Irina Kotova, Tatyana S. Spiridonova, Aleksandra Savina, E. G. Khaikina, Sergey F. Solodovnikov, Zoya A. Solodovnikova, Hyun-Joo Koo, Myung-Hwan Whangbo, Yevgeny Ovchenkov, Konstantin Zakharov, Larisa Victorovna Shvanskaya, Tatyana M. Vasilchikova, Alexander Vasiliev
We prepared a new compound, AgCo3Cr(MoO4)5, and characterized its crystal structure and physical properties. It crystallizes in the triclinic space group P1 @#x0305; with mixed occupations of the transition-metal sites M = (Co, Cr). The Ag site is split into three close positions. The magnetic subsystem of the title compound consists of M2O10 dimers and M3O14 trimers, made up of edge-sharing MO6 octahedra. These units are interconnected by MoO4 tetrahedra. Both ac and dc magnetic susceptibility, as well as specific heat and dielectric permittivity, evidence a ferrimagnetic behavior below at Tferri = 5.5 K. To investigate the properties of this nanostructured system, we evaluated the spin exchanges for the four most probable magnetic ion arrangements. We found that considering the local structure is essential for understanding the behavior of a magnet with mixed occupations of the transition metal sites.
{"title":"Crystal structure and ferrimagnetism of AgCo3Cr(MoO4)5 with mixed occupation of the transition metal sites","authors":"Irina Kotova, Tatyana S. Spiridonova, Aleksandra Savina, E. G. Khaikina, Sergey F. Solodovnikov, Zoya A. Solodovnikova, Hyun-Joo Koo, Myung-Hwan Whangbo, Yevgeny Ovchenkov, Konstantin Zakharov, Larisa Victorovna Shvanskaya, Tatyana M. Vasilchikova, Alexander Vasiliev","doi":"10.1039/d4dt03353a","DOIUrl":"https://doi.org/10.1039/d4dt03353a","url":null,"abstract":"We prepared a new compound, AgCo3Cr(MoO4)5, and characterized its crystal structure and physical properties. It crystallizes in the triclinic space group P1 @#x0305; with mixed occupations of the transition-metal sites M = (Co, Cr). The Ag site is split into three close positions. The magnetic subsystem of the title compound consists of M2O10 dimers and M3O14 trimers, made up of edge-sharing MO6 octahedra. These units are interconnected by MoO4 tetrahedra. Both ac and dc magnetic susceptibility, as well as specific heat and dielectric permittivity, evidence a ferrimagnetic behavior below at Tferri = 5.5 K. To investigate the properties of this nanostructured system, we evaluated the spin exchanges for the four most probable magnetic ion arrangements. We found that considering the local structure is essential for understanding the behavior of a magnet with mixed occupations of the transition metal sites.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"7 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462512","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}
Eva Pugliese, Damien Coutancier, Paul-Alexis PAVARD, Julien Hervochon, Bram van der Linden, Nicolas Casaretto, Sophie Bourcier, Geoffrey Pourtois, Murielle Bouttemy, Audrey Auffrant, Nathanaelle Schneider
Two novel gallium precursors for Atomic Layer Deposition (ALD), LGaMe₂ and LGa(NMe₂)₂ with L = N,N’-di-tertbutylacetamidinato, were successfully synthesised from a carbodiimide and gallium trichloride. The compounds were characterised by NMR spectroscopy and HR-mass spectrometry, confirming their monomeric nature. Their surface reactivity under ALD conditions with H₂O and H₂S co-reactants was explored using in-situ quartz crystal microbalance (QCM) measurements. LGaMe₂, bearing methyl ligands, was found to inhibit film growth, with deposition halting after three cycles. In contrast, LGa(NMe₂)₂ facilitated the successful growth of films using both H₂O and H₂S leading to Ga2O3 and Ga2S3 respectively, as confirmed by additional thin film ex-situ characterisation.This study underscores the critical role of auxiliary X ligands (here Me or NMe₂) in determining ALD process efficiency, and emphasises the complexity and unique nature of surface chemistry compared to solution-phase behaviour.
