Pub Date : 2024-04-25DOI: 10.1088/2043-6262/ad3ddb
V. T. K. Oanh, L. H. Nguyen, L. Phong, M. T. T. Trang, H. P. Thu, N. X. Truong, N. X. Ca, P. H. Nam, D. H. Manh
Fe3O4/CoFe2O4 core/shell nanoparticles with varying shell thickness were fabricated by seed-mediated growth via thermal decomposition method. Ligand exchange process using poly(maleic anhydride-alt-1-octadecene) (PMAO) was performed to prepare the aqueous magnetic fluids from the as-synthesised nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Quantum Design PPMS VersaLab were utilised to characterise morphological and magnetic properties of the sample. XRD results showed that all the particles were single phase with spinel structure and the average crystallite size in the range of 11–17 nm. All particles were spherical in TEM images with similar size compared to results calculated from XRD. Magnetic measurements were performed at different temperatures (50 − 300 K) at 30 kOe. The result showed that the saturation magnetisation (M s) and coercivity (H C) were significantly increased with the formation of hard magnetic shell with varying thickness. The dynamic light scattering (DLS) analysis presented a narrow distribution and zeta potential of −16 to −35 mV, indicating a good stability of the ferrofluids. The cytotoxicity of the FOC3/PMAO ferrofluid, which has the highest SAR value of 372.02 W g−1, was tested on Hep-G2 cell line at different concentrations from 10 to 100 μg ml−1. Less than 30% of the cell was inhibited, indicating that the FOC3/PMAO particles have low toxicity at these tested concentrations. Thus, these as-synthesised core/shell nanoparticles with uniform particle size, high saturation magnetisation, good stability and five-time increased specific absorption rate (SAR) compared to the Fe3O4 core nanoparticles are very promising in hyperthermia and magnetic resonance imaging (MRI) applications.
{"title":"Fe3O4/CoFe2O4 core-shell nanoparticles with enhanced magnetic properties for hyperthermia application","authors":"V. T. K. Oanh, L. H. Nguyen, L. Phong, M. T. T. Trang, H. P. Thu, N. X. Truong, N. X. Ca, P. H. Nam, D. H. Manh","doi":"10.1088/2043-6262/ad3ddb","DOIUrl":"https://doi.org/10.1088/2043-6262/ad3ddb","url":null,"abstract":"\u0000 Fe3O4/CoFe2O4 core/shell nanoparticles with varying shell thickness were fabricated by seed-mediated growth via thermal decomposition method. Ligand exchange process using poly(maleic anhydride-alt-1-octadecene) (PMAO) was performed to prepare the aqueous magnetic fluids from the as-synthesised nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Quantum Design PPMS VersaLab were utilised to characterise morphological and magnetic properties of the sample. XRD results showed that all the particles were single phase with spinel structure and the average crystallite size in the range of 11–17 nm. All particles were spherical in TEM images with similar size compared to results calculated from XRD. Magnetic measurements were performed at different temperatures (50 − 300 K) at 30 kOe. The result showed that the saturation magnetisation (M\u0000 s) and coercivity (H\u0000 C) were significantly increased with the formation of hard magnetic shell with varying thickness. The dynamic light scattering (DLS) analysis presented a narrow distribution and zeta potential of −16 to −35 mV, indicating a good stability of the ferrofluids. The cytotoxicity of the FOC3/PMAO ferrofluid, which has the highest SAR value of 372.02 W g−1, was tested on Hep-G2 cell line at different concentrations from 10 to 100 μg ml−1. Less than 30% of the cell was inhibited, indicating that the FOC3/PMAO particles have low toxicity at these tested concentrations. Thus, these as-synthesised core/shell nanoparticles with uniform particle size, high saturation magnetisation, good stability and five-time increased specific absorption rate (SAR) compared to the Fe3O4 core nanoparticles are very promising in hyperthermia and magnetic resonance imaging (MRI) applications.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"40 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140656994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Green synthesis of silver nanoparticles (AgNPs) using fruit peel extract has gained considerable interest, as it is an eco-friendly and cost-effective method. However, studies on the use of biosynthesised AgNPs to sterilise plant tissue culture medium as an alternative to autoclaving are limited. Thus, this study presented a biogenic method for synthesising AgNPs using mangosteen peel extract. The biosynthesised AgNPs were characterised by different spectroscopic and microscopic methods, including UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive x-ray spectroscopy. The results showed that the phytochemical constituents in the mangosteen peel extract (MPE) helped to reduce Ag+ from AgNO3 to metallic silver (Ag0) and stabilise the particles. The formation of biogenic AgNPs was monitored by UV-vis demonstrating a characteristic peak at 425 nm. The AgNPs were spherical and crystalline. The size distribution of the biogenic AgNPs was 5–47 nm with an average diameter of 23.1 ± 6.8 nm. To evaluate the potential of the AgNPs for use as an alternative method to sterilise the culture medium, the antimicrobial activity of the biosynthesised AgNPs (0.1, 1, 10, 100, and 1000 mg l−1) was tested in the banana culture medium. The most feasible concentration of AgNPs to decontaminate the culture medium was 100 mg l−1. Moreover, the results demonstrated that adding 100 mg l−1 AgNPs to the culture medium promoted the growth of the plantlets without any toxic effects. Thus, biogenic AgNPs are a potential biocide to sterilise in vitro banana culture medium.
