Pub Date : 2023-08-09DOI: 10.1088/2043-6262/ace713
Nguyen Tăng Sơn, Tu Le Manh, Nguyen Van Hoang, Pham Thi Lanh, Do Dang Trung, Nguyen Van Hieu
Various techniques were employed to prepare a dual support system of CeZrO2 and H-ZSM-5 (80) including physically mixing, co-precipitation and sonochemical methods, which were followed by the deposition of bimetallic Pd and Pt via wet impregnation to obtain the final catalysts. The catalysts were tested in the total methane oxidation between 200 and 500 °C and the most active is the material derived from sonochemical synthesis. This catalyst achieved a remarkable methane conversion of 84% at a low temperature of 300 °C and high Gas Hourly Space Velocity (GHSV) of 100000 ml g−1 h−1. Characterisation using x-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), scanning transmission electron microscope (STEM), Energy-dispersive x-ray spectroscopy (EDS), temperature-programmed reduction (TPR) and x-ray absorption fine structure (XAFS) techniques revealed the intimate distribution of catalyst components and facile redox behaviour of both Pd and CeZrO2 components. The catalysts based on sonochemical CeZrO2 was proven to be relatively stable with only 7% methane conversion loss after 50 h continuously on stream at 300 °C compared to the corresponding 14% witnessed with the commercial TiO2-based material.
采用多种技术制备了CeZrO2和H-ZSM-5（80）的双载体体系，包括物理混合、共沉淀和声化学方法，然后通过湿法浸渍沉积双金属Pd和Pt以获得最终的催化剂。催化剂在200和500°C之间的总甲烷氧化中进行了测试，最具活性的是来自声化学合成的材料。该催化剂在300°C的低温和100000 ml g−1 h−1的高气体时空速（GHSV）下实现了84%的显著甲烷转化率。使用x射线衍射（XRD）、Brunauer–Emmett–Teller（BET）、扫描电子显微镜（SEM）、扫描透射电子显微镜（STEM）、能量色散x射线光谱（EDS）进行表征，程序升温还原（TPR）和x射线吸收精细结构（XAFS）技术揭示了催化剂组分的紧密分布以及Pd和CeZrO2组分的容易氧化还原行为。基于声化学CeZrO2的催化剂被证明是相对稳定的，在300°C下连续运行50小时后，甲烷转化损失仅为7%，而商业TiO2基材料的甲烷转化损失为14%。
{"title":"A bimetallic PdPt catalyst on CeZrO2/H-ZSM-5 dual support with exceptional activity in low temperature methane oxidation","authors":"Nguyen Tăng Sơn, Tu Le Manh, Nguyen Van Hoang, Pham Thi Lanh, Do Dang Trung, Nguyen Van Hieu","doi":"10.1088/2043-6262/ace713","DOIUrl":"https://doi.org/10.1088/2043-6262/ace713","url":null,"abstract":"Various techniques were employed to prepare a dual support system of CeZrO2 and H-ZSM-5 (80) including physically mixing, co-precipitation and sonochemical methods, which were followed by the deposition of bimetallic Pd and Pt via wet impregnation to obtain the final catalysts. The catalysts were tested in the total methane oxidation between 200 and 500 °C and the most active is the material derived from sonochemical synthesis. This catalyst achieved a remarkable methane conversion of 84% at a low temperature of 300 °C and high Gas Hourly Space Velocity (GHSV) of 100000 ml g−1 h−1. Characterisation using x-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), scanning transmission electron microscope (STEM), Energy-dispersive x-ray spectroscopy (EDS), temperature-programmed reduction (TPR) and x-ray absorption fine structure (XAFS) techniques revealed the intimate distribution of catalyst components and facile redox behaviour of both Pd and CeZrO2 components. The catalysts based on sonochemical CeZrO2 was proven to be relatively stable with only 7% methane conversion loss after 50 h continuously on stream at 300 °C compared to the corresponding 14% witnessed with the commercial TiO2-based material.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44463600","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 : 2023-08-08DOI: 10.1088/2043-6262/acebd8
T. Le, Kim Chi Tran, D. Cao, T. Nguyen, T. T. Van
A series of TiO2:xEr powders (with x from 0% to 1% at.) was synthesised by a simple sol–gel process. The structural and optical properties were studied in detail using diffusion reflection spectroscopy, x-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive x-ray spectroscopy, to systematically determine the band edge, morphology, and structural properties of both undoped and Er-doped TiO2 samples. Notably, the introduction of Er dopants in the TiO2 matrix results in a decrease in both the band gap and crystallite size as well as the anatase phase of host matrix TiO2 remained in the anatase phase even at 800 °C. The heat treatment temperature has an insignificant effect on the green/red emission ratio of Er ions. However, this ratio strongly depends on excitation wavelengths corresponding to down-conversion and up-conversion processes. The colour emission of TiO2:Er is easily tunable from green to yellow under different excitations. The emission mechanism of TiO2:Er is proposed based on spectroscopy techniques. These findings reveal that the TiO2:Er powders are potential materials for labelling and photocatalyst applications.
