Pub Date : 2023-11-30DOI: 10.1088/2043-6262/ad089f
Bui Thi Hang, Tran Van Dang, Nguyen Van Quy
In this study, Fe(NO3)3.6H2O was used as the iron source for synthesising Fe2O3 and Fe2O3/C nanomaterials by microwave together with calcination. Physical characterisations of the synthesised materials have been evaluated by x-ray diffraction (XRD) and scanning electron microscopy (SEM) together with x-ray energy-dispersive spectroscopy (EDS), respectively. The Fe2O3/C composite electrodes were prepared based on Fe2O3/C nanomaterials and used as the negative electrode in the iron-based rechargeable battery. The electrochemical properties of Fe2O3/C composite electrodes were investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. The obtained results show that the synthesised conditions affect the redox reactions of the Fe2O3/C electrodes. The influences of additives on the electrochemical properties of Fe2O3/C electrodes were also examined. The additives in electrode and electrolyte improved the cyclability, discharge capacity of Fe2O3/C electrode.
{"title":"Fe2O3/C nanomaterials synthesized by microwave for energy storage applications","authors":"Bui Thi Hang, Tran Van Dang, Nguyen Van Quy","doi":"10.1088/2043-6262/ad089f","DOIUrl":"https://doi.org/10.1088/2043-6262/ad089f","url":null,"abstract":"In this study, Fe(NO<sub>3</sub>)<sub>3</sub>.6H<sub>2</sub>O was used as the iron source for synthesising Fe<sub>2</sub>O<sub>3</sub> and Fe<sub>2</sub>O<sub>3</sub>/C nanomaterials by microwave together with calcination. Physical characterisations of the synthesised materials have been evaluated by x-ray diffraction (XRD) and scanning electron microscopy (SEM) together with x-ray energy-dispersive spectroscopy (EDS), respectively. The Fe<sub>2</sub>O<sub>3</sub>/C composite electrodes were prepared based on Fe<sub>2</sub>O<sub>3</sub>/C nanomaterials and used as the negative electrode in the iron-based rechargeable battery. The electrochemical properties of Fe<sub>2</sub>O<sub>3</sub>/C composite electrodes were investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. The obtained results show that the synthesised conditions affect the redox reactions of the Fe<sub>2</sub>O<sub>3</sub>/C electrodes. The influences of additives on the electrochemical properties of Fe<sub>2</sub>O<sub>3</sub>/C electrodes were also examined. The additives in electrode and electrolyte improved the cyclability, discharge capacity of Fe<sub>2</sub>O<sub>3</sub>/C electrode.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"28 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692132","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 : 2023-11-22DOI: 10.1088/2043-6262/ad095c
Marek P Kobylański, Agnieszka Tercjak, Hynd Remita, Xiaojiao Yuan, Onur Cavdar, Junkal Gutierrez, Adriana Zaleska-Medynska
This study describes the synthesis and characterisation of a hybrid material consisting of titanium dioxide nanotube arrays (TiO2 NTs) modified by platinum nanoparticles (Pt-TiO2 NTs) via radiolysis and a conductive poly(3,4-ethylenedioxythiophene) (PEDOT) layer, for the first time. The NTs were fabricated by a two-step anodic oxidation process and exhibited different morphologies using electrolyte solutions with different water contents (2–10 vol%). The polymer layer of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) was coated on the Pt-TiO2 scaffold using the casting method. The PEDOT:PSS-PT-TiO2 NTs exhibited stability in the photocatalytic process after additional calcination which was carried out to remove the PSS part; the nanotubes with lengths of ∼3 μm exhibited the highest photocatalytic activity (∼4.5 × 10−3μmol cm−2 of H2). Additionally, the samples obtained from electrolyte solutions containing 5 and 10 vol% water exhibited nanostructures with the highest catalytic activity.
