Pub Date : 2023-08-29DOI: 10.1080/21870764.2023.2251243
Y. Hayashi, Tatsuya Shishido, Kento Seki, H. Takizawa
ABSTRACT A barium titanium oxide/silver (BaTiO3/Ag) nanocomposite powder was synthesized using a sonochemical process. By irradiating an ethanol solution of BaTiO3 and silver oxide (Ag2O), Ag2O thermally decomposed at 40°C and Ag-loaded BaTiO3 nanocomposites powder was obtained. Nanocomposites containing 30 vol% Ag sintered at 1000°C showed near densities and higher dielectric constants compared to those of BaTiO3 sintered at 1300°C. Moreover, percolation did not occur because the Ag nanoparticles were uniformly dispersed and loaded onto the surface of BaTiO3. This sonochemical method is expected to be a new process for obtaining uniformly dispersed and loaded nanocomposite powders without percolation, even in large amounts.
{"title":"Synthesis of BaTiO3/Ag nanocomposites using a sonochemical process and low-temperature sintering","authors":"Y. Hayashi, Tatsuya Shishido, Kento Seki, H. Takizawa","doi":"10.1080/21870764.2023.2251243","DOIUrl":"https://doi.org/10.1080/21870764.2023.2251243","url":null,"abstract":"ABSTRACT A barium titanium oxide/silver (BaTiO3/Ag) nanocomposite powder was synthesized using a sonochemical process. By irradiating an ethanol solution of BaTiO3 and silver oxide (Ag2O), Ag2O thermally decomposed at 40°C and Ag-loaded BaTiO3 nanocomposites powder was obtained. Nanocomposites containing 30 vol% Ag sintered at 1000°C showed near densities and higher dielectric constants compared to those of BaTiO3 sintered at 1300°C. Moreover, percolation did not occur because the Ag nanoparticles were uniformly dispersed and loaded onto the surface of BaTiO3. This sonochemical method is expected to be a new process for obtaining uniformly dispersed and loaded nanocomposite powders without percolation, even in large amounts.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47674868","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 : 2023-08-28DOI: 10.1080/21870764.2023.2251248
D. Maruoka, K. Harada, T. Murakami, E. Kasai
ABSTRACT The objective of this study is to investigate the influence of Na2SO4 molten salt on the self-healing behavior of Ni/Al2O3 for its utilization as the middle pressure ceramic turbine blades of aircraft. Dense 5 vol% Ni/Al2O3 was prepared and cracks were introduced by the Vickers indentations. The samples were heat-treated ranging from 1000°C to 1150°C for 0.5 h to 48 h in air with Na2SO4 molten salt. The crack lengths of samples before/after the heat treatment were measured using scanning electron microscope (SEM) and the crack disappearance rate was calculated. X-ray diffraction (XRD) results show same peaks in the samples heat-treated with and without Na2SO4 molten salt. The crack disappearance rate of sample heat-treated with Na2SO4 molten salt is higher than that without molten salt and increases according to the parabolic manner. The apparent activation energies for crack disappearance are 354 kJ/mol for the sample heat-treated with Na2SO4 molten salt and 390 kJ/mol for that without Na2SO4 molten salt. The bending strength of the sample heat-treated with Na2SO4 molten salt is equivalent to that of the original sample. Ni/Al2O3 composite exhibits excellent corrosion resistance and self-healing function even in coexistence with Na2SO4 molten salt.
