Nanographenes and polycyclic aromatic hydrocarbons exhibit many intriguing physical properties and have potential applications across a range of scientific fields, including electronics, catalysis, and biomedicine. To accelerate the development of such applications, efficient and reliable methods for accessing functionalized analogs are required. Herein, we report the efficient synthesis of functionalized small nanographenes from readily available iodobiaryl and diarylacetylene derivatives via a one-pot, multi-annulation sequence catalyzed by a single palladium catalyst. This method enables the preparation of small nanographenes bearing various polar functional groups, such as hydroxy, amino, and pyridinic nitrogen atoms, which are otherwise difficult to incorporate. These functional groups provide valuable sites for further derivatization, allowing the modulation of small nanographenes' solubility, optoelectronic properties, and photochromic and vapochromic behaviors. Our new method thus provides a platform for facile access to novel carbon-based materials.
{"title":"Rapid access to functionalized nanographenes through a palladium-catalyzed multi-annulation sequence","authors":"Takehisa Maekawa, Kenichiro Itami","doi":"10.1039/d4sc07995g","DOIUrl":"https://doi.org/10.1039/d4sc07995g","url":null,"abstract":"Nanographenes and polycyclic aromatic hydrocarbons exhibit many intriguing physical properties and have potential applications across a range of scientific fields, including electronics, catalysis, and biomedicine. To accelerate the development of such applications, efficient and reliable methods for accessing functionalized analogs are required. Herein, we report the efficient synthesis of functionalized small nanographenes from readily available iodobiaryl and diarylacetylene derivatives <em>via</em> a one-pot, multi-annulation sequence catalyzed by a single palladium catalyst. This method enables the preparation of small nanographenes bearing various polar functional groups, such as hydroxy, amino, and pyridinic nitrogen atoms, which are otherwise difficult to incorporate. These functional groups provide valuable sites for further derivatization, allowing the modulation of small nanographenes' solubility, optoelectronic properties, and photochromic and vapochromic behaviors. Our new method thus provides a platform for facile access to novel carbon-based materials.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"84 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic compounds present promising options for sustainable zinc battery electrodes. Nevertheless, the electrochemical properties of current organic electrodes still lag behind those of their inorganic counterparts. In this study, nitro groups were incorporated into pyrene-4, 5, 9, 10-tetraone (PTO), resulting in an elevated discharge voltage due to their strong electron-withdrawing capabilities. Additionally, a novel electrochemical conversion of nitro to azo groups was observed in aqueous electrolytes. This transformation can be leveraged to enhance cycling stability, especially at low current densities. The electrochemical process of nitro-PTO during discharge comprises three distinct steps. Initially, two stages of H+/Zn2+ coordination to the carbonyl groups led to a high capacity of ~284 mAh g−1 above 0.80 V—significantly higher than that of PTO. Further discharge irreversibly transformed -NO2 groups into N=N bonds, resulting in exceptionally high specific capacities of approximately 695 mAh g−1 and 905 mAh g−1 for PTO decorated with single and double -NO2 groups, respectively. As -NO2 was continuously reduced to N=N, the resultant azo-conjugated PTO (PTO-Azo) demonstrated reversible H+/Zn2+ co-storage and release during subsequent charge/discharge cycles, with improved capacity retention and higher kinetics. This work, therefore, elucidates the impact of nitro group chemistry on the electrochemical performance of carbonyl-rich organic electrodes.