{"title":"A PEDOT-Pt-TiO2 hybrid material synthesized by the casting method for photocatalytic hydrogen generation","authors":"Marek P Kobylański, Agnieszka Tercjak, Hynd Remita, Xiaojiao Yuan, Onur Cavdar, Junkal Gutierrez, Adriana Zaleska-Medynska","doi":"10.1088/2043-6262/ad095c","DOIUrl":"https://doi.org/10.1088/2043-6262/ad095c","url":null,"abstract":"This study describes the synthesis and characterisation of a hybrid material consisting of titanium dioxide nanotube arrays (TiO<sub>2</sub> NTs) modified by platinum nanoparticles (Pt-TiO<sub>2</sub> NTs) via radiolysis and a conductive poly(3,4-ethylenedioxythiophene) (PEDOT) layer, for the first time. The NTs were fabricated by a two-step anodic oxidation process and exhibited different morphologies using electrolyte solutions with different water contents (2–10 vol%). The polymer layer of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) was coated on the Pt-TiO<sub>2</sub> scaffold using the casting method. The PEDOT:PSS-PT-TiO<sub>2</sub> NTs exhibited stability in the photocatalytic process after additional calcination which was carried out to remove the PSS part; the nanotubes with lengths of ∼3 <italic toggle=\"yes\">μ</italic>m exhibited the highest photocatalytic activity (∼4.5 × 10<sup>−3</sup>\u0000<italic toggle=\"yes\">μ</italic>mol cm<sup>−2</sup> of H<sub>2</sub>). Additionally, the samples obtained from electrolyte solutions containing 5 and 10 vol% water exhibited nanostructures with the highest catalytic activity.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"1 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692726","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 : 2023-11-16DOI: 10.1088/2043-6262/ad09c5
A Juliet Christina Mary, M Santhanalakshmi, L Lavanya
Nickel pyrophosphate nanostructures have been synthesized by a simple co-precipitation method. Annealing temperature affected the crystal structure formation of α-Ni2P2O7 and altered the surface morphology. By increasing the annealing temperature from 350 °C to 900 °C, the morphology of the material varies from irregularly shaped agglomerated particles to dumbbell-shaped nanoparticles respectively. The electrochemical performance of α-Ni2P2O7 nanoflakes (NP-2) and dumbbell-shaped (NP-3) nanoparticles is tested at 1 M KOH electrolyte solution, which provides the maximum specific capacitance of 146 and 121 F g−1 at a current density of 0.8 A g−1 respectively. Furthermore, the antibacterial activity of NP-2 nanoflakes is tested against different pathogenic Gram-positive and Gram-negative bacteria. The highest value of the inhibition zone exhibits the good antibiotic nature of the α-Ni2P2O7 nanoflakes.
通过简单的共沉淀法合成了焦磷酸镍纳米结构。退火温度影响了 α-Ni2P2O7 晶体结构的形成，并改变了其表面形态。将退火温度从 350 °C 提高到 900 °C，材料的形态分别从不规则的团聚颗粒变为哑铃状的纳米颗粒。在 1 M KOH 电解质溶液中测试了 α-Ni2P2O7 纳米片（NP-2）和哑铃形（NP-3）纳米粒子的电化学性能，在电流密度为 0.8 A g-1 时，它们的最大比电容分别为 146 F g-1 和 121 F g-1。此外，还测试了 NP-2 纳米片对不同致病性革兰氏阳性菌和革兰氏阴性菌的抗菌活性。抑菌区的最高值表明α-Ni2P2O7 纳米片具有良好的抗菌性。
{"title":"Investigating the electrochemical and antibacterial activities of nickel pyrophosphate [a-Ni2P2O7] nanostructures","authors":"A Juliet Christina Mary, M Santhanalakshmi, L Lavanya","doi":"10.1088/2043-6262/ad09c5","DOIUrl":"https://doi.org/10.1088/2043-6262/ad09c5","url":null,"abstract":"Nickel pyrophosphate nanostructures have been synthesized by a simple co-precipitation method. Annealing temperature affected the crystal structure formation of <italic toggle=\"yes\">α</italic>-Ni<sub>2</sub>P<sub>2</sub>O<sub>7</sub> and altered the surface morphology. By increasing the annealing temperature from 350 °C to 900 °C, the morphology of the material varies from irregularly shaped agglomerated particles to dumbbell-shaped nanoparticles respectively. The electrochemical performance of <italic toggle=\"yes\">α</italic>-Ni<sub>2</sub>P<sub>2</sub>O<sub>7</sub> nanoflakes (NP-2) and dumbbell-shaped (NP-3) nanoparticles is tested at 1 M KOH electrolyte solution, which provides the maximum specific capacitance of 146 and 121 F g<sup>−1</sup> at a current density of 0.8 A g<sup>−1</sup> respectively. Furthermore, the antibacterial activity of NP-2 nanoflakes is tested against different pathogenic Gram-positive and Gram-negative bacteria. The highest value of the inhibition zone exhibits the good antibiotic nature of the <italic toggle=\"yes\">α</italic>-Ni<sub>2</sub>P<sub>2</sub>O<sub>7</sub> nanoflakes.