Pub Date : 2024-03-01DOI: 10.15251/djnb.2024.191.319
D. Ochoa, J. Guzmán Torres, E. M. Cervantes, J. L. Cavazos, I. Gómez
Due to their chemical and physical properties, this study focuses on the effect of sonication over carbon quantum dots synthesized by means of hydrothermal route, having as precursor the sour lemon juice from Michoacán, Mexico. The exfoliation was carried out with a sonotrode in times of 1, 2 and 3 hours to provide an explanation over the effect of it on the photoluminescence, where it was found that with times of 1 hour, the PL emission is improved resulting from 261 a.u. to 448 a.u. Other characterizations were carried out to confirm the results obtained in PL, where the average particle size was analyzed by SEM, particle sizes ranging from 5 to 11 nm were observed, with an average size of 7.5 nm and to confirm the carbonaceous material, UV-Vis was performed showing a resolved UV absorption band around 340 nm.
{"title":"The effect of sonication on the photoluminescence property of carbon quantum dots synthesized by hydrothermal route","authors":"D. Ochoa, J. Guzmán Torres, E. M. Cervantes, J. L. Cavazos, I. Gómez","doi":"10.15251/djnb.2024.191.319","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.319","url":null,"abstract":"Due to their chemical and physical properties, this study focuses on the effect of sonication over carbon quantum dots synthesized by means of hydrothermal route, having as precursor the sour lemon juice from Michoacán, Mexico. The exfoliation was carried out with a sonotrode in times of 1, 2 and 3 hours to provide an explanation over the effect of it on the photoluminescence, where it was found that with times of 1 hour, the PL emission is improved resulting from 261 a.u. to 448 a.u. Other characterizations were carried out to confirm the results obtained in PL, where the average particle size was analyzed by SEM, particle sizes ranging from 5 to 11 nm were observed, with an average size of 7.5 nm and to confirm the carbonaceous material, UV-Vis was performed showing a resolved UV absorption band around 340 nm.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140272350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.15251/djnb.2024.191.309
S. J. Li, E. Pang, W. J. Zhao
Cu2(OH)2CO3 (cupric carbonate basic, CCB) is a common copper-based semiconductor compound that can absorb the visible light due to its suitable bandgap structure. Here, CCB was synthesized by a one-pot hydrothermal strategy. The catalyst exhibited excellent activation activity of persulfate (PS) supported by visible light irradiation and can degrade tetracycline hydrochloride (TCH) over a wide pH range from 3.0 to 10.0. Under the condition of 0.1 g/L catalyst and 2 mM PS, the removal rate of TCH (30 mg/L) reached 96% after 60 min of visible light irradiation. Coexisting anions (Cl- , HCO3 - , SO4 2- ) had little effect on the TCH degradation. The synergistic effects of CCB combined with PS and visible light were beneficial for the separation of photogenerated hole-electrons and the generation of more free radicals. Electron paramagnetic resonance (EPR) experiments and quenching experiments show that HO∙ and h+ are the predominant species in the catalytic reaction. Thus, this study proposes a promising approach using the CCB/PS/Vis system for wastewater remediation.
{"title":"Photoassisted activation of persulfate by Cu2(OH)2CO3 for the degradation of tetracycline hydrochloride","authors":"S. J. Li, E. Pang, W. J. Zhao","doi":"10.15251/djnb.2024.191.309","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.309","url":null,"abstract":"Cu2(OH)2CO3 (cupric carbonate basic, CCB) is a common copper-based semiconductor compound that can absorb the visible light due to its suitable bandgap structure. Here, CCB was synthesized by a one-pot hydrothermal strategy. The catalyst exhibited excellent activation activity of persulfate (PS) supported by visible light irradiation and can degrade tetracycline hydrochloride (TCH) over a wide pH range from 3.0 to 10.0. Under the condition of 0.1 g/L catalyst and 2 mM PS, the removal rate of TCH (30 mg/L) reached 96% after 60 min of visible light irradiation. Coexisting anions (Cl- , HCO3 - , SO4 2- ) had little effect on the TCH degradation. The synergistic effects of CCB combined with PS and visible light were beneficial for the separation of photogenerated hole-electrons and the generation of more free radicals. Electron paramagnetic resonance (EPR) experiments and quenching experiments show that HO∙ and h+ are the predominant species in the catalytic reaction. Thus, this study proposes a promising approach using the CCB/PS/Vis system for wastewater remediation.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140275265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.15251/djnb.2024.191.283
F. Razzaz, A. Nawaz, A. Ghaffar
Theoretically analysis has been accomplished for the propagating electromagnetic surface waves (EMSWs) at planar ferrite-graphene-ferrite waveguide structure. The characteristics curves are analyzed for the normalized phase and attenuation phase constant against the operating frequency. The impact of different parameters of ferrite and graphene are observed on the normalize phase and attenuation phase constant. In response to these parameters the structured waveguide exhibits the convenient propagation of electromagnetic surface waves with minimal propagation loss in the terahertz frequency region. The proposed waveguide avails position in nanophotonic devices, terahertz filters, highly integrated terahertz devices and communication systems.