{"title":"Enhancing Organic Cathodes of Aqueous Zinc-Ion Batteries via Nitro Group Modification","authors":"Donghong Wang, Mengxuan Qin, Changyou Zhang, Mengxue Li, Chao Peng, Chunyi Zhi, Qing Li, Lei Zhu","doi":"10.1039/d4sc08514k","DOIUrl":"https://doi.org/10.1039/d4sc08514k","url":null,"abstract":"Organic compounds present promising options for sustainable zinc battery electrodes. Nevertheless, the electrochemical properties of current organic electrodes still lag behind those of their inorganic counterparts. In this study, nitro groups were incorporated into pyrene-4, 5, 9, 10-tetraone (PTO), resulting in an elevated discharge voltage due to their strong electron-withdrawing capabilities. Additionally, a novel electrochemical conversion of nitro to azo groups was observed in aqueous electrolytes. This transformation can be leveraged to enhance cycling stability, especially at low current densities. The electrochemical process of nitro-PTO during discharge comprises three distinct steps. Initially, two stages of H+/Zn2+ coordination to the carbonyl groups led to a high capacity of ~284 mAh g−1 above 0.80 V—significantly higher than that of PTO. Further discharge irreversibly transformed -NO2 groups into N=N bonds, resulting in exceptionally high specific capacities of approximately 695 mAh g−1 and 905 mAh g−1 for PTO decorated with single and double -NO2 groups, respectively. As -NO2 was continuously reduced to N=N, the resultant azo-conjugated PTO (PTO-Azo) demonstrated reversible H+/Zn2+ co-storage and release during subsequent charge/discharge cycles, with improved capacity retention and higher kinetics. This work, therefore, elucidates the impact of nitro group chemistry on the electrochemical performance of carbonyl-rich organic electrodes.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"102 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Precise molecular recognition depends on the delicate interplay between a guest molecule and a host possessing complementary functional groups. De novo design of selective artificial receptors remains a formidable challenge, given the complexity of predicting these interactions. We present herein a bottom-up approach to the evolution of selective molecular receptor through precise endo-functionalization of a supramolecular cage. Internal functional groups were introduced within the heteroleptic palladium coordination cage in a site-precise fashion. With just five different functional groups, we successfully created a library of 32 isoreticular nano-cages, each featuring unique micro-environments, by varying the nature, location and combination of endo-functional groups. The nano-cage exhibited adaptive recognition ability towards guest molecules of distinct geometries and hydrogen bonding capabilities. Titration experiments demonstrated that the binding affinity for a specific guest can be finely tuned and optimized by changing the endo-functional groups. As a proof of principle, by strategically screening our nano-cage library, we identified a receptor with high affinity and specificity for the dihydrogen phosphate guest. X-ray analysis and DFT calculation highlighted the pivotal role of the synergistic interactions among distinct endo-functional groups in achieving high-fidelity molecular recognition. This study is expected to provide a versatile solution for the bottom-up construction of tailor-made molecular receptors.
{"title":"Synthesis of Precisely Functionalized Nano-confinement: a Bottom-up Approach to the Evolution of Selective Molecular Receptors","authors":"Ya-Mei Tan, Lu-Mei Zhang, Qixia Bai, Zhe Zhang, Pingshan Wang, Qi Zhang","doi":"10.1039/d4sc08176e","DOIUrl":"https://doi.org/10.1039/d4sc08176e","url":null,"abstract":"<strong>Abstract</strong>: Precise molecular recognition depends on the delicate interplay between a guest molecule and a host possessing complementary functional groups. De novo design of selective artificial receptors remains a formidable challenge, given the complexity of predicting these interactions. We present herein a bottom-up approach to the evolution of selective molecular receptor through precise endo-functionalization of a supramolecular cage. Internal functional groups were introduced within the heteroleptic palladium coordination cage in a site-precise fashion. With just five different functional groups, we successfully created a library of 32 isoreticular nano-cages, each featuring unique micro-environments, by varying the nature, location and combination of endo-functional groups. The nano-cage exhibited adaptive recognition ability towards guest molecules of distinct geometries and hydrogen bonding capabilities. Titration experiments demonstrated that the binding affinity for a specific guest can be finely tuned and optimized by changing the endo-functional groups. As a proof of principle, by strategically screening our nano-cage library, we identified a receptor with high affinity and specificity for the dihydrogen phosphate guest. X-ray analysis and DFT calculation highlighted the pivotal role of the synergistic interactions among distinct endo-functional groups in achieving high-fidelity molecular recognition. This study is expected to provide a versatile solution for the bottom-up construction of tailor-made molecular receptors.