{"title":"Effect of biosynthesised silver nanoparticles as sterilant on physiological and biochemical characteristics in micropropagation of Musa sapientum L.","authors":"Siriporn Phongtongpasuk, Thitikamon Liamnimit, Thanyaporn Buakaew, Manthita Homsuwan, Suppanuch Khamphong, N. Yongvanich","doi":"10.1088/2043-6262/ad3b7d","DOIUrl":"https://doi.org/10.1088/2043-6262/ad3b7d","url":null,"abstract":"\u0000 Green synthesis of silver nanoparticles (AgNPs) using fruit peel extract has gained considerable interest, as it is an eco-friendly and cost-effective method. However, studies on the use of biosynthesised AgNPs to sterilise plant tissue culture medium as an alternative to autoclaving are limited. Thus, this study presented a biogenic method for synthesising AgNPs using mangosteen peel extract. The biosynthesised AgNPs were characterised by different spectroscopic and microscopic methods, including UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive x-ray spectroscopy. The results showed that the phytochemical constituents in the mangosteen peel extract (MPE) helped to reduce Ag+ from AgNO3 to metallic silver (Ag0) and stabilise the particles. The formation of biogenic AgNPs was monitored by UV-vis demonstrating a characteristic peak at 425 nm. The AgNPs were spherical and crystalline. The size distribution of the biogenic AgNPs was 5–47 nm with an average diameter of 23.1 ± 6.8 nm. To evaluate the potential of the AgNPs for use as an alternative method to sterilise the culture medium, the antimicrobial activity of the biosynthesised AgNPs (0.1, 1, 10, 100, and 1000 mg l−1) was tested in the banana culture medium. The most feasible concentration of AgNPs to decontaminate the culture medium was 100 mg l−1. Moreover, the results demonstrated that adding 100 mg l−1 AgNPs to the culture medium promoted the growth of the plantlets without any toxic effects. Thus, biogenic AgNPs are a potential biocide to sterilise in vitro banana culture medium.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"50 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140662877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-24DOI: 10.1088/2043-6262/ad3de0
Mary Elyssa R Rañoa, Matthew L. Villanueva, J. R. Laxamana, H. G. G. Necesito, B. J. Tongol
This study utilised coconut husk biochar as an alternative sustainable carbon support for Pd-based electrocatalyst for ethanol oxidation reaction in basic medium. Coconut husk biochar (BC) was prepared via slow pyrolysis at 800 °C for 1 h at a ramp rate of 5 °C min−1. The Pd/BC catalyst was prepared via borohydride-facilitated reduction of palladium chloride solution. TEM analysis revealed good dispersion of the Pd nanoparticles on the biochar support with particle size ranging from 1.9 to 3.4 nm. Cyclic voltammetry (CV) measurements of Pd/BC in 1.0 M ethanol in 0.1 M KOH gave an on-set potential of −0.615 V (versus Ag/AgCl) with a forward peak current density of 23.87 mA cm−2, which is slightly higher than the commercial Pd/C catalyst. The Pd/BC also has a higher electrochemical stability and durability than the commercial Pd/C catalyst based on chronoamperometry studies (i.e., 44.43% versus 39.64% current retention). The synthesised coconut husk biochar–supported Pd catalyst exhibited promising results for ethanol oxidation reaction for alkaline direct ethanol fuel cell application.