{"title":"Unveiling surface reactivity: the crucial role of auxiliary ligands in Gallium amidinate-based precursors for Atomic Layer Deposition","authors":"Eva Pugliese, Damien Coutancier, Paul-Alexis PAVARD, Julien Hervochon, Bram van der Linden, Nicolas Casaretto, Sophie Bourcier, Geoffrey Pourtois, Murielle Bouttemy, Audrey Auffrant, Nathanaelle Schneider","doi":"10.1039/d4dt03498h","DOIUrl":"https://doi.org/10.1039/d4dt03498h","url":null,"abstract":"Two novel gallium precursors for Atomic Layer Deposition (ALD), LGaMe₂ and LGa(NMe₂)₂ with L = N,N’-di-tertbutylacetamidinato, were successfully synthesised from a carbodiimide and gallium trichloride. The compounds were characterised by NMR spectroscopy and HR-mass spectrometry, confirming their monomeric nature. Their surface reactivity under ALD conditions with H₂O and H₂S co-reactants was explored using in-situ quartz crystal microbalance (QCM) measurements. LGaMe₂, bearing methyl ligands, was found to inhibit film growth, with deposition halting after three cycles. In contrast, LGa(NMe₂)₂ facilitated the successful growth of films using both H₂O and H₂S leading to Ga2O3 and Ga2S3 respectively, as confirmed by additional thin film ex-situ characterisation.This study underscores the critical role of auxiliary X ligands (here Me or NMe₂) in determining ALD process efficiency, and emphasises the complexity and unique nature of surface chemistry compared to solution-phase behaviour.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"52 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462513","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}
Simon J Clarke, Nicola Kelly, Ivan da Silva, Katherine Mary Steele, Heather Grievson
Reversible lithium intercalation into the van der Waals phase V2Te2O, forming new phases LixV2Te2O with x approaching 2, is reported using both chemical and electrochemical methods. The progress of each reaction was followed using powder X-ray diffraction and the crystal structure of the intercalated phase with x = 1, LiV2Te2O was refined using powder neutron diffraction. The intercalated Li ions occupy vacant pseudo-octahedral sites and the unit cell expands on reduction with no change in symmetry. The lithium ions can be removed chemically or electrochemically, making this the first known oxytelluride to undergo reversible lithium intercalation.
{"title":"Chemical and Electrochemical Lithiation of Van Der Waals Oxytelluride V2Te2O","authors":"Simon J Clarke, Nicola Kelly, Ivan da Silva, Katherine Mary Steele, Heather Grievson","doi":"10.1039/d5dt00159e","DOIUrl":"https://doi.org/10.1039/d5dt00159e","url":null,"abstract":"Reversible lithium intercalation into the van der Waals phase V2Te2O, forming new phases LixV2Te2O with x approaching 2, is reported using both chemical and electrochemical methods. The progress of each reaction was followed using powder X-ray diffraction and the crystal structure of the intercalated phase with x = 1, LiV2Te2O was refined using powder neutron diffraction. The intercalated Li ions occupy vacant pseudo-octahedral sites and the unit cell expands on reduction with no change in symmetry. The lithium ions can be removed chemically or electrochemically, making this the first known oxytelluride to undergo reversible lithium intercalation.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"2 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462519","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}
Laurent Sévery, T. Alexander Wheeler, Amelie Nicolay, Simon Teat, T. Don Tilley
The dinucleating ligand, 1,8-naphthyridine-2,7-bis(2,6-diisopropylphenyl)carboxamide (NBDA), was synthesized by palladium-catalyzed aminocarbonylation. This ligand was treated with two equivalents of mesitylcopper in the presence of [nBu4N]X (X = Cl, N3) to give the anionic complexes [nBu4N][Cu2(NBDA)(μ-Cl)] and [nBu4N][Cu2(NBDA)(μ-N3)]. Treatment of H2NBDA with mesitylcopper and two equivalents of xylyl isocyanide led to the formation of a charge-neutral dicopper(I) complex, [Cu2(NBDA)(CNXyl)2], displaying two isocyanide ligands, each terminally bound to one of the copper atoms. The complexes were characterized by NMR and IR spectroscopy, as well as by single-crystal X-ray diffraction analysis. Electrochemical characterization of the complexes using cyclic voltammetry revealed a reversible ligand-based reduction between –1.65 and –2.0 V vs. Fc/Fc+. DFT calculations suggest a more ionic bonding character and weaker Cu–Cu interactions in the NBDA complexes compared to those with other 1,8-naphthyridine-based ligands. This is congruent with intermetallic separations of over 3 Å induced by relatively strong coordination of the copper atoms to the amide nitrogen donor atoms observed in the solid state molecular structures.