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"198 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Single-atom catalysts (SACs) dispersed on support materials exhibit exceptional catalytic properties that can be fine-tuned through interactions between the single atoms and the support. However, selectively controlling the spatial location of single metal atoms while simultaneously harmonizing their coordination environment remains a significant challenge. Here, we present a phenolic-mediated interfacial anchoring (PIA) strategy to prepare SACs with Fe single atoms anchored on the surface of heteroatom-doped carbon nanospheres. Briefly, by exploiting the metal-phenolic networks (MPNs) for the surface coating and phloroglucinol-induced polymerization for the support precursor formation, we successfully anchored Fe single atoms at the interface between the MPN layer and the support surface. Moreover, this anchoring strategy effectively prevents Fe species from clustering or migrating toward the interior of the support during thermal treatment, resulting in atomically dispersed FeN3P-SAC exhibits a high metallic utilization efficiency and comparable peroxidase-like catalytic activity and kinetics to natural enzymes. As a proof-of-concept demonstration, FeN3P-SAC could effectively block the growth of tumor cells in vitro by combining excellent tumor penetration and the ability to activate chemodynamic and photothermal effects synergistically. This work advances the development of highly active SACs with MPN-based nanotechnology, providing a promising approach for nanocatalytic tumor therapy.
{"title":"Surface immobilization of single atoms on heteroatom-doped carbon nanospheres through phenolic-mediated interfacial anchoring for highly efficient biocatalysis","authors":"Yajing Zhang, Yunxiang He, Yun Jiao, Guobin Yang, Yiran Pu, Zhangmin Wan, Shuyun Li, Yan-Chao Wu, Wen Liao, Junling Guo","doi":"10.1039/d4sc07775j","DOIUrl":"https://doi.org/10.1039/d4sc07775j","url":null,"abstract":"Single-atom catalysts (SACs) dispersed on support materials exhibit exceptional catalytic properties that can be fine-tuned through interactions between the single atoms and the support. However, selectively controlling the spatial location of single metal atoms while simultaneously harmonizing their coordination environment remains a significant challenge. Here, we present a phenolic-mediated interfacial anchoring (PIA) strategy to prepare SACs with Fe single atoms anchored on the surface of heteroatom-doped carbon nanospheres. Briefly, by exploiting the metal-phenolic networks (MPNs) for the surface coating and phloroglucinol-induced polymerization for the support precursor formation, we successfully anchored Fe single atoms at the interface between the MPN layer and the support surface. Moreover, this anchoring strategy effectively prevents Fe species from clustering or migrating toward the interior of the support during thermal treatment, resulting in atomically dispersed FeN<small><sub>3</sub></small>P-SAC exhibits a high metallic utilization efficiency and comparable peroxidase-like catalytic activity and kinetics to natural enzymes. As a proof-of-concept demonstration, FeN<small><sub>3</sub></small>P-SAC could effectively block the growth of tumor cells in vitro by combining excellent tumor penetration and the ability to activate chemodynamic and photothermal effects synergistically. This work advances the development of highly active SACs with MPN-based nanotechnology, providing a promising approach for nanocatalytic tumor therapy.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"20 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akankshika Parida, Gargee Bhattacharyya, Swagatika Mallik, Rabindra K Behera