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"106 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692997","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 : 2023-11-16DOI: 10.1088/2043-6262/ad08a1
Diep Ngoc Le, Linh Duy Nguyen, Dong Duy Tran, Tan Le Hoang Doan, Chien Mau Dang, Tin Chanh Duc Doan
This paper presents the preparation of a modified polyvinylpyrrolidone (PVP)/graphene mixture and evaluates its adsorption capacity for heavy metal ions in water. Graphene with a high specific surface area of about 362 m2 g−1 was obtained through the thermal separation of graphite oxide (GO), which had been synthesised from graphite by the Hummer method. The graphene-PVP blend was prepared by dispersing the graphene into a PVP solution and then crosslinking it to prevent washout by water. This crosslinking ensured a well-dispersed and stable graphene-PVP blend. The maximum adsorption capacity of graphene-PVP for Cu2+ and Cd2+ ions was found to be 158 mg g−1 and 134 mg g−1, respectively, at pH 3 and a contact time of 30 min. The experimental results were found to be consistent with Langmuir and pseudo-second-order kinetic models. The study further reveals that the adsorption mechanism of Cu2+ and Cd2+ ions on graphene-PVP follows an ion exchange mechanism, driven by strong interactions between PVP and metal ions. The study provides an easy, low-cost, and eco-friendly method to produce highly adsorptive graphene-PVP materials.
{"title":"Blend of polyvinylpyrrolidone/thermally reduced graphene for adsorption of heavy metal ions in water","authors":"Diep Ngoc Le, Linh Duy Nguyen, Dong Duy Tran, Tan Le Hoang Doan, Chien Mau Dang, Tin Chanh Duc Doan","doi":"10.1088/2043-6262/ad08a1","DOIUrl":"https://doi.org/10.1088/2043-6262/ad08a1","url":null,"abstract":"This paper presents the preparation of a modified polyvinylpyrrolidone (PVP)/graphene mixture and evaluates its adsorption capacity for heavy metal ions in water. Graphene with a high specific surface area of about 362 m<sup>2</sup> g<sup>−1</sup> was obtained through the thermal separation of graphite oxide (GO), which had been synthesised from graphite by the Hummer method. The graphene-PVP blend was prepared by dispersing the graphene into a PVP solution and then crosslinking it to prevent washout by water. This crosslinking ensured a well-dispersed and stable graphene-PVP blend. The maximum adsorption capacity of graphene-PVP for Cu<sup>2+</sup> and Cd<sup>2+</sup> ions was found to be 158 mg g<sup>−1</sup> and 134 mg g<sup>−1</sup>, respectively, at pH 3 and a contact time of 30 min. The experimental results were found to be consistent with Langmuir and pseudo-second-order kinetic models. The study further reveals that the adsorption mechanism of Cu<sup>2+</sup> and Cd<sup>2+</sup> ions on graphene-PVP follows an ion exchange mechanism, driven by strong interactions between PVP and metal ions. The study provides an easy, low-cost, and eco-friendly method to produce highly adsorptive graphene-PVP materials.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"1 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692324","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 : 2023-11-16DOI: 10.1088/2043-6262/ad09c6
Dinh Trung Nguyen, Hai Phuong Doan, Thi Kim Ngan Tran, Chan Khon Huynh, Ngoc Quyen Tran, Le Hang Dang