{"title":"Tunable properties of graphene loaded waveguide surrounded by magnetic materials","authors":"F. Razzaz, A. Nawaz, A. Ghaffar","doi":"10.15251/djnb.2024.191.283","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.283","url":null,"abstract":"Theoretically analysis has been accomplished for the propagating electromagnetic surface waves (EMSWs) at planar ferrite-graphene-ferrite waveguide structure. The characteristics curves are analyzed for the normalized phase and attenuation phase constant against the operating frequency. The impact of different parameters of ferrite and graphene are observed on the normalize phase and attenuation phase constant. In response to these parameters the structured waveguide exhibits the convenient propagation of electromagnetic surface waves with minimal propagation loss in the terahertz frequency region. The proposed waveguide avails position in nanophotonic devices, terahertz filters, highly integrated terahertz devices and communication systems.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140275149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.15251/djnb.2024.191.295
S. Aldaghfag, Nasarullah, A. Aziz, M. Ishfaq, M. Yaseen, Hafsa, S. Jamshaid
Herein, the investigation is presented to analyze the structural, electronic, optical, and thermoelectric features of Cs2XAgCl6 (X= Sc, Y) by applying the first principles approach. The confirmation of the stable structure of both compounds is reinforced by the negative values of formation enthalpies. The electronic band gaps (Eg) of 3.78/4.86 eV are computed for Cs2ScAgCl6 /Cs2YAgCl6 through Tran-Blaha modified Becke-Johnson (TBmBJ) potential, correspondingly. The tolerance factor(τ) is found as 0.9 for Cs2ScAgCl6 and 1.0 for Cs2YAgCl6 which confirmed the stable cubic nature of both compounds. Optical factors like dielectric-function ε(ω), absorption coefficient α(ω), and others related parameters are analyzed within 0 to 10 eV of energy span. Both compounds demonstrated high absorption in the ultraviolet region, rendering them as well-suited materials for photovoltaic applications. The calculated values of refractive index for Cs2ScAgCl6 and Cs2YAgCl6 indicated super-luminescent characteristics in the ultraviolet region. For thermoelectric (TE) features, electrical conductivity (σ/τ), figure of merit (ZT), power factor (PF), thermal conductivity (k/τ), and Seebeck coefficient (S) are calculated using the BoltzTraP code. According to the findings, both materials are advocated as promising candidates for thermoelectric and optoelectronic applications.