{"title":"Studying the structural and optical properties of Er3+ doped TiO2 powders synthesized by the sol-gel process","authors":"T. Le, Kim Chi Tran, D. Cao, T. Nguyen, T. T. Van","doi":"10.1088/2043-6262/acebd8","DOIUrl":"https://doi.org/10.1088/2043-6262/acebd8","url":null,"abstract":"A series of TiO2:xEr powders (with x from 0% to 1% at.) was synthesised by a simple sol–gel process. The structural and optical properties were studied in detail using diffusion reflection spectroscopy, x-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive x-ray spectroscopy, to systematically determine the band edge, morphology, and structural properties of both undoped and Er-doped TiO2 samples. Notably, the introduction of Er dopants in the TiO2 matrix results in a decrease in both the band gap and crystallite size as well as the anatase phase of host matrix TiO2 remained in the anatase phase even at 800 °C. The heat treatment temperature has an insignificant effect on the green/red emission ratio of Er ions. However, this ratio strongly depends on excitation wavelengths corresponding to down-conversion and up-conversion processes. The colour emission of TiO2:Er is easily tunable from green to yellow under different excitations. The emission mechanism of TiO2:Er is proposed based on spectroscopy techniques. These findings reveal that the TiO2:Er powders are potential materials for labelling and photocatalyst applications.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49147521","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 : 2023-08-08DOI: 10.1088/2043-6262/acebd9
Dwi Nugraheni Rositawati, M. Absor, K. Triyana, I. Santoso
The role of interstitial atomic doping on transport properties of graphene was systematically studied using first-principles density functional theory (DFT). The study revealed that interstitial Au doping results in a p-type transfer of holes to graphene as the dopant concentration increases to 25%, with the Dirac point shifting to the Fermi level and localised states of atomic dopants appearing at the Fermi level and at energy of −1 eV. Ca, Ag and Al interstitial doping induces an n-type transfer of electrons to graphene with the Dirac point moving away from the Fermi level and localised states appearing at the Fermi level and at energy levels of ∼2 eV for Ca, around −3.5 eV for Ag, −3.5 eV and ∼1.6 eV for Al. As the dopant concentration increases further to 50%, the number of holes (or electrons) decreases for all dopants, except for Ca, as the localised state at the Fermi level disappears, and the Dirac point returns towards the Fermi level. Our research provides insights into how to reconcile the localised state and the number of charge carriers that play a significant role in the transport properties of interstitial doped graphene.