本研究利用椰壳生物炭作为钯基电催化剂在碱性介质中进行乙醇氧化反应的替代性可持续碳载体。椰壳生物炭（BC）的制备方法是在 800 °C 下以 5 °C min-1 的升温速率缓慢热解 1 小时。Pd/BC 催化剂是通过硼氢化促进氯化钯溶液还原制备的。TEM 分析表明，钯纳米颗粒在生物炭载体上分散良好，粒径范围为 1.9 至 3.4 nm。在 1.0 M 乙醇和 0.1 M KOH 溶液中对 Pd/BC 进行的循环伏安（CV）测量显示，其导通电位为 -0.615 V（相对于 Ag/AgCl），正向峰值电流密度为 23.87 mA cm-2，略高于商用 Pd/C 催化剂。根据时变研究，Pd/BC 的电化学稳定性和耐用性也高于商用 Pd/C 催化剂（即电流保持率为 44.43% 对 39.64%）。合成的椰糠生物炭支撑钯催化剂在碱性直接乙醇燃料电池应用的乙醇氧化反应中表现出良好的效果。
{"title":"Palladium/coconut husk biochar composite material as an effective electrocatalyst for ethanol oxidation reaction","authors":"Mary Elyssa R Rañoa, Matthew L. Villanueva, J. R. Laxamana, H. G. G. Necesito, B. J. Tongol","doi":"10.1088/2043-6262/ad3de0","DOIUrl":"https://doi.org/10.1088/2043-6262/ad3de0","url":null,"abstract":"\u0000 This study utilised coconut husk biochar as an alternative sustainable carbon support for Pd-based electrocatalyst for ethanol oxidation reaction in basic medium. Coconut husk biochar (BC) was prepared via slow pyrolysis at 800 °C for 1 h at a ramp rate of 5 °C min−1. The Pd/BC catalyst was prepared via borohydride-facilitated reduction of palladium chloride solution. TEM analysis revealed good dispersion of the Pd nanoparticles on the biochar support with particle size ranging from 1.9 to 3.4 nm. Cyclic voltammetry (CV) measurements of Pd/BC in 1.0 M ethanol in 0.1 M KOH gave an on-set potential of −0.615 V (versus Ag/AgCl) with a forward peak current density of 23.87 mA cm−2, which is slightly higher than the commercial Pd/C catalyst. The Pd/BC also has a higher electrochemical stability and durability than the commercial Pd/C catalyst based on chronoamperometry studies (i.e., 44.43% versus 39.64% current retention). The synthesised coconut husk biochar–supported Pd catalyst exhibited promising results for ethanol oxidation reaction for alkaline direct ethanol fuel cell application.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"50 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140660818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-23DOI: 10.1088/2043-6262/ad3ddf
Pujashree Priyadarshini Sethy, B. Sundaray
We describe a simple co-axial electrospinning approach followed by a carbonisation process to create cobalt-carbon (Co-C) nanofibers that are then thoroughly analysed using various techniques. X-ray diffraction measurements showed the creation of pure crystalline cobalt with face-centered cubic (fcc) structure, and average crystallite size was determined using the Debye–Scherrer formula. The average crystallite size has been calculated to be in the range of 10 − 15 nm. According to the Raman investigation, all Co-C nanofibers have an amorphous carbon structure with little graphitic behaviour. Field emission scanning electron microscopy was used to determine the shape and average diameter of electrospun nanofibers. The field-dependent magnetic characterisation demonstrated a satisfactory ferromagnetic behaviour with maximum saturation magnetisation values of 10, 10.2, and 11.2 emu/g for Co12.5-C sample at 300, 100, and 5 K, respectively. Compared to bulk cobalt, the produced Co-C nanofibers have a high coercivity value. With average crystallite size, the coercivity varies. Again, magnetisation versus temperature measurements have supported the existence of ferromagnetism because there is no evidence of blocking temperature or any transitional behaviour below 300 K. As a result, applications for microwave absorption, catalysis, and several magnetic recording devices can benefit from the coupling of ferromagnetic properties with carbon nanofiber materials.