The self-assembled ferritin protein nanocage plays a pivotal role during oxidative stress, iron metabolism, and host-pathogen interaction by executing rapid iron uptake, oxidation and its safe-storage. Self-assembly creates a nanocompartment and various pores/channels for the uptake of charged substrates (Fe2+) and develops a concentration gradient across the protein shell. This phenomenon fuels the rapid ferroxidase activity by an upsurge in the substrate concentration at the catalytic sites. However, it is difficult to segregate the relative contribution of the catalytic sites and self-assembly towards rapid ferroxidase/mineralization activity owing to the inherent self-assembly propensity of ferritins. In the current work, 3-fold pore electrostatics of bacterioferritin from Mycobacterium tuberculosis was rationally altered by site-directed mutagenesis to generate self-assembled (E121A, E121Q) and assembly-defective (E121K, E121F) variants. In comparison to autoxidation of Fe2+ in buffer, the assembly-defective variants exhibited a significantly faster ferroxidase/mineralization activity and O2 consumption kinetics due to their functional catalytic sites, but failed to level-up with the self-assembled variants even at 100-fold higher Fe2+ concentration. Only the self-assembled variants exhibited cooperativity in iron oxidation, maintained biomineral solubility, and protected DNA against Fenton reaction. This report highlights the concerted effect of self-assembly and ferroxidase sites that propels the rapid Fe2+ uptake, its oxidation and biomineralization in bacterioferritin. The findings also establish the importance of electrostatic guiding and nanoconfinement offered by ferritin self-assembly towards its enzymatic activity and antioxidative property. Moreover, this work identifies the key electrostatic interactions (“hot-spots”) at the subunit contact points that control the cage/pore formation, impart cage stability and influences ferritin’s natural functions. Manipulation of hot-spot residues can be further extended towards encapsulation of cargo, for various bio-medical applications, by strategically inducing its disassembly and subsequent reassembly by adjustments in the ionic strength. This would bypass the need for extreme/harsh reaction conditions and minimize the loss of cargo/protein.
{"title":"Rational pore engineering reveals the relative contribution of enzymatic sites and self-assembly towards rapid ferroxidase activity and mineralization: Impact of electrostatic guiding and cage-confinement in bacterioferritin","authors":"Akankshika Parida, Gargee Bhattacharyya, Swagatika Mallik, Rabindra K Behera","doi":"10.1039/d4sc07021f","DOIUrl":"https://doi.org/10.1039/d4sc07021f","url":null,"abstract":"The self-assembled ferritin protein nanocage plays a pivotal role during oxidative stress, iron metabolism, and host-pathogen interaction by executing rapid iron uptake, oxidation and its safe-storage. Self-assembly creates a nanocompartment and various pores/channels for the uptake of charged substrates (Fe2+) and develops a concentration gradient across the protein shell. This phenomenon fuels the rapid ferroxidase activity by an upsurge in the substrate concentration at the catalytic sites. However, it is difficult to segregate the relative contribution of the catalytic sites and self-assembly towards rapid ferroxidase/mineralization activity owing to the inherent self-assembly propensity of ferritins. In the current work, 3-fold pore electrostatics of bacterioferritin from Mycobacterium tuberculosis was rationally altered by site-directed mutagenesis to generate self-assembled (E121A, E121Q) and assembly-defective (E121K, E121F) variants. In comparison to autoxidation of Fe2+ in buffer, the assembly-defective variants exhibited a significantly faster ferroxidase/mineralization activity and O2 consumption kinetics due to their functional catalytic sites, but failed to level-up with the self-assembled variants even at 100-fold higher Fe2+ concentration. Only the self-assembled variants exhibited cooperativity in iron oxidation, maintained biomineral solubility, and protected DNA against Fenton reaction. This report highlights the concerted effect of self-assembly and ferroxidase sites that propels the rapid Fe2+ uptake, its oxidation and biomineralization in bacterioferritin. The findings also establish the importance of electrostatic guiding and nanoconfinement offered by ferritin self-assembly towards its enzymatic activity and antioxidative property. Moreover, this work identifies the key electrostatic interactions (“hot-spots”) at the subunit contact points that control the cage/pore formation, impart cage stability and influences ferritin’s natural functions. Manipulation of hot-spot residues can be further extended towards encapsulation of cargo, for various bio-medical applications, by strategically inducing its disassembly and subsequent reassembly by adjustments in the ionic strength. This would bypass the need for extreme/harsh reaction conditions and minimize the loss of cargo/protein.