利用第一性原理密度泛函理论(DFT)系统地研究了间隙原子掺杂对石墨烯输运性质的影响。研究表明，当Au掺杂浓度增加到25%时，导致空穴向石墨烯的p型转移，狄拉克点转移到费米能级，原子掺杂的局域态出现在费米能级和- 1 eV能量处。钙、Ag)和Al间隙掺杂引起的n型电子转移石墨烯狄拉克点远离费米能级和局部的状态出现在费米能级和能级2∼eV Ca,周围−3.5 eV Ag)−3.5 eV和∼1.6 eV。作为掺杂剂浓度进一步增加50%,孔的数量(或电子)降低掺杂物,除了Ca,费米能级的局部状态消失,狄拉克点回到费米能级。我们的研究为如何调和局域态和在间隙掺杂石墨烯的输运特性中起重要作用的载流子数量提供了见解。
{"title":"Charge transport properties of interstitially doped graphene: a first-principles study","authors":"Dwi Nugraheni Rositawati, M. Absor, K. Triyana, I. Santoso","doi":"10.1088/2043-6262/acebd9","DOIUrl":"https://doi.org/10.1088/2043-6262/acebd9","url":null,"abstract":"The role of interstitial atomic doping on transport properties of graphene was systematically studied using first-principles density functional theory (DFT). The study revealed that interstitial Au doping results in a p-type transfer of holes to graphene as the dopant concentration increases to 25%, with the Dirac point shifting to the Fermi level and localised states of atomic dopants appearing at the Fermi level and at energy of −1 eV. Ca, Ag and Al interstitial doping induces an n-type transfer of electrons to graphene with the Dirac point moving away from the Fermi level and localised states appearing at the Fermi level and at energy levels of ∼2 eV for Ca, around −3.5 eV for Ag, −3.5 eV and ∼1.6 eV for Al. As the dopant concentration increases further to 50%, the number of holes (or electrons) decreases for all dopants, except for Ca, as the localised state at the Fermi level disappears, and the Dirac point returns towards the Fermi level. Our research provides insights into how to reconcile the localised state and the number of charge carriers that play a significant role in the transport properties of interstitial doped graphene.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43083686","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 : 2023-08-07DOI: 10.1088/2043-6262/acebd7
L. Pradhan, S. Rout, Bipin Kumar Parida, S. Mohapatra, R. Sakthivel, D. Behera
SnO2 and 5 wt% Ni doped SnO2 nanoparticles (SnO2:Ni NPs) were successfully synthesised by a template-free hydrothermal method. X-ray diffraction (XRD) patterns depicted polycrystalline nature of the NPs in rutile-type cassiterite phase with dominant (110) and (101) Bragg diffraction peaks. Rietveld refinement of XRD patterns supported single phase tetragonal crystal structure having space group P42/m n m. With Ni doping, crystallite size of NPs decreased from 39 nm to 35 nm whereas lattice strain increased from 3.56 × 10−3 to 3.99 × 10−3. This is attributed to the substitution of Sn4+ ion by Ni2+ ions. The morphology of the SnO2 NPs also changed from regular spherical shape to elongated irregular shape upon Ni doping. The dominant Raman peak obtained at 634 cm−1 matched with the signature peak for rutile SnO2 (Raman A1g mode). Further, we observed disappearance of E g mode due to Ni doping, which indicated the formation of oxygen vacancies. Also, XPS analysis indicated an increase of oxygen vacancy concentration in the doped NPs due to charge imbalance between Sn4+ and Ni2+. The direct optical band gap of SnO2 increased from 3.97 eV to 4.11 eV when doped with 5 wt% Ni and it is ascribed to Burstein–Moss effect. Irrespective of higher optical band gap of SnO2:Ni NPs, they showed enhanced photocatalytic activity to degrade Rhodamine B (RhB) dye molecules under UV-visible irradiation. The first order kinetic reaction rate constants for degradation of RhB were found to be 0.014 min−1 and 0.045 min−1 in case of SnO2 and SnO2:Ni NPs respectively. The enhanced photocatalytic activity in SnO2:Ni NPs is explained by relating to the formation of more oxygen vacancies and chemisorptions of O2 and H2O molecules followed by generation of radicals. This work demonstrates the superiority of SnO2:Ni NPs for use as photocatalytic material for industrial waste water treatment.