{"title":"Influence of Na2SO4 molten salts on the self-healing behavior of Ni/Al2O3 composites","authors":"D. Maruoka, K. Harada, T. Murakami, E. Kasai","doi":"10.1080/21870764.2023.2251248","DOIUrl":"https://doi.org/10.1080/21870764.2023.2251248","url":null,"abstract":"ABSTRACT The objective of this study is to investigate the influence of Na2SO4 molten salt on the self-healing behavior of Ni/Al2O3 for its utilization as the middle pressure ceramic turbine blades of aircraft. Dense 5 vol% Ni/Al2O3 was prepared and cracks were introduced by the Vickers indentations. The samples were heat-treated ranging from 1000°C to 1150°C for 0.5 h to 48 h in air with Na2SO4 molten salt. The crack lengths of samples before/after the heat treatment were measured using scanning electron microscope (SEM) and the crack disappearance rate was calculated. X-ray diffraction (XRD) results show same peaks in the samples heat-treated with and without Na2SO4 molten salt. The crack disappearance rate of sample heat-treated with Na2SO4 molten salt is higher than that without molten salt and increases according to the parabolic manner. The apparent activation energies for crack disappearance are 354 kJ/mol for the sample heat-treated with Na2SO4 molten salt and 390 kJ/mol for that without Na2SO4 molten salt. The bending strength of the sample heat-treated with Na2SO4 molten salt is equivalent to that of the original sample. Ni/Al2O3 composite exhibits excellent corrosion resistance and self-healing function even in coexistence with Na2SO4 molten salt.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45190903","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 : 2023-08-28DOI: 10.1080/21870764.2023.2252230
Hiroaki Uchiyama, Yuji Tanaka, Shouta Mizuguchi
ABSTRACT The effect of the heating rate on crystallization and densification of sol–gel-derived TiO2 films has been investigated. The TiO2 gel films were prepared from Ti(OC3H7 i )4 solutions containing alcohols (2-butanol and 2-methoxyethanol), glycols (propylene glycol, diethylene glycol and dipropylene glycol) and chelating agents (acetylacetone and benzoylacetone) as organic additives, followed by heat treatment to 800°C at various heating rates. In the cases without organic additives and with alcohols, anatase films were obtained irrespective of the heating rate, where the refractive indexes of the films were higher for slower heating rate. Conversely, for the films prepared with glycols and chelating agents, rapid heating activated crystallization and densification. In particular, addition of chelating agents led to the formation of rutile films with much higher refractive indexes than those of the anatase films.
{"title":"Effect of the heating rate on crystallization and densification of TiO2 films prepared from alkoxide solutions containing various organic additives","authors":"Hiroaki Uchiyama, Yuji Tanaka, Shouta Mizuguchi","doi":"10.1080/21870764.2023.2252230","DOIUrl":"https://doi.org/10.1080/21870764.2023.2252230","url":null,"abstract":"ABSTRACT The effect of the heating rate on crystallization and densification of sol–gel-derived TiO2 films has been investigated. The TiO2 gel films were prepared from Ti(OC3H7 i )4 solutions containing alcohols (2-butanol and 2-methoxyethanol), glycols (propylene glycol, diethylene glycol and dipropylene glycol) and chelating agents (acetylacetone and benzoylacetone) as organic additives, followed by heat treatment to 800°C at various heating rates. In the cases without organic additives and with alcohols, anatase films were obtained irrespective of the heating rate, where the refractive indexes of the films were higher for slower heating rate. Conversely, for the films prepared with glycols and chelating agents, rapid heating activated crystallization and densification. In particular, addition of chelating agents led to the formation of rutile films with much higher refractive indexes than those of the anatase films.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45662757","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 : 2023-08-28DOI: 10.1080/21870764.2023.2248714
Sawao Honda, Yuki Ogihara, A. Ikesue, Y. Aung, Shinobu Hashomoto, Y. Iwamoto
ABSTRACT The microstructure and mechanical properties of polycrystalline spinel ceramics (MgAl2O4) with high translucency were investigated. Several kinds of polycrystalline spinel ceramics were prepared under various sintering conditions, and single-crystal spinel and sapphire were used for comparison. The bending strength of polycrystalline spinel with smaller grain size fabricated without sintering aids exceeded that of single-crystal spinel. The bending strength at 1000°C tended to be lower than that at room temperature. The fracture toughness of polycrystalline spinel prepared without sintering aids measured by SEVNB was higher than that of spinel with sintering aids. By estimation of fracture strength considering different fracture origins, the polycrystalline spinel prepared without sintering aids might be fractured mainly from defects around residual spherical voids. If the size of voids can be minimized in polycrystalline spinel fabricated without sintering aids, both high transmission and good mechanical properties could be achieved.