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"8 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the unprecedent research development on lead halide perovskite photovoltaics, scaling up the fabrication while comprehensively understanding the properties of cost-effective and highly uniform precursor film has become critical for their applicational promotion. When enlarging the device area, good precursor purity serves as the first step on ensuring the uniformity of perovskite film. Chemical purity and the colloidal uniformity in precursor solution all play important roles on dictating the film uniformity and defect density. Here we, for the first time, explore the colloidal behavior of FAPbI3 precursor using different preparatory materials of varied costs but with similar metal purity. As the regular PbI2+FAI powder precursors’ colloidal size increases compared to PbI2 colloids, the FAPbI3 single crystal precursor synthesized from low-purity chemicals exhibits a generally smaller and more uniform colloid size, which yields perovskite films of improved uniformity and reduced defect density at lower expenses. The colloidally uniform single crystal precursors lead to photovoltaics with higher power conversion efficiency and better long-term operational stability. More importantly, the uniformity in precursor and film is beneficial for large-area fabrication, where the scaling-up production of 30 cm × 30 cm perovskite submodules based on single crystal precursors achieve an impressive 20.7% efficiency.
{"title":"Colloidally Uniform Single Crystal Precursors Enable Uniform FAPbI3 Films for Efficient Perovskite Submodules","authors":"Yugang Liang, Yingping Fan, Zhixiao Qin, Lei Lu, Haifei Wang, Meng Ren, Fang Liu, Yanfeng Miao, Yuetian Chen, Yixin Zhao","doi":"10.1039/d4sc07759h","DOIUrl":"https://doi.org/10.1039/d4sc07759h","url":null,"abstract":"With the unprecedent research development on lead halide perovskite photovoltaics, scaling up the fabrication while comprehensively understanding the properties of cost-effective and highly uniform precursor film has become critical for their applicational promotion. When enlarging the device area, good precursor purity serves as the first step on ensuring the uniformity of perovskite film. Chemical purity and the colloidal uniformity in precursor solution all play important roles on dictating the film uniformity and defect density. Here we, for the first time, explore the colloidal behavior of FAPbI<small><sub>3</sub></small> precursor using different preparatory materials of varied costs but with similar metal purity. As the regular PbI<small><sub>2</sub></small>+FAI powder precursors’ colloidal size increases compared to PbI<small><sub>2</sub></small> colloids, the FAPbI<small><sub>3</sub></small> single crystal precursor synthesized from low-purity chemicals exhibits a generally smaller and more uniform colloid size, which yields perovskite films of improved uniformity and reduced defect density at lower expenses. The colloidally uniform single crystal precursors lead to photovoltaics with higher power conversion efficiency and better long-term operational stability. More importantly, the uniformity in precursor and film is beneficial for large-area fabrication, where the scaling-up production of 30 cm × 30 cm perovskite submodules based on single crystal precursors achieve an impressive 20.7% efficiency.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"80 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samira Amini, Kerstin Oppelt, Olivier Blacque, Mikhail Agrachev, Gunnar Jeschke, Felix Zelder
Cofactor F430 is a nickel-containing hydrocorphinato complex that plays important roles in the enzymatic formation and oxidation of methane. In methanotrophic bacteria, F430-dependent methyl-coenzyme M reductase (MCR) catalyses the endergonic conversion of the heterodisulfide adduct of coenzymes M and B with methane to methyl-coenzyme M and coenzyme B. In a radical mechanism, the Ni(I)-induced formation of a transient thiyl radical of coenzyme B from the heterodisulfide has been proposed. Herein, we introduce a new semi-artificial Ni-complex derived from vitamin B12 as functional model of F430. We demonstrate with electrochemical studies that the low valent Ni(I) complex cleaves the biomimetic model compound diphenyl disulfide into approx. 0.5 equivalents of thiophenol and a transient thiophenyl radical at a potential of -1.65 V vs. Fc/Fc+. The thiyl radical is trapped in solution with phenylacetylene as thiophenyl-substituted olefins, but also leads to degradation of the Ni-complex.