In recent years, nanomaterials have been intensively studied and applied in various fields, including pharmaceutical applications. This platform can act as a carrier for anticancer drugs or for insoluble bioactive compounds. To increase the stability and prolong the effect of anticancer drugs, we have incorporated a sulfated polysaccharide fucoidan (Fu) into PAMAM dendrimer G3.0 to form a G3.0-Fu complex. Then, a nano-sized encapsulated anticancer drug, methotrexate (MTX), was successfully embedded in the synthesised dendrimer complex namely G3.0-Fu/MTX. Newly synthesised G3.0-Fu/MTX was characterised by transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential measurement.Additionally, the loading efficiency of MTX was assessed via UV spectroscopy. Our findings revealed that upon combining with Fu, the G3.0 nanoparticle size increased from 4.3 ± 1.1 nm to 56 ± 6 nm. The changes in zeta potential aligned with drug entrapment efficiency and the results from TEM and DLS. The drug release activity of G3.0-Fu/MTX was increased compared to free MTX after 24 h. G3.0-Fu also showed high cytocompatibility in fibroblast cells. Taken together, the G3.0-Fu could be used to increase the encapsulation of several kinds of hydrophobic drugs and G3.0-Fu/MTX could be further studied in rheumatoid arthritis treatment.
{"title":"Fucoidan and dendrimer-based nanocapsule exhibiting effectiveness in methotrexate controlled delivery towards rheumatoid arthritis treatment","authors":"Dinh Trung Nguyen, Hai Phuong Doan, Thi Kim Ngan Tran, Chan Khon Huynh, Ngoc Quyen Tran, Le Hang Dang","doi":"10.1088/2043-6262/ad09c6","DOIUrl":"https://doi.org/10.1088/2043-6262/ad09c6","url":null,"abstract":"In recent years, nanomaterials have been intensively studied and applied in various fields, including pharmaceutical applications. This platform can act as a carrier for anticancer drugs or for insoluble bioactive compounds. To increase the stability and prolong the effect of anticancer drugs, we have incorporated a sulfated polysaccharide fucoidan (Fu) into PAMAM dendrimer G3.0 to form a G3.0-Fu complex. Then, a nano-sized encapsulated anticancer drug, methotrexate (MTX), was successfully embedded in the synthesised dendrimer complex namely G3.0-Fu/MTX. Newly synthesised G3.0-Fu/MTX was characterised by transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential measurement.Additionally, the loading efficiency of MTX was assessed via UV spectroscopy. Our findings revealed that upon combining with Fu, the G3.0 nanoparticle size increased from 4.3 ± 1.1 nm to 56 ± 6 nm. The changes in zeta potential aligned with drug entrapment efficiency and the results from TEM and DLS. The drug release activity of G3.0-Fu/MTX was increased compared to free MTX after 24 h. G3.0-Fu also showed high cytocompatibility in fibroblast cells. Taken together, the G3.0-Fu could be used to increase the encapsulation of several kinds of hydrophobic drugs and G3.0-Fu/MTX could be further studied in rheumatoid arthritis treatment.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"85 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692268","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 : 2023-11-15DOI: 10.1088/2043-6262/ad09c4
Tri Bao Ngoc Pham, Thuy Ngoc Thi Vo
The photoluminescence (PL) properties of nitrogen-doped graphene quantum dots (NGQDs) are highly dependent on reaction parameters. In this study, we developed new and fast protocols to surface passivate NGQDs with polyethylene glycol (PEG) using microwave irradiation. The resulting NGQDs-PEG exhibited highly stable PL with an emission peak at 424 nm when excited at 325 nm. The PL intensity of NGQDs with PEG increased with the volume of capping agents due to the enhancing luminescence effect of the surface functional group of polyethylene glycol. The optimal PEG amount of 2 wt% was found to improve the PL effect of NGQDs. Interestingly, the surface