{"title":"First principles insights into Cs2XAgCl6 (X= Sc, Y) compounds for energy harvesting applications","authors":"S. Aldaghfag, Nasarullah, A. Aziz, M. Ishfaq, M. Yaseen, Hafsa, S. Jamshaid","doi":"10.15251/djnb.2024.191.295","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.295","url":null,"abstract":"Herein, the investigation is presented to analyze the structural, electronic, optical, and thermoelectric features of Cs2XAgCl6 (X= Sc, Y) by applying the first principles approach. The confirmation of the stable structure of both compounds is reinforced by the negative values of formation enthalpies. The electronic band gaps (Eg) of 3.78/4.86 eV are computed for Cs2ScAgCl6 /Cs2YAgCl6 through Tran-Blaha modified Becke-Johnson (TBmBJ) potential, correspondingly. The tolerance factor(τ) is found as 0.9 for Cs2ScAgCl6 and 1.0 for Cs2YAgCl6 which confirmed the stable cubic nature of both compounds. Optical factors like dielectric-function ε(ω), absorption coefficient α(ω), and others related parameters are analyzed within 0 to 10 eV of energy span. Both compounds demonstrated high absorption in the ultraviolet region, rendering them as well-suited materials for photovoltaic applications. The calculated values of refractive index for Cs2ScAgCl6 and Cs2YAgCl6 indicated super-luminescent characteristics in the ultraviolet region. For thermoelectric (TE) features, electrical conductivity (σ/τ), figure of merit (ZT), power factor (PF), thermal conductivity (k/τ), and Seebeck coefficient (S) are calculated using the BoltzTraP code. According to the findings, both materials are advocated as promising candidates for thermoelectric and optoelectronic applications.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140278686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-01DOI: 10.15251/djnb.2024.191.53
Y. F. Liu, M. H. Gao, J. Liu, Y. Y. Zhan, Z. W. Gu, C. Y. Li, H. Y. Zhu, F.Y. Du, B. H. Zhang
The Enteromorpha prolifera biochar and 4A zeolite-modified biochar based on different pyrolysis temperatures were prepared. The biochar of good biocompatibility with Bt was selected by studying the effects of different biochar on the survival rate and salt tolerance of Bacillus thuringiensis (Bt). The biochar microspheres loaded with Bt were prepared with sodium alginate, pectin, and chitosan. The effects of the addition of biochar on the particle size and ball formation rate of the microspheres were investigated. The structure of the microspheres was characterized by SEM and FTIR, and the SR of the microspheres under different pH conditions were evaluated. The results showed that 4A zeolite-modified biochar prepared at 500 ℃ (GH500) had good compatibility with Bt, and could improve the salt tolerance of Bt. The prepared microspheres have a uniform shape and particle size, and their swelling characteristics were pH-responsive, the microspheres containing biochar exhibited good swelling properties under alkaline conditions.
{"title":"Preparation of 4A zeolite modified enteromorpha biochar and its application in bacillus thuringiensis microspheres","authors":"Y. F. Liu, M. H. Gao, J. Liu, Y. Y. Zhan, Z. W. Gu, C. Y. Li, H. Y. Zhu, F.Y. Du, B. H. Zhang","doi":"10.15251/djnb.2024.191.53","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.53","url":null,"abstract":"The Enteromorpha prolifera biochar and 4A zeolite-modified biochar based on different pyrolysis temperatures were prepared. The biochar of good biocompatibility with Bt was selected by studying the effects of different biochar on the survival rate and salt tolerance of Bacillus thuringiensis (Bt). The biochar microspheres loaded with Bt were prepared with sodium alginate, pectin, and chitosan. The effects of the addition of biochar on the particle size and ball formation rate of the microspheres were investigated. The structure of the microspheres was characterized by SEM and FTIR, and the SR of the microspheres under different pH conditions were evaluated. The results showed that 4A zeolite-modified biochar prepared at 500 ℃ (GH500) had good compatibility with Bt, and could improve the salt tolerance of Bt. The prepared microspheres have a uniform shape and particle size, and their swelling characteristics were pH-responsive, the microspheres containing biochar exhibited good swelling properties under alkaline conditions.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139637838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-01DOI: 10.15251/djnb.2024.191.65
A. EL-FADL, M. A. M. Hussien, A. S. Soltan, A. Abu-Sehly
Mo1-xCoxS2 (0 ≤ x ≤ 0.1) nanoparticles were successfully synthesized by using a hydrothermal route. The crystal structure of the prepared samples was investigated by Xray diffraction (XRD), emphasizing that all the prepared samples had a hexagonal structure of MoS2, and revealed an increment in the average particle size from 5 to 8 nm with increasing the cobalt ratio. The morphology was examined using scanning electron microscopy (SEM), and the recorded images of pure and cobalt-doped MoS2 show flowerlike architecture clusters. FT-IR spectroscopy was carried out to detect functional groups and stretching and bending vibrations of chemical bonds existing in all the prepared samples, confirming the presence of Mo-O and Co-O-Co characteristic peaks. The chemical composition of the synthesized samples was determined by energy dispersive Xray (EDX) analysis. The results confirmed the presence of Mo, S, and Co, which are consistent with the proposed formation of Mo1-xCoxS2 nanosystems. Optical properties were examined by UV–Visible spectrophotometry, reflecting allowed direct transitions with an energy band gap that decreases from 1.9 eV to 1.53 eV with increasing cobalt concentration. The photocatalytic degradation efficiency of methylene blue (MB) using pure and different ratios of cobalt-doped MoS2 as catalysts was tested under visible light radiation, and it was noticed that the MB degradation increased with increasing cobalt concentration.