{"title":"Biomimetic Thiyl Radical Formation From Diphenyl Disulfide with The Low Valent Ni(I) State of A Cofactor F430 Model","authors":"Samira Amini, Kerstin Oppelt, Olivier Blacque, Mikhail Agrachev, Gunnar Jeschke, Felix Zelder","doi":"10.1039/d4sc08416k","DOIUrl":"https://doi.org/10.1039/d4sc08416k","url":null,"abstract":"Cofactor F430 is a nickel-containing hydrocorphinato complex that plays important roles in the enzymatic formation and oxidation of methane. In methanotrophic bacteria, F430-dependent methyl-coenzyme M reductase (MCR) catalyses the endergonic conversion of the heterodisulfide adduct of coenzymes M and B with methane to methyl-coenzyme M and coenzyme B. In a radical mechanism, the Ni(I)-induced formation of a transient thiyl radical of coenzyme B from the heterodisulfide has been proposed. Herein, we introduce a new semi-artificial Ni-complex derived from vitamin B12 as functional model of F430. We demonstrate with electrochemical studies that the low valent Ni(I) complex cleaves the biomimetic model compound diphenyl disulfide into approx. 0.5 equivalents of thiophenol and a transient thiophenyl radical at a potential of -1.65 V vs. Fc/Fc+. The thiyl radical is trapped in solution with phenylacetylene as thiophenyl-substituted olefins, but also leads to degradation of the Ni-complex.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"100 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the oxygen reduction reaction (ORR) mechanism and accurately characterizing the reaction interface are essential for improving fuel cell efficiency. We developed an active learning framework combining utilized machine learning force fields and enhanced sampling to explore dynamics and kinetics of ORR on Fe-N4/C under a fully explicit solvent model. Different possible reaction paths have been explored and the O2 adsorption process is confirmed as the rate-determining step of ORR at the Fe-N4/C-water interface, which needs to overcome a free energy barrier of 0.39 eV. By statistical analysis of solvent configurations for proton-coupled electron transfer (PCET) processes, it is revealed that the configurations of interface water remarkably influence the reaction efficiency. More hydrogen bonds and longer lifetime facilitates the PCET reactions and even make them barrierless. Our theoretical framework highlights the significance of solvent configurations in determining free energy barriers, and offers new insights into the reaction mechanism of ORR on Fe-N4/C catalysts.
{"title":"Dynamics and Kinetic Exploration of Oxygen Reduction Reaction at Fe-N4/C-water Interface Accelerated by Machine Learning Force Field","authors":"Qinghan Yu, Pai Li, Xing Ni, Youyong Li, Lu Wang","doi":"10.1039/d4sc06422d","DOIUrl":"https://doi.org/10.1039/d4sc06422d","url":null,"abstract":"Understanding the oxygen reduction reaction (ORR) mechanism and accurately characterizing the reaction interface are essential for improving fuel cell efficiency. We developed an active learning framework combining utilized machine learning force fields and enhanced sampling to explore dynamics and kinetics of ORR on Fe-N4/C under a fully explicit solvent model. Different possible reaction paths have been explored and the O2 adsorption process is confirmed as the rate-determining step of ORR at the Fe-N4/C-water interface, which needs to overcome a free energy barrier of 0.39 eV. By statistical analysis of solvent configurations for proton-coupled electron transfer (PCET) processes, it is revealed that the configurations of interface water remarkably influence the reaction efficiency. More hydrogen bonds and longer lifetime facilitates the PCET reactions and even make them barrierless. Our theoretical framework highlights the significance of solvent configurations in determining free energy barriers, and offers new insights into the reaction mechanism of ORR on Fe-N4/C catalysts.