{"title":"Analyzing the role of Ni dopant to change the structural, optical and photocatalytic properties of SnO2 nanoparticles","authors":"L. Pradhan, S. Rout, Bipin Kumar Parida, S. Mohapatra, R. Sakthivel, D. Behera","doi":"10.1088/2043-6262/acebd7","DOIUrl":"https://doi.org/10.1088/2043-6262/acebd7","url":null,"abstract":"SnO2 and 5 wt% Ni doped SnO2 nanoparticles (SnO2:Ni NPs) were successfully synthesised by a template-free hydrothermal method. X-ray diffraction (XRD) patterns depicted polycrystalline nature of the NPs in rutile-type cassiterite phase with dominant (110) and (101) Bragg diffraction peaks. Rietveld refinement of XRD patterns supported single phase tetragonal crystal structure having space group P42/m n m. With Ni doping, crystallite size of NPs decreased from 39 nm to 35 nm whereas lattice strain increased from 3.56 × 10−3 to 3.99 × 10−3. This is attributed to the substitution of Sn4+ ion by Ni2+ ions. The morphology of the SnO2 NPs also changed from regular spherical shape to elongated irregular shape upon Ni doping. The dominant Raman peak obtained at 634 cm−1 matched with the signature peak for rutile SnO2 (Raman A1g mode). Further, we observed disappearance of E g mode due to Ni doping, which indicated the formation of oxygen vacancies. Also, XPS analysis indicated an increase of oxygen vacancy concentration in the doped NPs due to charge imbalance between Sn4+ and Ni2+. The direct optical band gap of SnO2 increased from 3.97 eV to 4.11 eV when doped with 5 wt% Ni and it is ascribed to Burstein–Moss effect. Irrespective of higher optical band gap of SnO2:Ni NPs, they showed enhanced photocatalytic activity to degrade Rhodamine B (RhB) dye molecules under UV-visible irradiation. The first order kinetic reaction rate constants for degradation of RhB were found to be 0.014 min−1 and 0.045 min−1 in case of SnO2 and SnO2:Ni NPs respectively. The enhanced photocatalytic activity in SnO2:Ni NPs is explained by relating to the formation of more oxygen vacancies and chemisorptions of O2 and H2O molecules followed by generation of radicals. This work demonstrates the superiority of SnO2:Ni NPs for use as photocatalytic material for industrial waste water treatment.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47659368","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 : 2023-08-07DOI: 10.1088/2043-6262/acebd4
O. Smirnov, V. Dzhagan, O. Yeshchenko, M. Kovalenko, O. Kapush, M. Vuichyk, V. Dzhagan, N. Mazur, V. Kalynovskyi, M. Skoryk, V. Yukhymchuk
Perspective applications of Ag nanoparticles (NPs) stimulate intense research on their affordable synthesis, including green routes. The use of fungi extracts has advantages over other organisms, because of their relatively easy isolation and higher efficiency in a reduction of metal ions and NP formation. Here we report mycosynthesis of AgNPs based on Ganoderma lucidum fruit body extract with different pH values as the bioreducing and stabilising agent. Stable NPs colloids with distinct plasmonic resonance peaking at 408–418 nm are obtained by using photoreduction in a broad pH range (5 to 11). Synthesis efficiency drops only at very acidic conditions, pH = 2.5. The NP size and morphology are studied by dynamic light scattering and scanning electron microscopy. An analysis of FTIR spectra of pure analyte and NP sample indicates that stabilisation of the AgNPs by the components of Ganoderma lucidum extract may take place via forming chemical bonds with the NP surface. These bio-friendly AgNPs are both optically and chemically active, as inferred from surface-enhanced Raman scattering of a standard dye analytes and charge transfer-induced quenching of the photoluminescence of both dye and inorganic NPs, and can be studied for various applications which require direct access to the AgNP surface.
{"title":"Effect of pH of Ganoderma lucidum aqueous extract on green synthesis of silver nanoparticles","authors":"O. Smirnov, V. Dzhagan, O. Yeshchenko, M. Kovalenko, O. Kapush, M. Vuichyk, V. Dzhagan, N. Mazur, V. Kalynovskyi, M. Skoryk, V. Yukhymchuk","doi":"10.1088/2043-6262/acebd4","DOIUrl":"https://doi.org/10.1088/2043-6262/acebd4","url":null,"abstract":"Perspective applications of Ag nanoparticles (NPs) stimulate intense research on their affordable synthesis, including green routes. The use of fungi extracts has advantages over other organisms, because of their relatively easy isolation and higher efficiency in a reduction of metal ions and NP formation. Here we report mycosynthesis of AgNPs based on Ganoderma lucidum fruit body extract with different pH values as the bioreducing and stabilising agent. Stable NPs colloids with distinct plasmonic resonance peaking at 408–418 nm are obtained by using photoreduction in a broad pH range (5 to 11). Synthesis efficiency drops only at very acidic conditions, pH = 2.5. The NP size and morphology are studied by dynamic light scattering and scanning electron microscopy. An analysis of FTIR spectra of pure analyte and NP sample indicates that stabilisation of the AgNPs by the components of Ganoderma lucidum extract may take place via forming chemical bonds with the NP surface. These bio-friendly AgNPs are both optically and chemically active, as inferred from surface-enhanced Raman scattering of a standard dye analytes and charge transfer-induced quenching of the photoluminescence of both dye and inorganic NPs, and can be studied for various applications which require direct access to the AgNP surface.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45934573","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 : 2023-08-01DOI: 10.1088/2043-6262/ace8fc