{"title":"Optical and mechanical properties characterizations of transparent polycrystalline MgAl2O4 spinel","authors":"Sawao Honda, Yuki Ogihara, A. Ikesue, Y. Aung, Shinobu Hashomoto, Y. Iwamoto","doi":"10.1080/21870764.2023.2248714","DOIUrl":"https://doi.org/10.1080/21870764.2023.2248714","url":null,"abstract":"ABSTRACT The microstructure and mechanical properties of polycrystalline spinel ceramics (MgAl2O4) with high translucency were investigated. Several kinds of polycrystalline spinel ceramics were prepared under various sintering conditions, and single-crystal spinel and sapphire were used for comparison. The bending strength of polycrystalline spinel with smaller grain size fabricated without sintering aids exceeded that of single-crystal spinel. The bending strength at 1000°C tended to be lower than that at room temperature. The fracture toughness of polycrystalline spinel prepared without sintering aids measured by SEVNB was higher than that of spinel with sintering aids. By estimation of fracture strength considering different fracture origins, the polycrystalline spinel prepared without sintering aids might be fractured mainly from defects around residual spherical voids. If the size of voids can be minimized in polycrystalline spinel fabricated without sintering aids, both high transmission and good mechanical properties could be achieved.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42997607","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 : 2023-08-17DOI: 10.1080/21870764.2023.2247210
Jishita Ravoor, S. Elsen, Mahendran Thangavel, Dhanabal Arumugam, Deepan Karuppan
ABSTRACT Additive manufacturing is a fabrication technique where materials are built up layer-by-layer allowing the realization of complex designs. Ceramic additive manufacturing is steadily increasing in the market and industries are developing 3D printers that are economical and efficient to print single/multi-material. The development of free-form extrusion-type printers has been of great significance due to their wide range of materials used, availability of technology, low development cost, and design freedom in developing the structures. We have successfully developed a hybrid multi-head 3D printer with four print heads capable of operating individually or together to print multiple layers using different materials. The three mechanically actuated print heads are provided to print ceramic, metallic slurry, and polymeric materials, and one pneumatic actuated print head is for printing bio-ink. The developed hybrid multi-head 3D printer can be beneficial in printing a wide range of materials such as metals, ceramics, polymers, and composites due to its flexibility in printing materials of different viscosities at different pressure. The optimization of the printing of calcium silicate bio-ceramics and multi-material is also studied and reported.
{"title":"Development of hybrid multi-head, multi-material paste and ink extrusion type 3D printer for biomedical applications","authors":"Jishita Ravoor, S. Elsen, Mahendran Thangavel, Dhanabal Arumugam, Deepan Karuppan","doi":"10.1080/21870764.2023.2247210","DOIUrl":"https://doi.org/10.1080/21870764.2023.2247210","url":null,"abstract":"ABSTRACT Additive manufacturing is a fabrication technique where materials are built up layer-by-layer allowing the realization of complex designs. Ceramic additive manufacturing is steadily increasing in the market and industries are developing 3D printers that are economical and efficient to print single/multi-material. The development of free-form extrusion-type printers has been of great significance due to their wide range of materials used, availability of technology, low development cost, and design freedom in developing the structures. We have successfully developed a hybrid multi-head 3D printer with four print heads capable of operating individually or together to print multiple layers using different materials. The three mechanically actuated print heads are provided to print ceramic, metallic slurry, and polymeric materials, and one pneumatic actuated print head is for printing bio-ink. The developed hybrid multi-head 3D printer can be beneficial in printing a wide range of materials such as metals, ceramics, polymers, and composites due to its flexibility in printing materials of different viscosities at different pressure. The optimization of the printing of calcium silicate bio-ceramics and multi-material is also studied and reported.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44997460","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}
ABSTRACT Using a continuous laser to soften glass locally is a novel way of selective glass forming. Due to gaussian distribution of laser power density, a temperature gradient will be generated on glass treated with localized irradiation by laser, which brings about the coexistence of a glass state and a viscoelastic state. This situation creates a bulge on the surface of the softened area. Based on this phenomenon, we propose a measurement approach and a calculation model for the softening zone width of glass irradiated locally by laser and verify the calculation model through simulations and experiments. The maximum temperature deviation of the proposed temperature field prediction model is 4.7°C, while the minimum deviation is 0.53°C; making the deviation between the calculation model of the softening zone width and the experimental measurement result less than 0.319%.