{"title":"Facile synthesis of co-axially electrospun Co-C nanofibers and their ferromagnetic behavior","authors":"Pujashree Priyadarshini Sethy, B. Sundaray","doi":"10.1088/2043-6262/ad3ddf","DOIUrl":"https://doi.org/10.1088/2043-6262/ad3ddf","url":null,"abstract":"\u0000 We describe a simple co-axial electrospinning approach followed by a carbonisation process to create cobalt-carbon (Co-C) nanofibers that are then thoroughly analysed using various techniques. X-ray diffraction measurements showed the creation of pure crystalline cobalt with face-centered cubic (fcc) structure, and average crystallite size was determined using the Debye–Scherrer formula. The average crystallite size has been calculated to be in the range of 10 − 15 nm. According to the Raman investigation, all Co-C nanofibers have an amorphous carbon structure with little graphitic behaviour. Field emission scanning electron microscopy was used to determine the shape and average diameter of electrospun nanofibers. The field-dependent magnetic characterisation demonstrated a satisfactory ferromagnetic behaviour with maximum saturation magnetisation values of 10, 10.2, and 11.2 emu/g for Co12.5-C sample at 300, 100, and 5 K, respectively. Compared to bulk cobalt, the produced Co-C nanofibers have a high coercivity value. With average crystallite size, the coercivity varies. Again, magnetisation versus temperature measurements have supported the existence of ferromagnetism because there is no evidence of blocking temperature or any transitional behaviour below 300 K. As a result, applications for microwave absorption, catalysis, and several magnetic recording devices can benefit from the coupling of ferromagnetic properties with carbon nanofiber materials.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"75 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140670635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1088/2043-6262/ad3b7a
Karthick Harini, K. Girigoswami, P. Pallavi, Pemula Gowtham, Alex Daniel Prabhu, A. Girigoswami
Magnetic particle imaging (MPI) has gained significant traction as an ionising radiation-free tomographic method that offers real-time imaging capabilities with enhanced sensitivity and resolutions. In this technique, magnetic nanoparticles (MNPs) are employed, particularly iron oxide nanoparticles with superparamagnetic nature, as probes within the MPI system. These MNPs enable the tracking and precise quantification of particle movement with minimal background noise. The 3D location and concentration of MNPs can provide better insights for multiple applications in vascular imaging, cell tracking, cancer cell imaging, inflammation, implant monitoring, and trauma imaging and can thus accelerate the diagnosis of disorders. The mononuclear phagocyte system provides a significant advantage, as they are involved in the spontaneous clearance of the tracers used in MPI, which readily minimise the toxic effects. Several studies have demonstrated that MPI-based functional neuroimaging is superior to other imaging modalities, providing adequate temporal resolution images with quick scan intervals. In MPI, nanoparticles are solely responsible for the source and visualisation, unlike magnetic resonance imaging (MRI), where nanoparticles were used only as supportive tracers. This review provides an overview of the principle, diagnostic, and therapeutic applications of MPI as well as the advantages and challenges MPI has over other diagnostic imaging methods in modern clinical setups.