Thanh Liem Pham, H. Le, M. Le, T. P. Vu, V. Tran
Silicon-based materials such as pure silicon (Si), silicon monoxide (SiO), silica (SiO2), are considered promising anode for future high power energy Li-ion batteries. Among them, SiO2 has garnered attention owing to its outstanding features such as high theoretical capacity (1961 mAh g−1), abundant reserve, and low-cost processing. However, the large expansion and shrinkage of the Si and SiO2 volume during lithiation/delithiation reaction are still the main barriers for practical application. In this study, SiO2 derived from rice husks and activated by KOH displayed a nanoporous structure with a porous matrix carbon that can absorb the volume expansion during lithiation process and facilitate the diffusion of Li+ ion along the pores to minimise the dendrite growth at the local area. Through activation treatment, the surface area of SiO2 increases up to 278.875 m2 g−1 with a pore volume of 0.191 cm3 g−1 and the average pore diameter is about 0.771 nm. The cycling results showed that rice husk ash mixed with KOH at a ratio of 1:0.5 offered the best capacity retention of SiO2/C anode material in half-cell. In full-cell configuration of SiO2/C||LiFePO4, the the negative electrode/positive electrode capacity ratio (N/P) ratio of 1.2 exhibited the most stable performance with the highest capacity retention.
硅基材料，如纯硅（Si）、一氧化硅（SiO）、二氧化硅（SiO2），被认为是未来高功率能量锂离子电池的有前途的阳极。其中，SiO2因其理论容量高（1961 mAh g−1）、储量丰富、加工成本低等突出特点而备受关注。然而，在锂化/脱锂反应过程中，Si和SiO2体积的大膨胀和大收缩仍然是实际应用的主要障碍。在本研究中，从稻壳中提取并经KOH活化的SiO2显示出具有多孔基质碳的纳米多孔结构，该结构可以吸收锂化过程中的体积膨胀，并促进Li+离子沿孔的扩散，以最大限度地减少局部区域的枝晶生长。通过活化处理，SiO2的表面积增加到278.875 m2 g−1，孔体积为0.191 cm3 g−1。平均孔径约为0.771 nm。循环试验结果表明，稻壳灰与KOH以1:0.5的比例混合，可使SiO2/C阳极材料在半电池中保持最佳的容量。在SiO2/C||LiFePO4的全电池配置中，1.2的负电极/正电极容量比（N/P）表现出最稳定的性能和最高的容量保持率。
{"title":"Preparation of nanoporous SiO2/C derived from rice husk as anode material in SiO2/C||LiFePO4 full-cell through alkaline activation treatment","authors":"Thanh Liem Pham, H. Le, M. Le, T. P. Vu, V. Tran","doi":"10.1088/2043-6262/ace8fc","DOIUrl":"https://doi.org/10.1088/2043-6262/ace8fc","url":null,"abstract":"Silicon-based materials such as pure silicon (Si), silicon monoxide (SiO), silica (SiO2), are considered promising anode for future high power energy Li-ion batteries. Among them, SiO2 has garnered attention owing to its outstanding features such as high theoretical capacity (1961 mAh g−1), abundant reserve, and low-cost processing. However, the large expansion and shrinkage of the Si and SiO2 volume during lithiation/delithiation reaction are still the main barriers for practical application. In this study, SiO2 derived from rice husks and activated by KOH displayed a nanoporous structure with a porous matrix carbon that can absorb the volume expansion during lithiation process and facilitate the diffusion of Li+ ion along the pores to minimise the dendrite growth at the local area. Through activation treatment, the surface area of SiO2 increases up to 278.875 m2 g−1 with a pore volume of 0.191 cm3 g−1 and the average pore diameter is about 0.771 nm. The cycling results showed that rice husk ash mixed with KOH at a ratio of 1:0.5 offered the best capacity retention of SiO2/C anode material in half-cell. In full-cell configuration of SiO2/C||LiFePO4, the the negative electrode/positive electrode capacity ratio (N/P) ratio of 1.2 exhibited the most stable performance with the highest capacity retention.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44478153","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 : 2023-07-28DOI: 10.1088/2043-6262/ace8f8
M. Chand, Arun Singh Rawat, M. Khanuja, S. Rawat
In the work, we developed a novel visible-light-driven photocatalyst WSe2/ZnIn2S4 (ZIS) nanocomposite and performed a comparative dye degradation study on cationic (Malachite green, MG) and anionic (Congo red, CR and Orange-g, OG) dyes. WSe2/ZIS nanocomposite was synthesised by the benign chemical aqueous solution method, under low temperature and pressure. The crystal structure and surface morphology of WSe2 and WSe2/ZIS nanocomposite were studied using X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscope (FESEM), respectively. The optical properties of sample were examined using the UV–vis spectrophotometer and the obtained value of band-gap of WSe2 and WSe2/ZIS was about 1.76 and 2.0 eV, respectively. The WSe2/ZIS nanocomposite displays superior photocatalytic activity compared to bare WSe2 due to optimised surface charge and optical appealing characteristics of WSe2 powder, on the incorporation of ZIS. Pseudo-first-order and second-order rate kinetics were also studied and the result revealed that second-order model fitted well and the overall adsorption process is dominated by the chemisorption process. Scavenger tests were conducted to determine the active species ( O2⋅− ) in photocatalysis mechanics, and the reusability of the nanocomposite was evaluated over 5 cycles. The photocatalytic study result demonstrated that WSe2/ZIS nanocomposite might be employed as an efficient, highly stable photocatalyst for the dye degradation application.