{"title":"Melt pool size of optical glass irradiated by semiconductor laser","authors":"Weijie Fu, Lianshuang Ning, X. Zhou, Xinming Zhang","doi":"10.1080/21870764.2023.2236449","DOIUrl":"https://doi.org/10.1080/21870764.2023.2236449","url":null,"abstract":"ABSTRACT Using a continuous laser to soften glass locally is a novel way of selective glass forming. Due to gaussian distribution of laser power density, a temperature gradient will be generated on glass treated with localized irradiation by laser, which brings about the coexistence of a glass state and a viscoelastic state. This situation creates a bulge on the surface of the softened area. Based on this phenomenon, we propose a measurement approach and a calculation model for the softening zone width of glass irradiated locally by laser and verify the calculation model through simulations and experiments. The maximum temperature deviation of the proposed temperature field prediction model is 4.7°C, while the minimum deviation is 0.53°C; making the deviation between the calculation model of the softening zone width and the experimental measurement result less than 0.319%.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47326788","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 : 2023-07-03DOI: 10.1080/21870764.2023.2245610
Lav Kush, S. Srivastava, S. Vajpai, S. Savilov
ABSTRACT The thermoelectric properties of a new type of Pr2-xSrxFeCrO6 double perovskite were investigated at higher temperature after its sol-gel synthesis. The XRD results validate the single-phase orthorhombic structure, and the crystallite sizes meet the morphological measurements. XPS examination, which formed the defect sites in these oxides, confirmed the varied oxidation states of constituents. The temperature-dependent electrical conductivity (σ) was poor in the original Pr2FeCrO6 composition, but after substituting Sr on the Pr-site, a significant rise in σ with two semiconductors and one metal transition was observed. A positive Seebeck coefficient confirmed the presence of a p-type charge carrier in the entire composition, and the charge transport mechanism was driven by the SPH model. Thermal conductivity increases in all doped samples, while it decreases in pristine compounds over the broad analyzed temperature range. Thermal expansion coefficient increased after doping in oxygen-deficient compound. The PrSrFeCrO6 compound had the maximum ZT (0.105), which was 3.9 times higher than that of the pristine compound.
{"title":"Effect of Sr-doping on electronic and thermal properties of Pr2-xSrxFeCrO6 (0≤x≤1) oxide materials synthesized by using sol-gel technique","authors":"Lav Kush, S. Srivastava, S. Vajpai, S. Savilov","doi":"10.1080/21870764.2023.2245610","DOIUrl":"https://doi.org/10.1080/21870764.2023.2245610","url":null,"abstract":"ABSTRACT The thermoelectric properties of a new type of Pr2-xSrxFeCrO6 double perovskite were investigated at higher temperature after its sol-gel synthesis. The XRD results validate the single-phase orthorhombic structure, and the crystallite sizes meet the morphological measurements. XPS examination, which formed the defect sites in these oxides, confirmed the varied oxidation states of constituents. The temperature-dependent electrical conductivity (σ) was poor in the original Pr2FeCrO6 composition, but after substituting Sr on the Pr-site, a significant rise in σ with two semiconductors and one metal transition was observed. A positive Seebeck coefficient confirmed the presence of a p-type charge carrier in the entire composition, and the charge transport mechanism was driven by the SPH model. Thermal conductivity increases in all doped samples, while it decreases in pristine compounds over the broad analyzed temperature range. Thermal expansion coefficient increased after doping in oxygen-deficient compound. The PrSrFeCrO6 compound had the maximum ZT (0.105), which was 3.9 times higher than that of the pristine compound.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42956945","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 : 2023-07-03DOI: 10.1080/21870764.2023.2237358
R. Ali, Qadeer Akbar Sial, Young Jae Lee, Muhammad Waqas, S. Kalanur, H. Seo
ABSTRACT Photoelectrochemical (PEC) water splitting is one of the most sustainable approaches for converting solar energy into hydrogen fuel. Affordable and robust photoelectrodes are crucial for the commercialization of PEC technologies. Recently, transition metal-based co-catalysts, especially Ni- and Fe-based catalysts, have attracted much interest owing to their exceptional OER characteristics. Given this, we here proposed the decoration of a Fe-Ni-based cocatalyst on the surface of the TiO2 photoanode for PEC water splitting. The TiO2 photoanode was hydrothermally synthesized and then decorated by Fe-Ni hydroxide catalyst using photo-assisted electrodeposition. The optimized TiO2/FeNiOOH photoanode exhibited the maximum photocurrent density value of 1.36 mA cm−2, which is almost twice the value obtained for bare TiO2, at 1.23 V vs RHE under the AM 1.5 G illumination. Due to the enhanced light absorption in the UV region, the optimized photoanode exhibited remarkable IPCE and photoconversion efficiency of 87.8% and 0.93%, respectively. Furthermore, excellent faradaic efficiencies of ∼90% for H2 and ∼70% for O2 generations were obtained. Predominantly, the enhancement in the photocurrent potentials was explained in detail. Our study shows the roles and benefits of using bimetallic catalysts with TiO2 photoanodes for sustainable water-splitting applications.