{"title":"Dicopper(I) Complexes of a Binucleating, Dianionic, Naphthyridine Bis(amide) Ligand","authors":"Laurent Sévery, T. Alexander Wheeler, Amelie Nicolay, Simon Teat, T. Don Tilley","doi":"10.1039/d5dt00034c","DOIUrl":"https://doi.org/10.1039/d5dt00034c","url":null,"abstract":"The dinucleating ligand, 1,8-naphthyridine-2,7-bis(2,6-diisopropylphenyl)carboxamide (NBDA), was synthesized by palladium-catalyzed aminocarbonylation. This ligand was treated with two equivalents of mesitylcopper in the presence of [<small><sup>n</sup></small>Bu<small><sub>4</sub></small>N]X (X = Cl, N<small><sub>3</sub></small>) to give the anionic complexes [<small><sup>n</sup></small>Bu<small><sub>4</sub></small>N][Cu<small><sub>2</sub></small>(NBDA)(μ-Cl)] and [<small><sup>n</sup></small>Bu<small><sub>4</sub></small>N][Cu<small><sub>2</sub></small>(NBDA)(μ-N<small><sub>3</sub></small>)]. Treatment of H<small><sub>2</sub></small>NBDA with mesitylcopper and two equivalents of xylyl isocyanide led to the formation of a charge-neutral dicopper(I) complex, [Cu<small><sub>2</sub></small>(NBDA)(CNXyl)<small><sub>2</sub></small>], displaying two isocyanide ligands, each terminally bound to one of the copper atoms. The complexes were characterized by NMR and IR spectroscopy, as well as by single-crystal X-ray diffraction analysis. Electrochemical characterization of the complexes using cyclic voltammetry revealed a reversible ligand-based reduction between –1.65 and –2.0 V vs. Fc/Fc<small><sup>+</sup></small>. DFT calculations suggest a more ionic bonding character and weaker Cu–Cu interactions in the NBDA complexes compared to those with other 1,8-naphthyridine-based ligands. This is congruent with intermetallic separations of over 3 Å induced by relatively strong coordination of the copper atoms to the amide nitrogen donor atoms observed in the solid state molecular structures.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"15 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470987","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}
Jiangtian Sun, Jingwen Sun, Brandon J. Jolly, Martin Riu, Tyler Kerr, Yi-An Lai, Michael J Pung, Chong Liu, Matthew Nava
Proton-coupled electron transfer (PCET) underpins energy conversion processes in biological systems and fuel-forming reactions. Interrogation of the dynamics of electron and proton transfer in PCET processes requires tunable models, with synthetic transition metal aquo complexes being particularly well-explored examples. A previous study on a PCET model, [OsII(bpy)2(py)(OH2)]2+ (bpy = 2,2'-bipyridine; py = pyridine), reported synthetic intractability which limits access to this class of models. Herein, we report an improved protocol to synthesize a family of [OsII(bpy)2(py)(OH2)]2+ complexes enabling the modular tuning of the pyridine ligand with electron-donating or -withdrawing groups on the para-position. The modification of the electron density about the osmium center is reflected in Hammett plots of half-wave peak potential for the OsII/OsIII couples and pKa values of the coordinated water. Moreover, a hydrogen-bonded osmium dimeric structure featuring a short, strong hydrogen bonding network in the solid state was observed; we find the dimeric Os structure is likely not maintained in solution. Our work expands access to osmium aquo complexes and provides a venue to understand how modification of supporting ligands can influence PCET processes.
{"title":"Synthesis of [Os(bpy)2(py)(OH2)](PF6)x Substituted Pyridine Complexes; Characterization of a Singly Bridged H3O2− Ligand","authors":"Jiangtian Sun, Jingwen Sun, Brandon J. Jolly, Martin Riu, Tyler Kerr, Yi-An Lai, Michael J Pung, Chong Liu, Matthew Nava","doi":"10.1039/d5dt00419e","DOIUrl":"https://doi.org/10.1039/d5dt00419e","url":null,"abstract":"Proton-coupled electron transfer (PCET) underpins energy conversion processes in biological systems and fuel-forming reactions. Interrogation of the dynamics of electron and proton transfer in PCET processes requires tunable models, with synthetic transition metal aquo complexes being particularly well-explored examples. A previous study on a PCET model, [Os<small><sup>II</sup></small>(bpy)<small><sub>2</sub></small>(py)(OH<small><sub>2</sub></small>)]<small><sup>2+</sup></small> (bpy = 2,2'-bipyridine; py = pyridine), reported synthetic intractability which limits access to this class of models. Herein, we report an improved protocol to synthesize a family of [Os<small><sup>II</sup></small>(bpy)<small><sub>2</sub></small>(py)(OH<small><sub>2</sub></small>)]<small><sup>2+</sup></small> complexes enabling the modular tuning of the pyridine ligand with electron-donating or -withdrawing groups on the <em>para</em>-position. The modification of the electron density about the osmium center is reflected in Hammett plots of half-wave peak potential for the Os<small><sup>II</sup></small>/Os<small><sup>III</sup></small> couples and pKa values of the coordinated water. Moreover, a hydrogen-bonded osmium dimeric structure featuring a short, strong hydrogen bonding network in the solid state was observed; we find the dimeric Os structure is likely not maintained in solution. Our work expands access to osmium aquo complexes and provides a venue to understand how modification of supporting ligands can influence PCET processes.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"11 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470986","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}