{"title":"Advancement of magnetic particle imaging in diagnosis and therapy","authors":"Karthick Harini, K. Girigoswami, P. Pallavi, Pemula Gowtham, Alex Daniel Prabhu, A. Girigoswami","doi":"10.1088/2043-6262/ad3b7a","DOIUrl":"https://doi.org/10.1088/2043-6262/ad3b7a","url":null,"abstract":"\u0000 Magnetic particle imaging (MPI) has gained significant traction as an ionising radiation-free tomographic method that offers real-time imaging capabilities with enhanced sensitivity and resolutions. In this technique, magnetic nanoparticles (MNPs) are employed, particularly iron oxide nanoparticles with superparamagnetic nature, as probes within the MPI system. These MNPs enable the tracking and precise quantification of particle movement with minimal background noise. The 3D location and concentration of MNPs can provide better insights for multiple applications in vascular imaging, cell tracking, cancer cell imaging, inflammation, implant monitoring, and trauma imaging and can thus accelerate the diagnosis of disorders. The mononuclear phagocyte system provides a significant advantage, as they are involved in the spontaneous clearance of the tracers used in MPI, which readily minimise the toxic effects. Several studies have demonstrated that MPI-based functional neuroimaging is superior to other imaging modalities, providing adequate temporal resolution images with quick scan intervals. In MPI, nanoparticles are solely responsible for the source and visualisation, unlike magnetic resonance imaging (MRI), where nanoparticles were used only as supportive tracers. This review provides an overview of the principle, diagnostic, and therapeutic applications of MPI as well as the advantages and challenges MPI has over other diagnostic imaging methods in modern clinical setups.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"23 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140674732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1088/2043-6262/ad3b7c
Ghazal Ghaznavi, Samaneh Hashemi, Mohammad Mahdi Abolhosseini, Parisa Vosough, Parvin Lohrasbi, Saeed Taghizadeh, Amir Savardashtaki
The human gastrointestinal tract is colonised by a multifaceted and dynamic population of microorganisms consisting of trillions of microbes called the gut microbiota. Through extensive research using animal models and human studies, the significant contributions of gut microbiota to immune and metabolic balance, protection against pathogens, and even neurobehavioural traits have been established. Members of the genus Bifidobacterium are the first bacteria to colonise the intestinal tract in infants, and now it has been proven that they play a positive role in enhancing the host immunity, nutrient absorption, reducing and treating gastrointestinal infections, as well as improving conditions such as diarrhea, constipation, and eczema. Bacterial nanotechnology is a rapidly growing research area with great potential for improvement and the discovery of innovations in new applications of bacteria such as Bifidobacterium. In this review, we provide an up-to-date summary of the relations of nanotechnology with Bifidobacterium in various fields, including bacterial synthesis of nanoparticles, encapsulation of bacteria, bacterial toxicity of nanomaterial, application in the field of cancer targeting, and also the treatment of other diseases such as Alzheimer’s and IBD.
{"title":"New insights into the role of nanotechnology in Bifidobacterium biomedical applications","authors":"Ghazal Ghaznavi, Samaneh Hashemi, Mohammad Mahdi Abolhosseini, Parisa Vosough, Parvin Lohrasbi, Saeed Taghizadeh, Amir Savardashtaki","doi":"10.1088/2043-6262/ad3b7c","DOIUrl":"https://doi.org/10.1088/2043-6262/ad3b7c","url":null,"abstract":"\u0000 The human gastrointestinal tract is colonised by a multifaceted and dynamic population of microorganisms consisting of trillions of microbes called the gut microbiota. Through extensive research using animal models and human studies, the significant contributions of gut microbiota to immune and metabolic balance, protection against pathogens, and even neurobehavioural traits have been established. Members of the genus Bifidobacterium are the first bacteria to colonise the intestinal tract in infants, and now it has been proven that they play a positive role in enhancing the host immunity, nutrient absorption, reducing and treating gastrointestinal infections, as well as improving conditions such as diarrhea, constipation, and eczema. Bacterial nanotechnology is a rapidly growing research area with great potential for improvement and the discovery of innovations in new applications of bacteria such as Bifidobacterium. In this review, we provide an up-to-date summary of the relations of nanotechnology with Bifidobacterium in various fields, including bacterial synthesis of nanoparticles, encapsulation of bacteria, bacterial toxicity of nanomaterial, application in the field of cancer targeting, and also the treatment of other diseases such as Alzheimer’s and IBD.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"36 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140672977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-22DOI: 10.1088/2043-6262/ad3ddc
Bui Gia Man Nguyen, Ha Ngoc Duy Huynh, Nhat Minh Nguyen, Phan Phuong Ha La, Le Thai Duy, V. Dang
Polyimide (PI), which have many remarkable features such as excellent mechanical strength, outstanding thermal stability, exceptional electric properties, etc, is a potential carrier for optoelectronic devices due to its abundant applications. However, because of chemical inertness and smooth surface that led to the growth of materials on this substrate being more complex than that on rigid substrate, thus, this report aims to emphasise the synthesis of ZnO NRs decorated with the Ag NPs on flexible substrate for photodetector application. In this study, we successfully synthesise ZnO NRs/Ag NPs on a flexible PI substrate by the hydrothermal method. The performance of our photodetector in visible region (395 nm) exhibits via the responsivity of the device, which recorded value of ca. 40.16 mA W−1 at 1.66 mW cm−2. With obtained results, our research can pave the way for future studies based on flexible optoelectronic devices.