光电化学(PEC)水分解是将太阳能转化为氢燃料的最可持续的方法之一。价格合理且坚固耐用的光电极对于PEC技术的商业化至关重要。近年来，过渡金属基催化剂，特别是镍基和铁基催化剂，由于其特殊的OER特性而引起了人们的广泛关注。鉴于此，我们提出在TiO2光阳极表面装饰fe - ni基助催化剂用于PEC水分解。采用水热法合成了TiO2光阳极，并用Fe-Ni氢氧化物催化剂进行光辅助电沉积修饰。优化后的TiO2/FeNiOOH光阳极在AM 1.5 G光照下，在1.23 V vs RHE下的最大光电流密度值为1.36 mA cm−2，几乎是裸TiO2光电流密度的两倍。由于增强了紫外区的光吸收，优化后的光阳极的IPCE和光转换效率分别达到87.8%和0.93%。此外，H2代的法拉第效率为~ 90%，O2代的法拉第效率为~ 70%。主要是对光电流势的增强作了详细的解释。我们的研究显示了使用双金属催化剂和TiO2光阳极在可持续水分解应用中的作用和好处。
{"title":"A Synergic Effect of Bi-metallic Layered Hydro-Oxide Cocatalyst on 1-D TiO2 Driven Photoelectrochemical Water Splitting","authors":"R. Ali, Qadeer Akbar Sial, Young Jae Lee, Muhammad Waqas, S. Kalanur, H. Seo","doi":"10.1080/21870764.2023.2237358","DOIUrl":"https://doi.org/10.1080/21870764.2023.2237358","url":null,"abstract":"ABSTRACT Photoelectrochemical (PEC) water splitting is one of the most sustainable approaches for converting solar energy into hydrogen fuel. Affordable and robust photoelectrodes are crucial for the commercialization of PEC technologies. Recently, transition metal-based co-catalysts, especially Ni- and Fe-based catalysts, have attracted much interest owing to their exceptional OER characteristics. Given this, we here proposed the decoration of a Fe-Ni-based cocatalyst on the surface of the TiO2 photoanode for PEC water splitting. The TiO2 photoanode was hydrothermally synthesized and then decorated by Fe-Ni hydroxide catalyst using photo-assisted electrodeposition. The optimized TiO2/FeNiOOH photoanode exhibited the maximum photocurrent density value of 1.36 mA cm−2, which is almost twice the value obtained for bare TiO2, at 1.23 V vs RHE under the AM 1.5 G illumination. Due to the enhanced light absorption in the UV region, the optimized photoanode exhibited remarkable IPCE and photoconversion efficiency of 87.8% and 0.93%, respectively. Furthermore, excellent faradaic efficiencies of ∼90% for H2 and ∼70% for O2 generations were obtained. Predominantly, the enhancement in the photocurrent potentials was explained in detail. Our study shows the roles and benefits of using bimetallic catalysts with TiO2 photoanodes for sustainable water-splitting applications.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46457266","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 : 2023-07-03DOI: 10.1080/21870764.2023.2236441
Noboru Yamaguchi, Ryosuke Nakazato, Keeko Matsumoto, Masako Kakesu, N. Rosero-Navarro, A. Miura, K. Tadanaga
ABSTRACT Electrocatalytic CO2 reduction reaction (CO2RR) has attracted considerable attention as a technology to recycle carbon dioxide (CO2) into raw materials for chemicals using renewable energies. In this study, the electrocatalytic CO2RR activity of Zn-Al layered double hydroxides (LDHs) was studied. Zn-Al LDHs loaded carbon sheets were prepared, and CO2 RR was performed using CO2-saturated KHCO3 electrolyte to confirm the catalytic ability of Zn-Al LDH. Zn-Al LDHs intercalated with CO3 2− anion were synthesized using the mixture of metal nitrates with the different molar ratio of Zn2+/Al3+ by the co-precipitation process, whose corresponding products were named as Zn2Al1 LDH, Zn3Al1 LDH, and Zn4Al1 LDH, respectively. Except for Zn2Al1 LDH, ZnO was observed to exist as an impurity. The synthesized Zn-Al LDHs exhibited the electrocatalytic CO2RR activity for CO formation. In the case of the Zn2Al1 LDH, the current density of 15 mA cm−2 was obtained with 77% selectivity for CO and 94% selectivity for (CO + H2) at − 1.4 V vs. RHE. Furthermore, Zn3Al1 and Zn4Al1 LDHs showed a significant change relating to ZnO impurities in the XRD patterns and SEM images before and after the CO2RR whereas Zn2Al1 LDH did not show it. These results indicate that Zn-Al LDH is promising as a CO2RR electrocatalyst for CO formation.