{"title":"Enhancing photocatalytic performance: a study of anionic (congo red, orange-g) and cationic (malachite green) dye degradation using WSe2 and WSe2/ZnIn2S4 nanocomposite","authors":"M. Chand, Arun Singh Rawat, M. Khanuja, S. Rawat","doi":"10.1088/2043-6262/ace8f8","DOIUrl":"https://doi.org/10.1088/2043-6262/ace8f8","url":null,"abstract":"In the work, we developed a novel visible-light-driven photocatalyst WSe2/ZnIn2S4 (ZIS) nanocomposite and performed a comparative dye degradation study on cationic (Malachite green, MG) and anionic (Congo red, CR and Orange-g, OG) dyes. WSe2/ZIS nanocomposite was synthesised by the benign chemical aqueous solution method, under low temperature and pressure. The crystal structure and surface morphology of WSe2 and WSe2/ZIS nanocomposite were studied using X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscope (FESEM), respectively. The optical properties of sample were examined using the UV–vis spectrophotometer and the obtained value of band-gap of WSe2 and WSe2/ZIS was about 1.76 and 2.0 eV, respectively. The WSe2/ZIS nanocomposite displays superior photocatalytic activity compared to bare WSe2 due to optimised surface charge and optical appealing characteristics of WSe2 powder, on the incorporation of ZIS. Pseudo-first-order and second-order rate kinetics were also studied and the result revealed that second-order model fitted well and the overall adsorption process is dominated by the chemisorption process. Scavenger tests were conducted to determine the active species ( O2⋅− ) in photocatalysis mechanics, and the reusability of the nanocomposite was evaluated over 5 cycles. The photocatalytic study result demonstrated that WSe2/ZIS nanocomposite might be employed as an efficient, highly stable photocatalyst for the dye degradation application.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47768114","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 : 2023-07-25DOI: 10.1088/2043-6262/ace711
M. Saied, A. Nour
Polymethyl methacrylate (PMMA)/Palm oil/ZnO nanocomposite films of concentrations 0, 0.5, 1, 2, 5, 10, and 15 wt% were prepared by solution casting technique. Tween 80 was used as a surfactant. The prepared films were characterised by different techniques in addition to antimicrobial and cytotoxicity tests. The scanning electron microscope (SEM) micrographs of fractured surfaces of the films showed that palm oil (PO) and Tween 80 enhanced ZnO NPs dispersion. An excess ZnO loading led to polymer saturation with ZnO NPs which accumulate on PMMA surface. X-ray diffraction (XRD) measurements confirmed SEM results as the crystallinity increased by ZnO NPs loading and decreased by excess loading. In addition, the presence of PO and Tween 80 enhanced thermal stability of pure PMMA and the optimum concentration is 0.5 wt% ZnO NPs. Further, the permittivity (ε′), dielectric loss (ε′′), and electrical conductivity (σ) were investigated. It was found that PO addition increased the values of ε′, ε′′, and σ of PMMA. Upon ZnO loading, these values increased up to 10 wt% ZnO NPs then decreased upon reaching 15 wt% ZnO NPs. The conductivity values revealed that the prepared nanocomposites can perform as antistatic materials for lower ZnO content and electrostatic dissipation application at 10 wt% ZnO. The antimicrobial and cytotoxicity studies revealed that the prepared films are nontoxic and the antimicrobial properties of the films against Staphylococcus aureus, Enterococcus faecalis and Candida albicans were enhanced by PO and ZnO NPs addition.