Hanqing Dong, Hongwei Xie, Qiushi Song, Zhiqiang Ning
SiOx is deemed a promising candidate for lithium-ion batteries owing to its high specific capacity and relatively low volume expansion. However, its low rate performance is a bottleneck for its application. Two-dimensional SiOx with short lithium-ion pathways and large layer intervals has been a hot research topic for improving the electrochemical performance of lithium-ion batteries. Herein, a solid exfoliation method was designed to synthesize a multilayer SiOx using CaSi2 and Fe2O3. This multilayer SiOx exhibited large layer intervals after the by-products were removed by HCl. The void space provided extra space for volume expansion, which prevented pulverization, and the thin monolayer shortened the Li+ pathways. Therefore, ML-SiOx–Fe2O3 exhibited an excellent reversible capacity of 697.8 mA h g−1 after 200 cycles at 0.5 A g−1 with a capacity retention of 94.2%. Meanwhile, ML-SiOx–Fe2O3 anode delivered a rate performance of 432.7 mA h g−1 at 3 A g−1, and it could be recovered to 1157.1 mA h g−1 when the current density was converted to 0.1 A g−1. This work opens up a new method for synthesizing multilayer SiOx using metal oxides to exfoliate CaSi2.
{"title":"Multilayer SiOx derived from Si–Ca alloy via Fe2O3 oxidization for Li-ion batteries","authors":"Hanqing Dong, Hongwei Xie, Qiushi Song, Zhiqiang Ning","doi":"10.1039/d4dt03439b","DOIUrl":"https://doi.org/10.1039/d4dt03439b","url":null,"abstract":"SiO<small><sub><em>x</em></sub></small> is deemed a promising candidate for lithium-ion batteries owing to its high specific capacity and relatively low volume expansion. However, its low rate performance is a bottleneck for its application. Two-dimensional SiO<small><sub><em>x</em></sub></small> with short lithium-ion pathways and large layer intervals has been a hot research topic for improving the electrochemical performance of lithium-ion batteries. Herein, a solid exfoliation method was designed to synthesize a multilayer SiO<small><sub><em>x</em></sub></small> using CaSi<small><sub>2</sub></small> and Fe<small><sub>2</sub></small>O<small><sub>3</sub></small>. This multilayer SiO<small><sub><em>x</em></sub></small> exhibited large layer intervals after the by-products were removed by HCl. The void space provided extra space for volume expansion, which prevented pulverization, and the thin monolayer shortened the Li<small><sup>+</sup></small> pathways. Therefore, ML-SiO<small><sub><em>x</em></sub></small>–Fe<small><sub>2</sub></small>O<small><sub>3</sub></small> exhibited an excellent reversible capacity of 697.8 mA h g<small><sup>−1</sup></small> after 200 cycles at 0.5 A g<small><sup>−1</sup></small> with a capacity retention of 94.2%. Meanwhile, ML-SiO<small><sub><em>x</em></sub></small>–Fe<small><sub>2</sub></small>O<small><sub>3</sub></small> anode delivered a rate performance of 432.7 mA h g<small><sup>−1</sup></small> at 3 A g<small><sup>−1</sup></small>, and it could be recovered to 1157.1 mA h g<small><sup>−1</sup></small> when the current density was converted to 0.1 A g<small><sup>−1</sup></small>. This work opens up a new method for synthesizing multilayer SiO<small><sub><em>x</em></sub></small> using metal oxides to exfoliate CaSi<small><sub>2</sub></small>.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"17 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451957","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 advent of nanotechnology has brought tremendous progress in the field of biomedical science and opened avenues for advanced diagnostics and therapeutics applications. Several nanocarriers such as nanoparticles, liposomes, and nanogels have been designed to elevate the drug efficiency and targeting ability in the patient. Nanoparticles based on gold, silver, and iron are dominantly used for biomedical purposes owing to their biocompatibility properties. Nanoparticles offer an enhanced permeation into the tissue vessels; however, their short half-life, toxicity, and off-site accumulations limit their functionality. The above shortcomings could be prevented by employing an integrated system combining nanoparticles with a nanogel-based system. These nanogels are 3D polymeric networks formed by physical and chemical crosslinking and are capable of incorporating nanoparticles, drugs, proteins, and genetic materials. Modification, functionalization, and introduction of inorganic nanoparticles have been shown to enhance the properties of nanogels, such as biocompatibility, stimuli responsiveness, stability, and selectivity. This review paper is focused on the design, synthesis, and biomedical application of inorganic nanoparticle-based nanogels. Current challenges and future perspectives will be briefly discussed to emphasize the versatile role of these multifunctional nanogels for therapeutic and diagnostic purposes.