{"title":"Electrocatalytic property of Zn-Al layered double hydroxides for CO2 electrochemical reduction","authors":"Noboru Yamaguchi, Ryosuke Nakazato, Keeko Matsumoto, Masako Kakesu, N. Rosero-Navarro, A. Miura, K. Tadanaga","doi":"10.1080/21870764.2023.2236441","DOIUrl":"https://doi.org/10.1080/21870764.2023.2236441","url":null,"abstract":"ABSTRACT Electrocatalytic CO2 reduction reaction (CO2RR) has attracted considerable attention as a technology to recycle carbon dioxide (CO2) into raw materials for chemicals using renewable energies. In this study, the electrocatalytic CO2RR activity of Zn-Al layered double hydroxides (LDHs) was studied. Zn-Al LDHs loaded carbon sheets were prepared, and CO2 RR was performed using CO2-saturated KHCO3 electrolyte to confirm the catalytic ability of Zn-Al LDH. Zn-Al LDHs intercalated with CO3 2− anion were synthesized using the mixture of metal nitrates with the different molar ratio of Zn2+/Al3+ by the co-precipitation process, whose corresponding products were named as Zn2Al1 LDH, Zn3Al1 LDH, and Zn4Al1 LDH, respectively. Except for Zn2Al1 LDH, ZnO was observed to exist as an impurity. The synthesized Zn-Al LDHs exhibited the electrocatalytic CO2RR activity for CO formation. In the case of the Zn2Al1 LDH, the current density of 15 mA cm−2 was obtained with 77% selectivity for CO and 94% selectivity for (CO + H2) at − 1.4 V vs. RHE. Furthermore, Zn3Al1 and Zn4Al1 LDHs showed a significant change relating to ZnO impurities in the XRD patterns and SEM images before and after the CO2RR whereas Zn2Al1 LDH did not show it. These results indicate that Zn-Al LDH is promising as a CO2RR electrocatalyst for CO formation.","PeriodicalId":15130,"journal":{"name":"Journal of Asian Ceramic Societies","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46103938","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 : 2023-06-29DOI: 10.1080/21870764.2023.2227535
C. Corlett, N. Obradović, J. Watts, E. Bohannan, W. Fahrenholtz
ABSTRACT The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co0.2Cu0.2Mg0.2Ni0.2 Zn0.2)Al2O4. Each composition was reacted to form a single phase, but analysis of X-ray diffraction patterns revealed differences in cation site occupancy with the high-entropy spinel being nearly fully normal. Densification behavior was investigated and showed that fully dense ceramics could be produced by hot pressing at temperatures as low as 1375°C for all compositions. Vickers’ hardness values were at least 10 GPa for all compositions. The cations present in the high-entropy spinel appear to have a stabilizing effect that led to nearly normal site occupancy compared to full cation inversion behavior of nickel aluminate spinel. This is the first report that compares cation site occupancy of a high-entropy spinel to conventional spinel ceramics.
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