passivation of NGQDs with PEG enabled the NGQDs to exhibit strong PL performance across varying pH environments (from acidic to alkaline), addressing the issue of quenching of quantum dots in biological environments. Our research also focused on the ultrafast synthesis of NGQDs, where process parameters such as power value, catalyst volume, and reaction time were identified as important factors affecting NGQD luminescence. Our results showed that the optimal microwave power was 640 W, lower than that used in previous synthesis methods. Increasing the volume of catalyst promoted faster NGQD formation. The optimal reaction time was found to be 5 min, catalyst volume of 5 ml resulted in the highest PL intensity of NGQDs.
{"title":"Enhancing photoluminescence performance and pH photostability of nitrogen-doped graphene quantum dots via surface-passivated by polyethylene glycol","authors":"Tri Bao Ngoc Pham, Thuy Ngoc Thi Vo","doi":"10.1088/2043-6262/ad09c4","DOIUrl":"https://doi.org/10.1088/2043-6262/ad09c4","url":null,"abstract":"The photoluminescence (PL) properties of nitrogen-doped graphene quantum dots (NGQDs) are highly dependent on reaction parameters. In this study, we developed new and fast protocols to surface passivate NGQDs with polyethylene glycol (PEG) using microwave irradiation. The resulting NGQDs-PEG exhibited highly stable PL with an emission peak at 424 nm when excited at 325 nm. The PL intensity of NGQDs with PEG increased with the volume of capping agents due to the enhancing luminescence effect of the surface functional group of polyethylene glycol. The optimal PEG amount of 2 wt% was found to improve the PL effect of NGQDs. Interestingly, the surface passivation of NGQDs with PEG enabled the NGQDs to exhibit strong PL performance across varying pH environments (from acidic to alkaline), addressing the issue of quenching of quantum dots in biological environments. Our research also focused on the ultrafast synthesis of NGQDs, where process parameters such as power value, catalyst volume, and reaction time were identified as important factors affecting NGQD luminescence. Our results showed that the optimal microwave power was 640 W, lower than that used in previous synthesis methods. Increasing the volume of catalyst promoted faster NGQD formation. The optimal reaction time was found to be 5 min, catalyst volume of 5 ml resulted in the highest PL intensity of NGQDs.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"28 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692133","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 : 2023-11-15DOI: 10.1088/2043-6262/ad095b
Thanh-Binh Nguyen, Nguyen Thanh Trung, Nguyen Thanh Vinh, Vu Thi Hong Hanh
This study proposes a facile method for superhydrophobic and slippery-infused porous surfaces for water repellency and anti-icing purposes. Both adhesion force and time delaying were systematically investigated, showing their strong dependence on surface parameters and slipperiness. The uniform patterns of nanoscale textures inspired by rose leaf structure have been generated on silicon wafers using the plasma etching process. We believe the lower real contact area can play a dual role in the icing mechanism including reducing heat transfer and adhesion force attributed to the projected area. On the other hand, slipperiness plays an important role in reducing adhesion strength and preventing ice nucleation. The slippery superhydrophobic surface demonstrates outstanding in reducing the adhesion strength while documenting several times lower compared to bare Si, superhydrophobic Si, and slippery Si surfaces. In addition, the rational combination facilitates the efficient function after a number of test cycles, illustrating the mechanical anti-corrosion properties. The results lead to understanding the role of the icing process and designing the anti-icing structure.