采用水热法成功合成了 Mo1-xCoxS2 (0 ≤ x ≤ 0.1) 纳米粒子。通过 X 射线衍射（XRD）研究了所制备样品的晶体结构，结果表明所有制备样品都具有 MoS2 的六方结构，并且随着钴比例的增加，平均粒径从 5 纳米增加到 8 纳米。使用扫描电子显微镜（SEM）对形貌进行了检测，记录的纯 MoS2 和掺钴 MoS2 图像显示出花朵状的结构团簇。傅立叶变换红外光谱检测了所有制备样品中存在的官能团以及化学键的伸缩和弯曲振动，证实了 Mo-O 和 Co-O-Co 特征峰的存在。通过能量色散 X 射线（EDX）分析确定了合成样品的化学成分。结果证实了 Mo、S 和 Co 的存在，这与所提出的 Mo1-xCoxS2 纳米系统的形成相一致。紫外-可见分光光度法检测了其光学特性，结果表明，随着钴浓度的增加，其能带隙从 1.9 eV 减小到 1.53 eV，允许直接跃迁。使用纯 MoS2 和不同比例的掺钴 MoS2 作为催化剂，在可见光辐射下测试了亚甲基蓝（MB）的光催化降解效率。
{"title":"Structure, optical and visible-light photocatalytic performance of Mo1-xCoxS2 (0 ≤ x ≤ 0.1) nanoparticles synthesized by facile hydrothermal method for methylene blue dye degradation","authors":"A. EL-FADL, M. A. M. Hussien, A. S. Soltan, A. Abu-Sehly","doi":"10.15251/djnb.2024.191.65","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.65","url":null,"abstract":"Mo1-xCoxS2 (0 ≤ x ≤ 0.1) nanoparticles were successfully synthesized by using a hydrothermal route. The crystal structure of the prepared samples was investigated by Xray diffraction (XRD), emphasizing that all the prepared samples had a hexagonal structure of MoS2, and revealed an increment in the average particle size from 5 to 8 nm with increasing the cobalt ratio. The morphology was examined using scanning electron microscopy (SEM), and the recorded images of pure and cobalt-doped MoS2 show flowerlike architecture clusters. FT-IR spectroscopy was carried out to detect functional groups and stretching and bending vibrations of chemical bonds existing in all the prepared samples, confirming the presence of Mo-O and Co-O-Co characteristic peaks. The chemical composition of the synthesized samples was determined by energy dispersive Xray (EDX) analysis. The results confirmed the presence of Mo, S, and Co, which are consistent with the proposed formation of Mo1-xCoxS2 nanosystems. Optical properties were examined by UV–Visible spectrophotometry, reflecting allowed direct transitions with an energy band gap that decreases from 1.9 eV to 1.53 eV with increasing cobalt concentration. The photocatalytic degradation efficiency of methylene blue (MB) using pure and different ratios of cobalt-doped MoS2 as catalysts was tested under visible light radiation, and it was noticed that the MB degradation increased with increasing cobalt concentration.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140520854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-01DOI: 10.15251/djnb.2024.191.81
R. Manikandan, D. Thenmuhil, M. Krishnan
Novel aerogel composites were prepared by sol-gel process and dried by adding 5 to 15 weight percentage of cenosphere to silica aerogel prepared by subcritical drying process. Silica-cenosphere aerogels were calcined at 1200ºC, as α-cristobalite phase was formed in silica aerogel at 1200°C. At temperatures less than 1200°C only amorphous silica was found in silica aerogel. Microstructural analysis showed spherical shape in different sizes with micro pores in surface of cenosphere and popcorn-like structure in silica-cenosphere aerogels. Effect of cenosphere addition in silica aerogel was studied by FT-IR. The particle size and distribution of prepared aerogels and cenosphere were analysed by particle size distribution analyser. The average particle size of silica aerogel was found to reduce by increased addition of cenosphere. The nitrogen adsorption studies of cenosphere and silicacenosphere aerogels indicated type II isotherm which represents macroporous/nonporous unrestricted monolayer – multilayer adsorption. The powder flow behaviour of the cenosphere and prepared aerogels were found to be strongly dependent on the particle size and distribution. The compressive strength and thermal conductivity of all the samples were found to be dependent on the porosity and bulk density. Among all the samples, lower density and higher porosity was observed in SC15. The silica aerogel recorded the highest strength value and was reduced by the addition of cenosphere except for SC5. The thermal conductivity was also found to be lowered for silica-cenosphere aerogels than pure silica aerogel and was found suitable for thermal insulation application that do not require strength.
