Toluene is one of the volatile organic compounds which are harmful to the environment and human health. One promising approach to eliminate toluene is catalytic combustion. Although precious metal based catalysts are known to show high activity for toluene combustion, the high price of the precious metals has restricted their widespread applications. In this study, precious-metal-free catalysts of Co3O4/ZrSn1−xFexO4−δ were synthesized for toluene combustion. Here, scrutinyite-type ZrSnO4 was focused as a promoter which can supply active oxygen species from inside the lattice toward the Co3O4 activator. In addition, Fe2+/3+ ions were introduced into the ZrSnO4 lattice to enhance the oxygen supply ability owing to the improvement of redox properties and the formation of oxygen vacancies for smooth oxide ion migration. The oxygen supply from the ZrSn1−xFexO4−δ lattice facilitated toluene oxidation on Co3O4, and the highest catalytic activity was obtained for the 19 wt% Co3O4/ZrSn0.93Fe0.07O4−δ (Co3O4/ZSF0.07) catalyst, where the complete combustion was realized at the temperature as low as 250 °C. The toluene combustion reaction over Co3O4/ZSF0.07 is considered to proceed along a typical route of the rapid transformation of toluene into the intermediates (benzyl alcohol, benzaldehyde, benzoate, and maleic anhydride) and finally the formation of carbon dioxide and water.
{"title":"Catalytic Combustion of Toluene over Co3O4 loaded on ZrSn1−xFexO4−δ","authors":"Naoyoshi Nunotani, Takumi Tanaka, Nobuhito Imanaka","doi":"10.1093/bulcsj/uoae084","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae084","url":null,"abstract":"Toluene is one of the volatile organic compounds which are harmful to the environment and human health. One promising approach to eliminate toluene is catalytic combustion. Although precious metal based catalysts are known to show high activity for toluene combustion, the high price of the precious metals has restricted their widespread applications. In this study, precious-metal-free catalysts of Co3O4/ZrSn1−xFexO4−δ were synthesized for toluene combustion. Here, scrutinyite-type ZrSnO4 was focused as a promoter which can supply active oxygen species from inside the lattice toward the Co3O4 activator. In addition, Fe2+/3+ ions were introduced into the ZrSnO4 lattice to enhance the oxygen supply ability owing to the improvement of redox properties and the formation of oxygen vacancies for smooth oxide ion migration. The oxygen supply from the ZrSn1−xFexO4−δ lattice facilitated toluene oxidation on Co3O4, and the highest catalytic activity was obtained for the 19 wt% Co3O4/ZrSn0.93Fe0.07O4−δ (Co3O4/ZSF0.07) catalyst, where the complete combustion was realized at the temperature as low as 250 °C. The toluene combustion reaction over Co3O4/ZSF0.07 is considered to proceed along a typical route of the rapid transformation of toluene into the intermediates (benzyl alcohol, benzaldehyde, benzoate, and maleic anhydride) and finally the formation of carbon dioxide and water.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141773358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zannatul Mumtarin Moushumy, Hiroshi Yoshida, Kaori Tokusada, Ai Kuraoka, Sota Sakamoto, Masayuki Tsushida, Masato Machida
The surface grafting of NiO onto CeO2 nanocrystallites generates heterointerface structures, providing efficient active sites for CO–NO reactions toward forming N2 and CO2. In this study, we investigated the effects of high-temperature thermal aging on the activity and nanostructure of the NiO/CeO2 catalyst. After thermal aging at 900 °C, the catalyst retained a high catalytic activity, whereas the reference catalysts lost theirs owing to considerable solid-state reactions and sintering. The as-prepared fresh NiO/CeO2 catalyst (calcined at 600 °C) contained high dispersions of NiO species in CeO2 crystallites. Conversely, the thermally aged catalyst comprised grown NiO and CeO2 crystallites were allowed to contact intimately to form thermostable interfaces, where the perimeter in the vicinity provided the Ni2+-incorporated CeO2 surface for removing and filling the oxygen species in the catalytic cycle toward facilitating CO–NO reactions. Based on in situ Fourier transform infrared and parallel isotopic reaction analyses, we confirmed the following as possible pathways: (i) the removal of the surface oxygen by the adsorbed CO to form an oxygen vacancy (VO), (ii) the interaction between the adsorbed NO with VO, and (iii) the N–O bond cleavage and the reaction with CO to form isocyanate, followed by the reaction with NO to produce N2.