{"title":"Anti-corrosion and icephobic approach on rose leaf biomimetic surface","authors":"Thanh-Binh Nguyen, Nguyen Thanh Trung, Nguyen Thanh Vinh, Vu Thi Hong Hanh","doi":"10.1088/2043-6262/ad095b","DOIUrl":"https://doi.org/10.1088/2043-6262/ad095b","url":null,"abstract":"This study proposes a facile method for superhydrophobic and slippery-infused porous surfaces for water repellency and anti-icing purposes. Both adhesion force and time delaying were systematically investigated, showing their strong dependence on surface parameters and slipperiness. The uniform patterns of nanoscale textures inspired by rose leaf structure have been generated on silicon wafers using the plasma etching process. We believe the lower real contact area can play a dual role in the icing mechanism including reducing heat transfer and adhesion force attributed to the projected area. On the other hand, slipperiness plays an important role in reducing adhesion strength and preventing ice nucleation. The slippery superhydrophobic surface demonstrates outstanding in reducing the adhesion strength while documenting several times lower compared to bare Si, superhydrophobic Si, and slippery Si surfaces. In addition, the rational combination facilitates the efficient function after a number of test cycles, illustrating the mechanical anti-corrosion properties. The results lead to understanding the role of the icing process and designing the anti-icing structure.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"28 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692267","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 : 2023-11-15DOI: 10.1088/2043-6262/ad095d
Sushma M, Mahaboob Pasha U, Jai Kumar B, H M Mahesh, G Nagaraju
Aqueous ZnS quantum dots (QDs) were synthesised via a facile, cost-effective one-pot synthesis method in the ambient environment. To achieve most favourable ratios of thioglycolic acid (TGA):zinc (Zn):sulphide (S), the concentration optimisation by optical spectra (COOS) method was adopted. The x-ray diffraction (XRD) spectra confirmed the zinc-blende (cubic) phase of ZnS quantum dots (QDs), and Scherrer’s method determined that on average, the QDs exhibit a size of 2 nm. The Fourier-transform infrared spectroscopy (FTIR) study shows that characteristic peaks are consistent with the vibrational modes of the TGA ligands, confirming the capping. The quantum dots (QDs) synthesised displayed a significant effect of quantum confinement with blue shift in absorption peaks, compared with bulk ZnS absorption peak. Interestingly, on increasing the concentration of TGA, it resulted in red shift at the absorption edge, shifting from 300 nm to 314 nm. On the other hand, increasing the concentration of cation Zn and anion S ratio led to a blue shift, ranging from 315 to 295 nm, and a red shift, ranging from 280–320 nm, at absorption edges respectively. A prominent emission peak appeared at 428 nm. The application of Brus equation allowed estimating the size of the quantum dots (QDs) to be within the range of 2 to 2.7 nm, which correlated well with the Bohr’s radius of ZnS. This favourable property proposes the use of QDs in various optoelectronic devices.