{"title":"Development of silica - cenosphere aerogel composites for thermal insulation applications","authors":"R. Manikandan, D. Thenmuhil, M. Krishnan","doi":"10.15251/djnb.2024.191.81","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.81","url":null,"abstract":"Novel aerogel composites were prepared by sol-gel process and dried by adding 5 to 15 weight percentage of cenosphere to silica aerogel prepared by subcritical drying process. Silica-cenosphere aerogels were calcined at 1200ºC, as α-cristobalite phase was formed in silica aerogel at 1200°C. At temperatures less than 1200°C only amorphous silica was found in silica aerogel. Microstructural analysis showed spherical shape in different sizes with micro pores in surface of cenosphere and popcorn-like structure in silica-cenosphere aerogels. Effect of cenosphere addition in silica aerogel was studied by FT-IR. The particle size and distribution of prepared aerogels and cenosphere were analysed by particle size distribution analyser. The average particle size of silica aerogel was found to reduce by increased addition of cenosphere. The nitrogen adsorption studies of cenosphere and silicacenosphere aerogels indicated type II isotherm which represents macroporous/nonporous unrestricted monolayer – multilayer adsorption. The powder flow behaviour of the cenosphere and prepared aerogels were found to be strongly dependent on the particle size and distribution. The compressive strength and thermal conductivity of all the samples were found to be dependent on the porosity and bulk density. Among all the samples, lower density and higher porosity was observed in SC15. The silica aerogel recorded the highest strength value and was reduced by the addition of cenosphere except for SC5. The thermal conductivity was also found to be lowered for silica-cenosphere aerogels than pure silica aerogel and was found suitable for thermal insulation application that do not require strength.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140525474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-01DOI: 10.15251/djnb.2024.191.107
Q. Li, J. Shang, G. Gu
The VSX/TiO2 composite layer was successfully prepared by adding Na2S and Na3VO4 into electrolytes through micro-arc oxidation (MAO) method. The structure, morphology and tribological properties were analyzed by X-ray diffraction, scanning electron microscopy and 3D true color microscopy. The results show that when the concentration of Na2S is 10-20 g/L, the thickness of VSx/TiO2 composite layer is the thickest, and the friction coefficient and volume wear are the lowest. The VSx/TiO2 composite layer in-situ prepared by MAO can improve the tribological properties of TC4 alloy at high temperature.
通过微弧氧化（MAO）法在电解液中加入 Na2S 和 Na3VO4，成功制备了 VSX/TiO2 复合层。通过 X 射线衍射、扫描电子显微镜和三维真彩显微镜对其结构、形貌和摩擦学性能进行了分析。结果表明，当 Na2S 浓度为 10-20 g/L 时，VSx/TiO2 复合层的厚度最大，摩擦系数和体积磨损最小。通过 MAO 原位制备的 VSx/TiO2 复合层可以改善 TC4 合金在高温下的摩擦学性能。
{"title":"Microstructure and tribological properties of VSx / TiO2 composite layers in-situ prepared on TC4 alloy","authors":"Q. Li, J. Shang, G. Gu","doi":"10.15251/djnb.2024.191.107","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.107","url":null,"abstract":"The VSX/TiO2 composite layer was successfully prepared by adding Na2S and Na3VO4 into electrolytes through micro-arc oxidation (MAO) method. The structure, morphology and tribological properties were analyzed by X-ray diffraction, scanning electron microscopy and 3D true color microscopy. The results show that when the concentration of Na2S is 10-20 g/L, the thickness of VSx/TiO2 composite layer is the thickest, and the friction coefficient and volume wear are the lowest. The VSx/TiO2 composite layer in-situ prepared by MAO can improve the tribological properties of TC4 alloy at high temperature.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139631850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-01DOI: 10.15251/djnb.2024.191.1
J. Li, Y. F. Zhang, Q. Li, X.Y. Ran, Q. Hao, X. L. Guo
Y2O3 coatings were fabricated on using atmospheric plasma spraying (APS). The effects of different process parameters on the microstructure and properties of the coating were analyzed. The results show that the overall morphology of Y2O3 coatings are smooth at high spraying power, low spraying distance and low primary gas flow rate, which is consistent with the change trend of porosity and hardness. The minimum porosity of coating is about 1.4%. The roughness of coatings isn’t sensitive to changes in parameters. Y2O3 coatings have excellent corrosion resistance. The smaller the porosity of Y2O3 coating, the better the corrosion resistance.