{"title":"Preparation and characterization of PMMA/ZnO nanocomposites for antistatic and biomedical applications","authors":"M. Saied, A. Nour","doi":"10.1088/2043-6262/ace711","DOIUrl":"https://doi.org/10.1088/2043-6262/ace711","url":null,"abstract":"Polymethyl methacrylate (PMMA)/Palm oil/ZnO nanocomposite films of concentrations 0, 0.5, 1, 2, 5, 10, and 15 wt% were prepared by solution casting technique. Tween 80 was used as a surfactant. The prepared films were characterised by different techniques in addition to antimicrobial and cytotoxicity tests. The scanning electron microscope (SEM) micrographs of fractured surfaces of the films showed that palm oil (PO) and Tween 80 enhanced ZnO NPs dispersion. An excess ZnO loading led to polymer saturation with ZnO NPs which accumulate on PMMA surface. X-ray diffraction (XRD) measurements confirmed SEM results as the crystallinity increased by ZnO NPs loading and decreased by excess loading. In addition, the presence of PO and Tween 80 enhanced thermal stability of pure PMMA and the optimum concentration is 0.5 wt% ZnO NPs. Further, the permittivity (ε′), dielectric loss (ε′′), and electrical conductivity (σ) were investigated. It was found that PO addition increased the values of ε′, ε′′, and σ of PMMA. Upon ZnO loading, these values increased up to 10 wt% ZnO NPs then decreased upon reaching 15 wt% ZnO NPs. The conductivity values revealed that the prepared nanocomposites can perform as antistatic materials for lower ZnO content and electrostatic dissipation application at 10 wt% ZnO. The antimicrobial and cytotoxicity studies revealed that the prepared films are nontoxic and the antimicrobial properties of the films against Staphylococcus aureus, Enterococcus faecalis and Candida albicans were enhanced by PO and ZnO NPs addition.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47445822","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 : 2023-07-13DOI: 10.1088/2043-6262/ace432
H. T. Pham, Hau Quoc Pham, Q. Huynh, Thao Ngoc Nguyen, N. Huynh, Thanh-Quang Nguyen, T. Huynh
Constructing robust support plays a key role in governing the overall catalytic efficiency of metal-based catalysts for electrochemical reactions in sustainable energy-related conversion systems. We herein use a solvothermal method to assemble Ti0.9Ir0.1O2-Activated C composites, exhibiting high surface area and electrical conductivity compared to the pure TiO2 material. The material characterisations and electrochemical behaviours of the as-obtained composites are systemically studied by XRD, FE-SEM-EDX mapping, FT-IR, XPS, BET, four-point technique, cyclic voltammetry, etc Notably, the effect of composition on the physical and electrochemical properties of the as-made composites is also explored, which indicated the significant improvement in surface area and electrical conductivity with increasing carbon content, while a reverse trend is observed in the electrochemical durability. Among all studied composites, the Ti0.9Ir0.1O2-Activated C (50:50 wt%) composite can be a suitable support for metal-based catalysts due to its balance in physical properties (electrical conductivity of 1.5 S cm−1 and surface area of 152.12 m2 g−1) and electrochemical corrosion resistance (high durability after 2000-cycling ADT). This study can open up an efficient strategy to enhance the catalytic performance of electrochemical processes.