NiO 表面接枝到 CeO2 纳米晶上会产生异质界面结构，为 CO-NO 反应生成 N2 和 CO2 提供有效的活性位点。在本研究中，我们研究了高温热老化对 NiO/CeO2 催化剂活性和纳米结构的影响。在 900 °C 高温老化后，催化剂保持了较高的催化活性，而参考催化剂则由于大量固态反应和烧结而丧失了催化活性。新制备的 NiO/CeO2 催化剂（600 ℃ 煅烧）在 CeO2 晶粒中含有大量分散的 NiO 物种。相反，经过热老化的催化剂由生长的 NiO 和 CeO2 结晶体组成，它们紧密接触形成热稳定性界面，附近的周边提供了 Ni2+ 并入的 CeO2 表面，用于去除和填充催化循环中的氧物种，从而促进 CO-NO 反应。根据原位傅立叶变换红外分析和平行同位素反应分析，我们确认了以下可能的途径：(i) 吸附的 CO 清除表面氧，形成氧空位 (VO)；(ii) 吸附的 NO 与 VO 相互作用；(iii) N-O 键裂解，与 CO 反应生成异氰酸酯，然后与 NO 反应生成 N2。
{"title":"The activity of thermostable NiO/CeO2 heterointerface structure toward low-temperature catalytic CO–NO reaction","authors":"Zannatul Mumtarin Moushumy, Hiroshi Yoshida, Kaori Tokusada, Ai Kuraoka, Sota Sakamoto, Masayuki Tsushida, Masato Machida","doi":"10.1093/bulcsj/uoae081","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae081","url":null,"abstract":"The surface grafting of NiO onto CeO2 nanocrystallites generates heterointerface structures, providing efficient active sites for CO–NO reactions toward forming N2 and CO2. In this study, we investigated the effects of high-temperature thermal aging on the activity and nanostructure of the NiO/CeO2 catalyst. After thermal aging at 900 °C, the catalyst retained a high catalytic activity, whereas the reference catalysts lost theirs owing to considerable solid-state reactions and sintering. The as-prepared fresh NiO/CeO2 catalyst (calcined at 600 °C) contained high dispersions of NiO species in CeO2 crystallites. Conversely, the thermally aged catalyst comprised grown NiO and CeO2 crystallites were allowed to contact intimately to form thermostable interfaces, where the perimeter in the vicinity provided the Ni2+-incorporated CeO2 surface for removing and filling the oxygen species in the catalytic cycle toward facilitating CO–NO reactions. Based on in situ Fourier transform infrared and parallel isotopic reaction analyses, we confirmed the following as possible pathways: (i) the removal of the surface oxygen by the adsorbed CO to form an oxygen vacancy (VO), (ii) the interaction between the adsorbed NO with VO, and (iii) the N–O bond cleavage and the reaction with CO to form isocyanate, followed by the reaction with NO to produce N2.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141773355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The covalent functionalization of black phosphorus quantum dots (BPQDs) with organic species or polymers will inevitably change or damage their electronic structure and intrinsic structure. To address this problem and explore application of BPQDs in transient digital-type memristors, a polydopamine (PDA) thin film is first synthesized in situ on the surface of BPQDs to produce a donor–acceptor type BPQDs@PDA composite which is directly used to react with 2-bromoisobutyryl bromide to give BPQDs@PDA-Br. By using BPQDs@PDA-Br as atom transfer radical polymerization agent, a large number of polyvinylspiropyran chains (PSP) are in situ grown from the PDA surface to yield BPQDs@PDA-PSP. Upon UV/visible light illumination, the spiropyran’s two isomers (ring-closed spiropyran form and ring-opened merocyanine) in the PSP moieties will interconvert into each other rapidly. As expected, the as-fabricated ITO/BPQDs@PDA-PSP/ITO device exhibits typical nonvolatile digital-type memristive performance under visible irradiation, with a small turn-on voltage of -1.52 V, a turn-off voltage of +1.16 V, and an ON/OFF ratio of with an ON/OFF current ratio of 1.02 ×104. Upon UV illumination, the information stored in the device is quickly and completely erased within six seconds. By utilizing a simple memristor-based convolutional neural network, one can easily realize handwritten digit recognition. After 10 epochs of training, numeral recognition accuracy can reach up to 96.21%.
