","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":"Synthesis and Characterization of EG/Au Composites via Thermal Exfoliation of Graphite Intercalation Compounds with Tetrachloroauric Acid.","authors":"Aleksandr D Muravev, Andrei V Ivanov, Vladimir A Mukhanov, Boris A Kulnitskiy, Natalia V Maksimova, Victor V Avdeev","doi":"10.3390/nano15171363","DOIUrl":"10.3390/nano15171363","url":null,"abstract":"<p><p>This study demonstrates a novel route to synthesize gold-decorated exfoliated graphite (EG) through graphite intercalation compounds (GICs) with tetrachloroauric acid (HAuCl₄). We aimed to develop a scalable method for producing EG/Au composites with controlled nanoparticle morphology by investigating the effects of precursor chemistry and thermal expansion conditions. II-stage GIC-HAuCl₄ (average gross-composition: C₂₃HAuCl₄; intercalate layer thickness d_i = 6.85 Å) was prepared via an exchange reaction of HAuCl₄ with graphite nitrate. Interaction of this GIC with liquid methylamine yielded an occlusive complex, where methylamine-bound HAuCl₄ occupies both interlayer and intercrystalline spaces in the graphite matrix. Methylamine treatment of GIC reduces the onset temperature of exfoliation by ≈100 °C and enhances the expansion efficiency, yielding EG with a low bulk density range of 4-6 g/L when processed at 900 °C in air or nitrogen. Thermal exfoliation of these GICs yielded EG decorated with gold nanoparticles, exhibiting a broad size distribution from a few nanometers to several hundred nanometers, as confirmed by electron microscopy. An X-ray diffraction analysis identified the coexistence of crystalline gold and hexagonal graphite phases, with no detectable impurity phases.</p>","PeriodicalId":18966,"journal":{"name":"Nanomaterials","volume":"15 17","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12430493/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040911","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}