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"74 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atomically precise gold nanoclusters have shown great promise as model elctrocatalysts in pivotal electrocatalytic processes such as hydrogen evolution reaction (HER) and carbon dioxide reduction reaction (CO2RR). Although the influence of ligands on the electronic properties of these nanoclusters are well acknowledged, the ligand effects on their electrocatalytic performances have been rarely explored. Herein, using [Au25(SR)18]- nanocluster as the prototype model, we demonstrated the importance of ligand hydrophilicity versus hydrophobicity in modulating the interface dynamics and electrocatalytic performance. Our first-principle computations revealed that Au25 protected by hydrophilic -SCH2COOH ligands dictates faster kinetics in stripping the thiolate ligand and exhibits better HER activity due to enhanced proton transfer facilitated by boosted interface hydrogen bonding. Conversely, Au25 protected by hydrophobic -SCH2CH3 ligands demonstrates enhanced CO2RR performance by minimizing water interference to stabilize the key *COOH intermediate and lower the barrier for CO formation. Experimental validation using synthesized hydrophilic and hydrophobic ligand-protected Au25 nanoclusters (NCs), such as [Au25(MPA)18]- (MPA = Mercaptopropionic acid), [Au25(MHA)18]- (MHA = 6-Mercaptohexanoic acid), and [Au25(SC6H13)18]-, confirms these findings, where the hydrophilic ligand-protected Au25 NCs exhibit better activity and stability in HER, while the hydrophobic ligand-protected Au25 NCs achieve higher Faradaic efficiency and current density in CO2RR. The mechanistic insights in this study provide valuable guidance for the rational design of surface microenvironment in efficient nanocatalysts for sustainable energy applications.
{"title":"Ligand-induced Changes in the Electrocatalytic Activity of Atomically Precise Au₂₅ Nanoclusters","authors":"Lipan Luo, Xia Zhou, Yuping Chen, Fang Sun, Likai Wang, Qing Tang","doi":"10.1039/d4sc07181f","DOIUrl":"https://doi.org/10.1039/d4sc07181f","url":null,"abstract":"Atomically precise gold nanoclusters have shown great promise as model elctrocatalysts in pivotal electrocatalytic processes such as hydrogen evolution reaction (HER) and carbon dioxide reduction reaction (CO2RR). Although the influence of ligands on the electronic properties of these nanoclusters are well acknowledged, the ligand effects on their electrocatalytic performances have been rarely explored. Herein, using [Au25(SR)18]- nanocluster as the prototype model, we demonstrated the importance of ligand hydrophilicity versus hydrophobicity in modulating the interface dynamics and electrocatalytic performance. Our first-principle computations revealed that Au25 protected by hydrophilic -SCH2COOH ligands dictates faster kinetics in stripping the thiolate ligand and exhibits better HER activity due to enhanced proton transfer facilitated by boosted interface hydrogen bonding. Conversely, Au25 protected by hydrophobic -SCH2CH3 ligands demonstrates enhanced CO2RR performance by minimizing water interference to stabilize the key *COOH intermediate and lower the barrier for CO formation. Experimental validation using synthesized hydrophilic and hydrophobic ligand-protected Au25 nanoclusters (NCs), such as [Au25(MPA)18]- (MPA = Mercaptopropionic acid), [Au25(MHA)18]- (MHA = 6-Mercaptohexanoic acid), and [Au25(SC6H13)18]-, confirms these findings, where the hydrophilic ligand-protected Au25 NCs exhibit better activity and stability in HER, while the hydrophobic ligand-protected Au25 NCs achieve higher Faradaic efficiency and current density in CO2RR. The mechanistic insights in this study provide valuable guidance for the rational design of surface microenvironment in efficient nanocatalysts for sustainable energy applications.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"18 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Amanda Ekanayake, Haoxin Mai, Dehong Chen, Rachel A. Caruso
High-temperature reduction of TiO2 causes the gradual formation of structural defects, leading to oxygen vacancy planar defects and giving rise to Magnéli phases, which are substoichiometric titanium oxides that follow the formula TinO2n−1, with 4 ≤ n ≤ 9. A high concentration of defects provides several possible configurations for Ti4+ and Ti3+ within the crystal, with the variation in charge ordered states changing the electronic structure of the material. The changes in crystal and electronic structures of Magnéli phases introduce unique properties absent in TiO2, facilitating their diverse applications. Their exceptional electrical conductivity, stability in harsh chemical environments and capability to generate hydroxyl radicals make them highly valuable in electrochemical applications. Additionally, their high specific capacity and