{"title":"Black Phosphorus Quantum Dots Functionalized with Photochromic Poly(vinylspiropyran)-Grafted Polydopamine for Transient Digital-Type Memristors","authors":"Zemiao Zhao, Qiang Che, Qian Chen, Kexin Wang, Kejia Zhao, Chenjian Zhang, Haidong He, Xinzhu Wang, Yu Chen","doi":"10.1093/bulcsj/uoae083","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae083","url":null,"abstract":"The covalent functionalization of black phosphorus quantum dots (BPQDs) with organic species or polymers will inevitably change or damage their electronic structure and intrinsic structure. To address this problem and explore application of BPQDs in transient digital-type memristors, a polydopamine (PDA) thin film is first synthesized in situ on the surface of BPQDs to produce a donor–acceptor type BPQDs@PDA composite which is directly used to react with 2-bromoisobutyryl bromide to give BPQDs@PDA-Br. By using BPQDs@PDA-Br as atom transfer radical polymerization agent, a large number of polyvinylspiropyran chains (PSP) are in situ grown from the PDA surface to yield BPQDs@PDA-PSP. Upon UV/visible light illumination, the spiropyran’s two isomers (ring-closed spiropyran form and ring-opened merocyanine) in the PSP moieties will interconvert into each other rapidly. As expected, the as-fabricated ITO/BPQDs@PDA-PSP/ITO device exhibits typical nonvolatile digital-type memristive performance under visible irradiation, with a small turn-on voltage of -1.52 V, a turn-off voltage of +1.16 V, and an ON/OFF ratio of with an ON/OFF current ratio of 1.02 ×104. Upon UV illumination, the information stored in the device is quickly and completely erased within six seconds. By utilizing a simple memristor-based convolutional neural network, one can easily realize handwritten digit recognition. After 10 epochs of training, numeral recognition accuracy can reach up to 96.21%.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Capacitive deionization (CDI) is an efficient and cost-effective technology for ion removal from brackish water. Here, we demonstrate a sulfonate-functionalized covalent organic framework (COF) as a novel faradaic cathode material for CDI applications. Due to its orderly arranged adsorption units in the COF, the resulting COF demonstrate a superior sodium cations removal capacity of 19.56 mg g−1 and a maximum desalination rate of 3.15 mg g-1 s−1 in a 500 ppm NaCl solution.