聚酰亚胺（PI）具有卓越的机械强度、出色的热稳定性和优异的电性能等诸多显著特征，因其应用广泛而成为光电器件的潜在载体。然而，由于化学惰性和光滑的表面导致材料在这种基底上的生长比在刚性基底上的生长更为复杂，因此，本报告旨在强调在柔性基底上合成饰有 Ag NPs 的 ZnO NRs，以应用于光电探测器。在本研究中，我们采用水热法在柔性 PI 基底上成功合成了 ZnO NRs/Ag NPs。我们的光电探测器在可见光区域（395 nm）的性能通过该器件的响应度得以体现，在 1.66 mW cm-2 的条件下，该器件的响应度值约为 40.16 mA W-1。有了这些成果，我们的研究可以为未来基于柔性光电器件的研究铺平道路。
{"title":"Synthesis of ZnO nanorods decorating with Ag nanoparticles on flexible polyimide substrate for visible photodetector application","authors":"Bui Gia Man Nguyen, Ha Ngoc Duy Huynh, Nhat Minh Nguyen, Phan Phuong Ha La, Le Thai Duy, V. Dang","doi":"10.1088/2043-6262/ad3ddc","DOIUrl":"https://doi.org/10.1088/2043-6262/ad3ddc","url":null,"abstract":"\u0000 Polyimide (PI), which have many remarkable features such as excellent mechanical strength, outstanding thermal stability, exceptional electric properties, etc, is a potential carrier for optoelectronic devices due to its abundant applications. However, because of chemical inertness and smooth surface that led to the growth of materials on this substrate being more complex than that on rigid substrate, thus, this report aims to emphasise the synthesis of ZnO NRs decorated with the Ag NPs on flexible substrate for photodetector application. In this study, we successfully synthesise ZnO NRs/Ag NPs on a flexible PI substrate by the hydrothermal method. The performance of our photodetector in visible region (395 nm) exhibits via the responsivity of the device, which recorded value of ca. 40.16 mA W−1 at 1.66 mW cm−2. With obtained results, our research can pave the way for future studies based on flexible optoelectronic devices.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140677285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1088/2043-6262/ad2c7d
T. Huynh, Quyen Huynh, Ngoc-Han T Huynh, Hau Quoc Pham
In this work, we prepared an Ir,N-doped TiO2 nanomaterial via a facile HNO3-assisted hydrothermal process that was used as an advanced support for nano-sized Pt nanoparticles (NPs) for the formic acid oxidation reaction (FAOR). The physical and electrochemical behaviours of the as-made Pt/Ir,N-doped TiO2 catalyst were systemically investigated through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopes coupled with energy dispersive X-ray analysis (FE-SEM/EDX mapping), transmission electron microscopy (TEM), linear sweep voltammetry (LSV), Tafel slope, CO-stripping, and chronoamperometric (CA) test. The Pt NPs (ca. 3 nm) were anchored on the Ir,N-doped TiO2 support, being formed by a mixture of rutile and brookite with a particle size of several ten nanometers. Due to the small size and uniform distribution of Pt NPs, the Pt/Ir,N-doped TiO2 catalyst had an electrochemical surface area of 79.88 m2 g−1, which was greater than that of the commercial Pt/C (77.63 m2 g−1). In terms of the FAOR, the Pt/Ir,N-doped TiO2 catalyst showed a negative FAOR onset potential, high current density (11.85 mA cm−2), and superior CO-tolerance compared to the commercially available catalyst. Also, the as-made catalyst possessed high electrochemical durability after 3600 s for testing. The enhanced FAOR efficiency was assigned to the formation of a dual-doping effect and strong interplay between Pt and TiO2-based support, which not only improved the electron transfer but also weakened the adsorption of carbonaceous species, thereby boosting the reaction kinetics. This study could open up a facile but effective strategy to promote particular electrochemical applications.