{"title":"Influence of atmospheric plasma spraying process parameters on microstructure and properties of yttrium oxide coatings","authors":"J. Li, Y. F. Zhang, Q. Li, X.Y. Ran, Q. Hao, X. L. Guo","doi":"10.15251/djnb.2024.191.1","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.1","url":null,"abstract":"Y2O3 coatings were fabricated on using atmospheric plasma spraying (APS). The effects of different process parameters on the microstructure and properties of the coating were analyzed. The results show that the overall morphology of Y2O3 coatings are smooth at high spraying power, low spraying distance and low primary gas flow rate, which is consistent with the change trend of porosity and hardness. The minimum porosity of coating is about 1.4%. The roughness of coatings isn’t sensitive to changes in parameters. Y2O3 coatings have excellent corrosion resistance. The smaller the porosity of Y2O3 coating, the better the corrosion resistance.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139632799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-01DOI: 10.15251/djnb.2024.191.25
O. Alsalmi, M. M. Saad H.-E.
First-principles DFT calculations by utilizing FP-LAPW under GGA+PBE method are performed to investigate the structural, electronic and optical characteristics of bromide perovskites MGeBr3 (M = Rb, Cs, Fr). It is found that the cubic structure (Pm-3m) and optimized lattice constants are in good agreement with the previous data. Our GGA+PBE results reveal that MGeBr3 show nonmagnetic semiconductor behavior with direct bandgap (Eg = 0.925 eV (M = Rb), 0.898 eV (M = Cs), 0.952 eV (M = Fr)) along the L–L symmetry direction. Formation energy, octahedral ration and tolerance factor for MGeBr3 have also been calculated. The 2-D charge densities confirm that the chemical bonds (Ge2+–Br- ) and (M+–Br- ) follow the covalent and ionic bonding types. Moreover, we have calculated and discussed the optical parameters, dielectric constants, absorption, conductivity and refractivity. The calculated electronic and optical properties show the narrow band-gap, high absorption and semiconductor nature making these inorganic materials suitable for optoelectronics applications.
{"title":"A (GGA+PBE) investigation of MGeBr3 (M = Rb, Cs, Fr) bromide perovskites: structural, electronic, and optical characteristics","authors":"O. Alsalmi, M. M. Saad H.-E.","doi":"10.15251/djnb.2024.191.25","DOIUrl":"https://doi.org/10.15251/djnb.2024.191.25","url":null,"abstract":"First-principles DFT calculations by utilizing FP-LAPW under GGA+PBE method are performed to investigate the structural, electronic and optical characteristics of bromide perovskites MGeBr3 (M = Rb, Cs, Fr). It is found that the cubic structure (Pm-3m) and optimized lattice constants are in good agreement with the previous data. Our GGA+PBE results reveal that MGeBr3 show nonmagnetic semiconductor behavior with direct bandgap (Eg = 0.925 eV (M = Rb), 0.898 eV (M = Cs), 0.952 eV (M = Fr)) along the L–L symmetry direction. Formation energy, octahedral ration and tolerance factor for MGeBr3 have also been calculated. The 2-D charge densities confirm that the chemical bonds (Ge2+–Br- ) and (M+–Br- ) follow the covalent and ionic bonding types. Moreover, we have calculated and discussed the optical parameters, dielectric constants, absorption, conductivity and refractivity. The calculated electronic and optical properties show the narrow band-gap, high absorption and semiconductor nature making these inorganic materials suitable for optoelectronics applications.","PeriodicalId":11233,"journal":{"name":"Digest Journal of Nanomaterials and Biostructures","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140522953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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