{"title":"Sulfonate-Functionalized Covalent Organic Frameworks for Capacitive Deionization","authors":"Dong Jiang, Xingtao Xu, Yoshio Bando, Saad M Alshehri, Miharu Eguchi, Toru Asahi, Yusuke Yamauchi","doi":"10.1093/bulcsj/uoae074","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae074","url":null,"abstract":"Capacitive deionization (CDI) is an efficient and cost-effective technology for ion removal from brackish water. Here, we demonstrate a sulfonate-functionalized covalent organic framework (COF) as a novel faradaic cathode material for CDI applications. Due to its orderly arranged adsorption units in the COF, the resulting COF demonstrate a superior sodium cations removal capacity of 19.56 mg g−1 and a maximum desalination rate of 3.15 mg g-1 s−1 in a 500 ppm NaCl solution.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Moriaki Sakihara, Shuhei Shimoyama, Miki B Kurosawa, Junichiro Yamaguchi
In this study, we developed a method to synthesize deoxygenative functionalized products by reacting aromatic dicarbonyls with DBU, TMSOTf, diphenylphosphine oxide, and a range of nucleophiles. Moreover, we demonstrated that sequential application of phospha-Brook rearrangement and benzylic substitution conditions to aromatic aldehydes affords the deoxygenative functionalized products effectively. With highly nucleophilic reagents, it was possible to proceed with the deoxygenative functionalization without TMSOTf.
{"title":"Deoxygenative Functionalizations of Aromatic Dicarbonyls and Aldehydes","authors":"Moriaki Sakihara, Shuhei Shimoyama, Miki B Kurosawa, Junichiro Yamaguchi","doi":"10.1093/bulcsj/uoae078","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae078","url":null,"abstract":"In this study, we developed a method to synthesize deoxygenative functionalized products by reacting aromatic dicarbonyls with DBU, TMSOTf, diphenylphosphine oxide, and a range of nucleophiles. Moreover, we demonstrated that sequential application of phospha-Brook rearrangement and benzylic substitution conditions to aromatic aldehydes affords the deoxygenative functionalized products effectively. With highly nucleophilic reagents, it was possible to proceed with the deoxygenative functionalization without TMSOTf.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent advances in chain-growth reversible deactivation radical polymerization (CG-RDRP), i.e. the so-called “living radical polymerization”, have synergistically developed step-growth radical polymerizations via controlled formation of radical species from covalent bonds followed by irreversible deactivation of the resulting radical species. The monomers for radical polyaddition are thus designed to possess carbon–halogen or thioester bonds, which can generate radical species in the presence of transition metal catalysts and radical initiators, as well as carbon‒carbon double bonds, which will irreversibly form carbon–halogen or thioester bonds. Radical polycondensations are achievable via radical coupling reactions of carbon-centered radicals generated from carbon–halogen bonds or radical quenching reactions with nitroxides. Furthermore, radical addition-condensation polymerizations are achieved by a sequence of reactions, i.e. the formation of radical species from carbon–halogen bonds, radical addition to nitroso or thiocarbonylthio compounds, and coupling or quenching reactions with the resulting stable radical. These step-growth irreversible deactivation radical polymerizations (SG-IDRP) enable the synthesis of a variety of polymers, such as polyethers, polyesters, polyamides, and polyimides, which have aliphatic, aromatic, polar, and degradable groups in their main chains. Sequence-regulated vinyl polymer structures can also be constructed by designing monomers. Combinations with CG-RDRPs further lead to unique hybrid block, multiblock, graft, hyperbranched, and network polymers.