{"title":"Enhanced formic acid electro-oxidation reaction over Ir,N-doped TiO2-supported Pt nanocatalyst","authors":"T. Huynh, Quyen Huynh, Ngoc-Han T Huynh, Hau Quoc Pham","doi":"10.1088/2043-6262/ad2c7d","DOIUrl":"https://doi.org/10.1088/2043-6262/ad2c7d","url":null,"abstract":"\u0000 In this work, we prepared an Ir,N-doped TiO2 nanomaterial via a facile HNO3-assisted hydrothermal process that was used as an advanced support for nano-sized Pt nanoparticles (NPs) for the formic acid oxidation reaction (FAOR). The physical and electrochemical behaviours of the as-made Pt/Ir,N-doped TiO2 catalyst were systemically investigated through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopes coupled with energy dispersive X-ray analysis (FE-SEM/EDX mapping), transmission electron microscopy (TEM), linear sweep voltammetry (LSV), Tafel slope, CO-stripping, and chronoamperometric (CA) test. The Pt NPs (ca. 3 nm) were anchored on the Ir,N-doped TiO2 support, being formed by a mixture of rutile and brookite with a particle size of several ten nanometers. Due to the small size and uniform distribution of Pt NPs, the Pt/Ir,N-doped TiO2 catalyst had an electrochemical surface area of 79.88 m2 g−1, which was greater than that of the commercial Pt/C (77.63 m2 g−1). In terms of the FAOR, the Pt/Ir,N-doped TiO2 catalyst showed a negative FAOR onset potential, high current density (11.85 mA cm−2), and superior CO-tolerance compared to the commercially available catalyst. Also, the as-made catalyst possessed high electrochemical durability after 3600 s for testing. The enhanced FAOR efficiency was assigned to the formation of a dual-doping effect and strong interplay between Pt and TiO2-based support, which not only improved the electron transfer but also weakened the adsorption of carbonaceous species, thereby boosting the reaction kinetics. This study could open up a facile but effective strategy to promote particular electrochemical applications.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"22 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140083683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1088/2043-6262/ad2fb6
Phuong T M Nguyen, Tai Nguyen, Thu-Hien Vu
Obtaining high purity alkali niobate (K x Na1-x NbO3) thin films without secondary phase on metal coated traditional silicon (Si) substrates via sol–gel technique has remained great challenges until now. Herein, we report K0.5Na0.5NbO3 (KNN) thin films successfully deposited on Pt/Ti/SiO2/Si(100) substrates by a simply effective sol–gel process. A comprehensive and systematic investigation of processing conditions on the microstructures and electrical properties of spin-coated KNN films was presented. We have found that phase purity and microstructures of KNN films are strongly influenced by content of alkali excess and the annealing temperature. Thin films with an equal excess amount of 10% mol K and Na (KNN1) sintered at 650 °C show high crystallinity with a preferred (100)-orientation degree of 78%, and homogeneous and dense surface with columnar structure and large grain size up to 254 nm. The result of quantitative XPS analysis has proved that the composition of the film is close to the chemical stoichiometry. As a consequence, the obtained KNN1 films exhibit a large dielectric constant of 775 and low dielectric loss of ∼2% in the wide frequency range from 1kHz up to 10MHz as well as the best shape of P−E loops. Furthermore, leakage current density of the film is about 9.45 × 10−5 A cm−2 at E ≈100 kV cm−1.