{"title":"Synthesis and characterization of Ti0.9Ir0.1O2-activated carbon composite as a promising support for catalysts in electrochemical energy conversion","authors":"H. T. Pham, Hau Quoc Pham, Q. Huynh, Thao Ngoc Nguyen, N. Huynh, Thanh-Quang Nguyen, T. Huynh","doi":"10.1088/2043-6262/ace432","DOIUrl":"https://doi.org/10.1088/2043-6262/ace432","url":null,"abstract":"Constructing robust support plays a key role in governing the overall catalytic efficiency of metal-based catalysts for electrochemical reactions in sustainable energy-related conversion systems. We herein use a solvothermal method to assemble Ti0.9Ir0.1O2-Activated C composites, exhibiting high surface area and electrical conductivity compared to the pure TiO2 material. The material characterisations and electrochemical behaviours of the as-obtained composites are systemically studied by XRD, FE-SEM-EDX mapping, FT-IR, XPS, BET, four-point technique, cyclic voltammetry, etc Notably, the effect of composition on the physical and electrochemical properties of the as-made composites is also explored, which indicated the significant improvement in surface area and electrical conductivity with increasing carbon content, while a reverse trend is observed in the electrochemical durability. Among all studied composites, the Ti0.9Ir0.1O2-Activated C (50:50 wt%) composite can be a suitable support for metal-based catalysts due to its balance in physical properties (electrical conductivity of 1.5 S cm−1 and surface area of 152.12 m2 g−1) and electrochemical corrosion resistance (high durability after 2000-cycling ADT). This study can open up an efficient strategy to enhance the catalytic performance of electrochemical processes.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45216751","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 : 2023-07-13DOI: 10.1088/2043-6262/ace3b9
Nguyet Ho Minh, Cuong Vu Manh, Anh Le Thi Van, Duong Le Thi Thuy
Honokiol, a plant bioactive compound, is derived from the Magnolia genus and has several pharmacological advantages including anti-inflammatory, antiviral, neuromodulatory and anti-tumour activities. However, honokiol’s pharmaceutical utility is constrained by its poor solubility in water. Nanotechnology has been widely used to address this issue to make anticancer medications more effective by increasing their water solubility. Furthermore, the stability of the nanoparticles is one of the most important factors affecting the safety and efficacy of the drug. In this study, honokiol-loaded PLGA − PEG nanoparticles were synthesised and the stability of this nanosystem was evaluated in two conditions that are normal condition and accelerated-aging condition. The parameters used to evaluate the stability of the nanocarrier system include particle size, polydispersity index, zeta potential, morphology, encapsulation efficiency, and loading capacity. All of the samples were stored at three temperatures of 4 °C, 27 °C and 40 °C, and assessed at four times of 0 month, 1 month, 2 months, and 3 months. The physicochemical parameters of nanoparticles after three months of storage showed greater stability at 4 °C compared to 27 °C and 40 °C. There were no significant differences in the parameters of samples stored in three months at 4 °C, meanwhile, the parameters of those stored at 27 °C and 40 °C fluctuated considerably. Therefore, the results show that storing samples at 4 °C allows maintaining the stability of the nanosystem for a long time.
{"title":"Stability of soluble honokiol loaded PLGA-PEG nanoparticles under normal and accelerated-aging conditions","authors":"Nguyet Ho Minh, Cuong Vu Manh, Anh Le Thi Van, Duong Le Thi Thuy","doi":"10.1088/2043-6262/ace3b9","DOIUrl":"https://doi.org/10.1088/2043-6262/ace3b9","url":null,"abstract":"Honokiol, a plant bioactive compound, is derived from the Magnolia genus and has several pharmacological advantages including anti-inflammatory, antiviral, neuromodulatory and anti-tumour activities. However, honokiol’s pharmaceutical utility is constrained by its poor solubility in water. Nanotechnology has been widely used to address this issue to make anticancer medications more effective by increasing their water solubility. Furthermore, the stability of the nanoparticles is one of the most important factors affecting the safety and efficacy of the drug. In this study, honokiol-loaded PLGA − PEG nanoparticles were synthesised and the stability of this nanosystem was evaluated in two conditions that are normal condition and accelerated-aging condition. The parameters used to evaluate the stability of the nanocarrier system include particle size, polydispersity index, zeta potential, morphology, encapsulation efficiency, and loading capacity. All of the samples were stored at three temperatures of 4 °C, 27 °C and 40 °C, and assessed at four times of 0 month, 1 month, 2 months, and 3 months. The physicochemical parameters of nanoparticles after three months of storage showed greater stability at 4 °C compared to 27 °C and 40 °C. There were no significant differences in the parameters of samples stored in three months at 4 °C, meanwhile, the parameters of those stored at 27 °C and 40 °C fluctuated considerably. Therefore, the results show that storing samples at 4 °C allows maintaining the stability of the nanosystem for a long time.","PeriodicalId":7359,"journal":{"name":"Advances in Natural Sciences: Nanoscience and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48129185","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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