{"title":"Step-growth irreversible deactivation radical polymerization: synergistic developments with chain-growth reversible deactivation radical polymerization","authors":"Masami Kamigaito","doi":"10.1093/bulcsj/uoae069","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae069","url":null,"abstract":"Recent advances in chain-growth reversible deactivation radical polymerization (CG-RDRP), i.e. the so-called “living radical polymerization”, have synergistically developed step-growth radical polymerizations via controlled formation of radical species from covalent bonds followed by irreversible deactivation of the resulting radical species. The monomers for radical polyaddition are thus designed to possess carbon–halogen or thioester bonds, which can generate radical species in the presence of transition metal catalysts and radical initiators, as well as carbon‒carbon double bonds, which will irreversibly form carbon–halogen or thioester bonds. Radical polycondensations are achievable via radical coupling reactions of carbon-centered radicals generated from carbon–halogen bonds or radical quenching reactions with nitroxides. Furthermore, radical addition-condensation polymerizations are achieved by a sequence of reactions, i.e. the formation of radical species from carbon–halogen bonds, radical addition to nitroso or thiocarbonylthio compounds, and coupling or quenching reactions with the resulting stable radical. These step-growth irreversible deactivation radical polymerizations (SG-IDRP) enable the synthesis of a variety of polymers, such as polyethers, polyesters, polyamides, and polyimides, which have aliphatic, aromatic, polar, and degradable groups in their main chains. Sequence-regulated vinyl polymer structures can also be constructed by designing monomers. Combinations with CG-RDRPs further lead to unique hybrid block, multiblock, graft, hyperbranched, and network polymers.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chemical phenomena are inherently complex and stochastic, making them difficult to fully understand using conventional ensemble-averaged analytical methods. These methods primarily capture long-lived species and common structural features, limiting the study of transient intermediates and minute structural characteristics. In contrast, single-molecule time-resolved analysis using advanced microscopy techniques, particularly transmission electron microscopy (TEM), offers high spatial and temporal resolution to observe the nonequilibrium dynamics of molecules and their assemblies. This account discusses the authors’ research on developing TEM techniques to visualize intricate and transient interactions within molecular systems, enhancing the understanding of chemical phenomena at atomic and molecular levels.
化学现象本身具有复杂性和随机性，因此难以用传统的集合平均分析方法完全理解。这些方法主要捕捉长寿命物种和常见结构特征，限制了对瞬时中间产物和微小结构特征的研究。相比之下，利用先进的显微镜技术，特别是透射电子显微镜（TEM）进行单分子时间分辨分析，可提供高空间和时间分辨率，观察分子及其组装体的非平衡动态。这篇文章讨论了作者在开发 TEM 技术方面的研究，这些技术可将分子系统内错综复杂的瞬时相互作用可视化，从而加深对原子和分子水平化学现象的理解。
{"title":"High-Speed Imaging and Quantitative Analysis of Non-Equilibrium Stochastic Processes Using Atomic-Resolution Electron Microscopy","authors":"Takayuki Nakamuro","doi":"10.1093/bulcsj/uoae082","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae082","url":null,"abstract":"\u0000 Chemical phenomena are inherently complex and stochastic, making them difficult to fully understand using conventional ensemble-averaged analytical methods. These methods primarily capture long-lived species and common structural features, limiting the study of transient intermediates and minute structural characteristics. In contrast, single-molecule time-resolved analysis using advanced microscopy techniques, particularly transmission electron microscopy (TEM), offers high spatial and temporal resolution to observe the nonequilibrium dynamics of molecules and their assemblies. This account discusses the authors’ research on developing TEM techniques to visualize intricate and transient interactions within molecular systems, enhancing the understanding of chemical phenomena at atomic and molecular levels.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141640474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafat Tahawy, Mohamed Esmat, Hamza El-Hosainy, Fatma E Farghaly, El-Sayed A Abdel-Aal, F I El-Hosiny, Yusuke Ide
Research into TiO2 photocatalysts for solar H2 evolution from water is still growing for environmentally benign and economically valid H2 production. Herein, in contrast to many researches on the modification of TiO2 toward higher photocatalytic activities, we develop a photocatalytically inactive TiO2-based nanostructure and use it, like graphene, as a booster of a benchmark TiO2. A layered potassium titanate with two-dimensional plate-like particle morphology was converted to the corresponding one-dimensional nanowire form via a hydrothermal reaction, after which the layered potassium titanate nanowire was acid-treated to obtain a layered titanate nanowire. This nanowire was completely inactive toward H2 evolution from water containing methanol under solar simulator irradiation. However, when Pt nanoparticle-loaded P25 TiO2 (Pt/P25) was mixed with a considerably smaller amount of the layered titanate nanowire in water, a durable composite was obtained and the composite showed a good photocatalytic activity three times higher than Pt/P25. The apparent quantum efficiency of the reaction at wavelength of 350 nm was 56%, which was higher than or comparable to those of the state-of-the-art TiO2-based photocatalysts. The possible reason for the enhanced photocatalytic activity of the Pt/P25 and layered titanate nanowire composite involved the transfer of photogenerated holes from Pt/P25 to the nanowire to suppress charge recombination and/or disaggregation (improved dispersion) of Pt/P25 particles on the nanowire.