{"title":"Effect of Zn/S/TGA concentration on the stability and optical properties of TGA capped ZnS quantum dots synthesized via one pot aqueous synthesis method","authors":"Sushma M, Mahaboob Pasha U, Jai Kumar B, H M Mahesh, G Nagaraju","doi":"10.1088/2043-6262/ad095d","DOIUrl":"https://doi.org/10.1088/2043-6262/ad095d","url":null,"abstract":"Aqueous ZnS quantum dots (QDs) were synthesised via a facile, cost-effective one-pot synthesis method in the ambient environment. To achieve most favourable ratios of thioglycolic acid (TGA):zinc (Zn):sulphide (S), the concentration optimisation by optical spectra (COOS) method was adopted. The x-ray diffraction (XRD) spectra confirmed the zinc-blende (cubic) phase of ZnS quantum dots (QDs), and Scherrer’s method determined that on average, the QDs exhibit a size of 2 nm. The Fourier-transform infrared spectroscopy (FTIR) study shows that characteristic peaks are consistent with the vibrational modes of the TGA ligands, confirming the capping. The quantum dots (QDs) synthesised displayed a significant effect of quantum confinement with blue shift in absorption peaks, compared with bulk ZnS absorption peak. Interestingly, on increasing the concentration of TGA, it resulted in red shift at the absorption edge, shifting from 300 nm to 314 nm. On the other hand, increasing the concentration of cation Zn and anion S ratio led to a blue shift, ranging from 315 to 295 nm, and a red shift, ranging from 280–320 nm, at absorption edges respectively. A prominent emission peak appeared at 428 nm. The application of Brus equation allowed estimating the size of the quantum dots (QDs) to be within the range of 2 to 2.7 nm, which correlated well with the Bohr’s radius of ZnS. This favourable property proposes the use of QDs in various optoelectronic devices.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"69 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138692200","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 : 2023-11-15DOI: 10.1088/2043-6262/ad08a2
Nouha Mastour, Mohsen Jemaï, Said Ridene
In this work we report the effects of the interface coupling, the effective mass, the Hartree and exchange–correlation potential on the total energy in quasi-2D MoS2/WSe2 van der Waals nanostructure. Analytical and numerical solutions of the total energy as a function of carrier density and effective mass are determined without self-consistent calculation. The calculation carefully indicates how the quasi-2D electron gas arises from the interface coupling between MoS2 and WSe2 layers. Moreover, the results showed that the width of the wave function and the length scale between the two materials’ interface decrease with increasing electron density while the corresponding ground state quantisation energy in the z-direction increases considerably. Furthermore, in MoS2 layer with density ns = 4 × 1012 cm−2 this additional separation is approximately 2 nm and 〈z〉 = 1 nm. Due to the disparity in effective mass of electrons and holes in MoS2, the majority of the excess energy is absorbed as kinetic energy by electrons. The comparison with available experimental and DFT calculation indicates that the present work reproduces properly known results for MoS2/WSe2 interface.
{"title":"Coupling and interface effects in MoS2/WSe2 van der Waals nanostructure","authors":"Nouha Mastour, Mohsen Jemaï, Said Ridene","doi":"10.1088/2043-6262/ad08a2","DOIUrl":"https://doi.org/10.1088/2043-6262/ad08a2","url":null,"abstract":"In this work we report the effects of the interface coupling, the effective mass, the Hartree and exchange–correlation potential on the total energy in quasi-2D MoS<sub>2</sub>/WSe<sub>2</sub> van der Waals nanostructure. Analytical and numerical solutions of the total energy as a function of carrier density and effective mass are determined without self-consistent calculation. The calculation carefully indicates how the quasi-2D electron gas arises from the interface coupling between MoS<sub>2</sub> and WSe<sub>2</sub> layers. Moreover, the results showed that the width of the wave function and the length scale between the two materials’ interface decrease with increasing electron density while the corresponding ground state quantisation energy in the z-direction increases considerably. Furthermore, in MoS<sub>2</sub> layer with density <italic toggle=\"yes\">n</italic>\u0000<sub>s</sub> = 4 × 10<sup>12 </sup>cm<sup>−2</sup> this additional separation is approximately 2 nm and 〈z〉 = 1 nm. Due to the disparity in effective mass of electrons and holes in MoS<sub>2</sub>, the majority of the excess energy is absorbed as kinetic energy by electrons. The comparison with available experimental and DFT calculation indicates that the present work reproduces properly known results for MoS<sub>2</sub>/WSe<sub>2</sub> interface.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"43 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138693027","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}