corrosion resistance make them ideal for energy storage facilities. These properties, combined with excellent solar light absorption, have led to their widespread use in electrochemical, photochemical, photothermal, catalytic and energy storage applications. To provide a complete overview of the formation, properties, and environmental- and energy-related applications of Magnéli phase titanium suboxides, this review initially highlights the crystal structure and the physical, thermoelectrical and optical properties of these materials. The conventional and novel strategies developed to synthesise these materials are then discussed, along with potential approaches to overcome challenges associated with current issues and future low-energy fabrication methods. Finally, we provide a comprehensive overview of their applications across various fields, including environmental remediation, energy storage, and thermoelectric and optoelectronic technologies. We also discuss promising new directions for the use of Magnéli phase titanium suboxides and solutions to challenges in energy and environment-related applications, and provide guidance on how these materials can be developed and utilised to meet diverse research application needs. By making use of control measures to mitigate the potential hazards associated with their nanoparticles, Magnéli phases can be considered as versatile materials with potential for next generation energy needs.
{"title":"Recent advances in synthesis and application of Magnéli phase titanium oxides for energy storage and environmental remediation","authors":"S. Amanda Ekanayake, Haoxin Mai, Dehong Chen, Rachel A. Caruso","doi":"10.1039/d4sc04477k","DOIUrl":"https://doi.org/10.1039/d4sc04477k","url":null,"abstract":"High-temperature reduction of TiO<small><sub>2</sub></small> causes the gradual formation of structural defects, leading to oxygen vacancy planar defects and giving rise to Magnéli phases, which are substoichiometric titanium oxides that follow the formula Ti<small><sub><em>n</em></sub></small>O<small><sub>2<em>n</em>−1</sub></small>, with 4 ≤ <em>n</em> ≤ 9. A high concentration of defects provides several possible configurations for Ti<small><sup>4+</sup></small> and Ti<small><sup>3+</sup></small> within the crystal, with the variation in charge ordered states changing the electronic structure of the material. The changes in crystal and electronic structures of Magnéli phases introduce unique properties absent in TiO<small><sub>2</sub></small>, facilitating their diverse applications. Their exceptional electrical conductivity, stability in harsh chemical environments and capability to generate hydroxyl radicals make them highly valuable in electrochemical applications. Additionally, their high specific capacity and corrosion resistance make them ideal for energy storage facilities. These properties, combined with excellent solar light absorption, have led to their widespread use in electrochemical, photochemical, photothermal, catalytic and energy storage applications. To provide a complete overview of the formation, properties, and environmental- and energy-related applications of Magnéli phase titanium suboxides, this review initially highlights the crystal structure and the physical, thermoelectrical and optical properties of these materials. The conventional and novel strategies developed to synthesise these materials are then discussed, along with potential approaches to overcome challenges associated with current issues and future low-energy fabrication methods. Finally, we provide a comprehensive overview of their applications across various fields, including environmental remediation, energy storage, and thermoelectric and optoelectronic technologies. We also discuss promising new directions for the use of Magnéli phase titanium suboxides and solutions to challenges in energy and environment-related applications, and provide guidance on how these materials can be developed and utilised to meet diverse research application needs. By making use of control measures to mitigate the potential hazards associated with their nanoparticles, Magnéli phases can be considered as versatile materials with potential for next generation energy needs.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"31 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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