{"title":"A Layered Titanate Nanowire Helps Pt/TiO2 Photocatalyst for Solar Hydrogen Evolution from Water with High Quantum Efficiency","authors":"Rafat Tahawy, Mohamed Esmat, Hamza El-Hosainy, Fatma E Farghaly, El-Sayed A Abdel-Aal, F I El-Hosiny, Yusuke Ide","doi":"10.1093/bulcsj/uoae079","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae079","url":null,"abstract":"Research into TiO2 photocatalysts for solar H2 evolution from water is still growing for environmentally benign and economically valid H2 production. Herein, in contrast to many researches on the modification of TiO2 toward higher photocatalytic activities, we develop a photocatalytically inactive TiO2-based nanostructure and use it, like graphene, as a booster of a benchmark TiO2. A layered potassium titanate with two-dimensional plate-like particle morphology was converted to the corresponding one-dimensional nanowire form via a hydrothermal reaction, after which the layered potassium titanate nanowire was acid-treated to obtain a layered titanate nanowire. This nanowire was completely inactive toward H2 evolution from water containing methanol under solar simulator irradiation. However, when Pt nanoparticle-loaded P25 TiO2 (Pt/P25) was mixed with a considerably smaller amount of the layered titanate nanowire in water, a durable composite was obtained and the composite showed a good photocatalytic activity three times higher than Pt/P25. The apparent quantum efficiency of the reaction at wavelength of 350 nm was 56%, which was higher than or comparable to those of the state-of-the-art TiO2-based photocatalysts. The possible reason for the enhanced photocatalytic activity of the Pt/P25 and layered titanate nanowire composite involved the transfer of photogenerated holes from Pt/P25 to the nanowire to suppress charge recombination and/or disaggregation (improved dispersion) of Pt/P25 particles on the nanowire.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141721366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intermolecular interactions in 1:1 inclusion complexes of cucurbit[7]uril (CB[7]) with phenylalanine derivatives were investigated by density functional theory (B97-D) calculations. For each complex, two optimized geometries were found: conformer C in which a guest molecule resided in the center of CB[7], and conformer E where a guest molecule was present at the edge of CB[7]. The order of energy differences between these conformers agreed well with previously reported differences in the affinity of guest molecules for CB[7]. Molecular dynamics simulations of the complexes showed that the guest molecules in CB[7] had different stabilities, and the calculated binding free energies between them also qualitatively agreed with the experimental results. Pair-interaction energy decomposition analyses of the complexes at FMO-MP2/6-31G(d) and aug-cc-pVDZ level of theory were performed using snapshot structures at 500 ns of simulations. The dispersion interaction characterized the interaction, and the order of total interaction energies between the guest molecules and CB[7] was also associated with the experimental results. A significant difference in electrostatic interaction energies was observed in conformer E, which was correlated with the stability of the guest molecules at the edge of CB[7]. The balance between the stabilities of these conformers was correlated with the affinity of guest molecules for CB[7].