In this study, BSA-stabilized gold nanoparticles and SiO2 @AuNPs nanocomposite were synthesized and then characterized by the TEM imaging method. The average size of BSA-stabilized gold nanoparticles was found to be as small as 13 nm while the SiO2 @AuNPs nanocomposite showed a mean size of 204 nm. The experimental studies revealed that both BSA-stabilized gold nanoparticles and SiO2 @AuNPs nanocomposite exhibit intrinsic peroxidase-like activity. Hence, to explore more precise no their catalytic efficiency and substrate affinity of them, the kinetic characteristics of both nanozymes were quantified using the Menten kinetic model, and the provided results were compared. Upon using TMB as peroxidase substrate, Vmax of 0.022 µM min-1 and a Km of 0.06 mM for the SiO2 @AuNPs nanocomposite was achieved while for the BSA-stabilized gold nanoparticles, a Vmax and Km at about 0.263 μM min-1and 0.03 mM, in order, was estimated. The Vmax of BSA-stabilized gold nanoparticles was 12.0-fold higher than that of SiO2 @AuNPs nanocomposite, revealing that the catalytic efficiency of BSA-stabilized gold nanoparticles is 12.0-fold higher than SiO2 @AuNPs nanocomposite. Besides, the Km value of SiO2 @AuNPs nanocomposite was 2-order higher than that of BSA-stabilized gold nanoparticles, indicating that the substrate affinity toward BSA-stabilized gold nanoparticles is 2.0-order higher than the SiO2 @AuNPs nanocomposite. Since, the active nodes of both nanozymes are same (i.e., gold), the difference between their catalytic efficiency and affinity can be assigned to their different sizes and the ability of the active nodes to bind the substrate. Based on the results of this work, small-size BSA-stabilized gold nanoparticles are characteristically more efficient peroxidase mimic materials than the SiO2 @AuNPs nanocomposite.
{"title":"Experimental Evaluation of Kinetic Characteristics of SiO2@AuNPs Nanocomposite and BSA-stabilized gold Nanoparticles toward Peroxidase-Mediated Reactions","authors":"","doi":"10.33140/ann.07.01.01","DOIUrl":"https://doi.org/10.33140/ann.07.01.01","url":null,"abstract":"In this study, BSA-stabilized gold nanoparticles and SiO2 @AuNPs nanocomposite were synthesized and then characterized by the TEM imaging method. The average size of BSA-stabilized gold nanoparticles was found to be as small as 13 nm while the SiO2 @AuNPs nanocomposite showed a mean size of 204 nm. The experimental studies revealed that both BSA-stabilized gold nanoparticles and SiO2 @AuNPs nanocomposite exhibit intrinsic peroxidase-like activity. Hence, to explore more precise no their catalytic efficiency and substrate affinity of them, the kinetic characteristics of both nanozymes were quantified using the Menten kinetic model, and the provided results were compared. Upon using TMB as peroxidase substrate, Vmax of 0.022 µM min-1 and a Km of 0.06 mM for the SiO2 @AuNPs nanocomposite was achieved while for the BSA-stabilized gold nanoparticles, a Vmax and Km at about 0.263 μM min-1and 0.03 mM, in order, was estimated. The Vmax of BSA-stabilized gold nanoparticles was 12.0-fold higher than that of SiO2 @AuNPs nanocomposite, revealing that the catalytic efficiency of BSA-stabilized gold nanoparticles is 12.0-fold higher than SiO2 @AuNPs nanocomposite. Besides, the Km value of SiO2 @AuNPs nanocomposite was 2-order higher than that of BSA-stabilized gold nanoparticles, indicating that the substrate affinity toward BSA-stabilized gold nanoparticles is 2.0-order higher than the SiO2 @AuNPs nanocomposite. Since, the active nodes of both nanozymes are same (i.e., gold), the difference between their catalytic efficiency and affinity can be assigned to their different sizes and the ability of the active nodes to bind the substrate. Based on the results of this work, small-size BSA-stabilized gold nanoparticles are characteristically more efficient peroxidase mimic materials than the SiO2 @AuNPs nanocomposite.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136132959","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}
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