迄今为止，通过溶胶-凝胶技术在金属镀层传统硅（Si）基底上获得无次相的高纯度碱铌酸盐（K x Na1-x NbO3）薄膜仍是一项巨大挑战。在此，我们报告了通过简单有效的溶胶-凝胶工艺在 Pt/Ti/SiO2/Si(100) 基底上成功沉积 K0.5Na0.5NbO3 (KNN) 薄膜的情况。我们全面系统地研究了加工条件对旋涂 KNN 薄膜微观结构和电学特性的影响。我们发现，KNN 薄膜的相纯度和微观结构受碱过量含量和退火温度的影响很大。在 650 °C 下烧结的等量过剩 10% mol K 和 Na 的薄膜（KNN1）显示出较高的结晶度，首选 (100) 取向度为 78%，表面均匀致密，具有柱状结构，晶粒大小可达 254 nm。XPS 定量分析结果证明，薄膜的成分接近化学计量。因此，获得的 KNN1 薄膜在 1kHz 至 10MHz 的宽频率范围内具有 775 的大介电常数和 ∼2% 的低介电损耗，以及最佳的 P-E 环形状。此外，在 E ≈100 kV cm-1 时，薄膜的漏电流密度约为 9.45 × 10-5 A cm-2。
{"title":"Facile preparation of KNN thin film with high purity phase and excellent electrical properties","authors":"Phuong T M Nguyen, Tai Nguyen, Thu-Hien Vu","doi":"10.1088/2043-6262/ad2fb6","DOIUrl":"https://doi.org/10.1088/2043-6262/ad2fb6","url":null,"abstract":"\u0000 Obtaining high purity alkali niobate (K\u0000 x\u0000 Na1-x\u0000 NbO3) thin films without secondary phase on metal coated traditional silicon (Si) substrates via sol–gel technique has remained great challenges until now. Herein, we report K0.5Na0.5NbO3 (KNN) thin films successfully deposited on Pt/Ti/SiO2/Si(100) substrates by a simply effective sol–gel process. A comprehensive and systematic investigation of processing conditions on the microstructures and electrical properties of spin-coated KNN films was presented. We have found that phase purity and microstructures of KNN films are strongly influenced by content of alkali excess and the annealing temperature. Thin films with an equal excess amount of 10% mol K and Na (KNN1) sintered at 650 °C show high crystallinity with a preferred (100)-orientation degree of 78%, and homogeneous and dense surface with columnar structure and large grain size up to 254 nm. The result of quantitative XPS analysis has proved that the composition of the film is close to the chemical stoichiometry. As a consequence, the obtained KNN1 films exhibit a large dielectric constant of 775 and low dielectric loss of ∼2% in the wide frequency range from 1kHz up to 10MHz as well as the best shape of P−E loops. Furthermore, leakage current density of the film is about 9.45 × 10−5 A cm−2 at E ≈100 kV cm−1.","PeriodicalId":56371,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"46 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140279894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1088/2043-6262/ad2dc7
Nurul Farhana Abu Kasim, N. A. Halim, K. K. Ong, S. Demon
One pot synthesis of graphene nanocomposites is low-cost and time-efficient methodology to be considered for large scale device fabrication. Graphene precursors made of renewable and waste materials such as rice husk, oil palm kernel and sugar are explored upon rising concern of expensiveness and hazard in conventional approaches. This paper presents chemical characterisation study of one pot reduced graphene oxide/gold nanoparticles (RGO/AuNPs) synthesised from low-cost sucrose as precursor and dehydroascorbic acid as green reducing agent at ambient condition which was originally used by Hurtado et al in 2020. Raman spectrum of RGO/AuNPs was compared to composite of commercial GO precursor to evaluate quality of reduction products. Result from UV–vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) showed that both techniques successfully eliminated oxygen-containing functional groups to form graphene constitution. Asides from lower stability, AuNPs in sucrose-derived RGO possessed larger size and was more dispersed than those of GO-derived RGO, implying the need to optimise the current recipe. Reduction mechanism of both precursors was proposed for better understanding. The aim of this work is to show feasibility of green graphene nanocomposite synthesis that could empower productivity of electronic, optical and optoelectronics applications.
一次性合成石墨烯纳米复合材料是一种低成本、高效率的方法，可用于大规模设备制造。由于人们越来越关注传统方法的昂贵性和危险性，由稻壳、油棕仁和糖等可再生废旧材料制成的石墨烯前驱体得到了探索。本文介绍了以低成本蔗糖为前驱体、脱氢抗坏血酸为绿色还原剂在环境条件下合成的一锅还原氧化石墨烯/金纳米粒子（RGO/AuNPs）的化学特性研究。将 RGO/AuNPs 的拉曼光谱与商用 GO 前体的复合拉曼光谱进行比较，以评估还原产物的质量。紫外-可见光谱、傅立叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）的结果表明，这两种技术都成功地消除了含氧官能团，形成了石墨烯结构。除了稳定性较低之外，蔗糖衍生的 RGO 中的 AuNPs 比 GO 衍生的 RGO 中的 AuNPs 尺寸更大、更分散，这意味着需要优化当前的配方。为了更好地理解这两种前驱体的还原机制，我们提出了一些建议。这项工作旨在展示绿色石墨烯纳米复合材料合成的可行性，从而提高电子、光学和光电应用的生产率。
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