{"title":"Modulation of the Intermolecular Interactions of Cucurbit[7]uril with Phenylalanine Derivatives by the Functional Groups","authors":"Kaori Ueno-Noto, Seina Toyama, Yuki Kono, Keiko Takano","doi":"10.1093/bulcsj/uoae077","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae077","url":null,"abstract":"\u0000 Intermolecular interactions in 1:1 inclusion complexes of cucurbit[7]uril (CB[7]) with phenylalanine derivatives were investigated by density functional theory (B97-D) calculations. For each complex, two optimized geometries were found: conformer C in which a guest molecule resided in the center of CB[7], and conformer E where a guest molecule was present at the edge of CB[7]. The order of energy differences between these conformers agreed well with previously reported differences in the affinity of guest molecules for CB[7]. Molecular dynamics simulations of the complexes showed that the guest molecules in CB[7] had different stabilities, and the calculated binding free energies between them also qualitatively agreed with the experimental results.\u0000 Pair-interaction energy decomposition analyses of the complexes at FMO-MP2/6-31G(d) and aug-cc-pVDZ level of theory were performed using snapshot structures at 500 ns of simulations. The dispersion interaction characterized the interaction, and the order of total interaction energies between the guest molecules and CB[7] was also associated with the experimental results. A significant difference in electrostatic interaction energies was observed in conformer E, which was correlated with the stability of the guest molecules at the edge of CB[7]. The balance between the stabilities of these conformers was correlated with the affinity of guest molecules for CB[7].","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sophisticated control of the spatial arrangement of gold nanorods provides significant advantages in the design of plasmonic systems. However, dynamic modulation of the gold nanorod spatial arrangements remains challenging. Here, we present a novel strategy for dynamic control of thermo-responsive gold nanorods with uniform alignment on a solid substrate using polymer brushes. In this system, cationic-thermo-responsive gold nanorods were immobilized into anionic polymer brushes via moderate electrostatic interactions, providing vertically aligned gold nanorod arrays. Upon heating, the gold nanorods were assembled while maintaining their vertical orientation within the polymer brushes. They returned to the original state upon cooling, indicating reversible assembly/disassembly. It is noticeable that this system exhibits rapid changes in nanostructure arrangement even when immobilized in the polymer brush substrate on a solid substrate rather than those dispersed in solution. Importantly, the gold nanorods showed good adhesion stability in polymer brushes without any significant detachment during washing and thermal cycling processes, but performed assembly formation even at largely separated conditions, indicating the traveling of considerable distances similar to the lateral diffusion of membrane proteins in cell membranes. In addition to providing unprecedented control over gold nanorod spatial configurations, our approach introduces a versatile platform for developing advanced plasmonic devices.
{"title":"Assembly/Disassembly Control of Gold Nanorods with Uniform Orientation on Anionic Polymer Brush Substrates","authors":"Jingyan Yang, Yu Sekizawa, Xu Shi, Kuniharu Ijiro, Hideyuki Mitomo","doi":"10.1093/bulcsj/uoae073","DOIUrl":"https://doi.org/10.1093/bulcsj/uoae073","url":null,"abstract":"Sophisticated control of the spatial arrangement of gold nanorods provides significant advantages in the design of plasmonic systems. However, dynamic modulation of the gold nanorod spatial arrangements remains challenging. Here, we present a novel strategy for dynamic control of thermo-responsive gold nanorods with uniform alignment on a solid substrate using polymer brushes. In this system, cationic-thermo-responsive gold nanorods were immobilized into anionic polymer brushes via moderate electrostatic interactions, providing vertically aligned gold nanorod arrays. Upon heating, the gold nanorods were assembled while maintaining their vertical orientation within the polymer brushes. They returned to the original state upon cooling, indicating reversible assembly/disassembly. It is noticeable that this system exhibits rapid changes in nanostructure arrangement even when immobilized in the polymer brush substrate on a solid substrate rather than those dispersed in solution. Importantly, the gold nanorods showed good adhesion stability in polymer brushes without any significant detachment during washing and thermal cycling processes, but performed assembly formation even at largely separated conditions, indicating the traveling of considerable distances similar to the lateral diffusion of membrane proteins in cell membranes. In addition to providing unprecedented control over gold nanorod spatial configurations, our approach introduces a versatile platform for developing advanced plasmonic devices.","PeriodicalId":9511,"journal":{"name":"Bulletin of the Chemical Society of Japan","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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