{"title":"Inorganic nanoparticle-based nanogels and their biomedical applications","authors":"Chanchal Sonkar, Rishi Ranjan, Suman Mukhopadhyay","doi":"10.1039/d4dt02986k","DOIUrl":"https://doi.org/10.1039/d4dt02986k","url":null,"abstract":"The advent of nanotechnology has brought tremendous progress in the field of biomedical science and opened avenues for advanced diagnostics and therapeutics applications. Several nanocarriers such as nanoparticles, liposomes, and nanogels have been designed to elevate the drug efficiency and targeting ability in the patient. Nanoparticles based on gold, silver, and iron are dominantly used for biomedical purposes owing to their biocompatibility properties. Nanoparticles offer an enhanced permeation into the tissue vessels; however, their short half-life, toxicity, and off-site accumulations limit their functionality. The above shortcomings could be prevented by employing an integrated system combining nanoparticles with a nanogel-based system. These nanogels are 3D polymeric networks formed by physical and chemical crosslinking and are capable of incorporating nanoparticles, drugs, proteins, and genetic materials. Modification, functionalization, and introduction of inorganic nanoparticles have been shown to enhance the properties of nanogels, such as biocompatibility, stimuli responsiveness, stability, and selectivity. This review paper is focused on the design, synthesis, and biomedical application of inorganic nanoparticle-based nanogels. Current challenges and future perspectives will be briefly discussed to emphasize the versatile role of these multifunctional nanogels for therapeutic and diagnostic purposes.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"64 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451958","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 Fe based nitrogen-doped carbon oxygen reduction catalysts with high performance have been widely reported, however, the Fenton reaction faced by such catalysts has hindered its practical application in the fuel cell. The development of cheap, effective, and durable non-Fe nitrogen-doped carbon electrocatalysts is important to fuel cell technology. In this work, we have introduced a molecular coordination chemistry method to synthesize Cu and P co-doped nitrogen-doped hierarchical carbon (Cu-P-N-C) oxygen reduction reaction(ORR) electrocatalyst by pyrolyzing a mixture of phytate and melamine. The refined Cu-P-N-C material showcases a three-dimensional, porous, interconnected nanosheet structure with ultra-high specific surface area and an abundance of active sites. The Cu-P-N-C catalyst has displayed a half-wave potential (E1/2) of 0.86 VRHE, which transcends that of commercial Pt/C in 0.1M KOH. It also maintains impressive long-term stability, retaining 95.4% of its initial activity after extensive testing. When integrated into zinc-air batteries (ZABs), the Cu-P-N-C electrocatalyst delivers exceptional performance, achieving a high peak power density of 164.5 mW·cm-2, a promising specific capacity of 807 mAh·g-1, and remarkable stability. These findings underscore the potential of Cu-P-N-C as a potential candidate for next-generation ORR electrocatalysts in new energy devices.
{"title":"Cu and P co-doped nitrogen-doped hierarchical carbon for enhanced oxygen reduction reaction in zinc-air battery","authors":"Zhongyuan Rong, Mengwei Li, Yijie Deng, Haibo Tang","doi":"10.1039/d4dt03156c","DOIUrl":"https://doi.org/10.1039/d4dt03156c","url":null,"abstract":"The Fe based nitrogen-doped carbon oxygen reduction catalysts with high performance have been widely reported, however, the Fenton reaction faced by such catalysts has hindered its practical application in the fuel cell. The development of cheap, effective, and durable non-Fe nitrogen-doped carbon electrocatalysts is important to fuel cell technology. In this work, we have introduced a molecular coordination chemistry method to synthesize Cu and P co-doped nitrogen-doped hierarchical carbon (Cu-P-N-C) oxygen reduction reaction(ORR) electrocatalyst by pyrolyzing a mixture of phytate and melamine. The refined Cu-P-N-C material showcases a three-dimensional, porous, interconnected nanosheet structure with ultra-high specific surface area and an abundance of active sites. The Cu-P-N-C catalyst has displayed a half-wave potential (E1/2) of 0.86 VRHE, which transcends that of commercial Pt/C in 0.1M KOH. It also maintains impressive long-term stability, retaining 95.4% of its initial activity after extensive testing. When integrated into zinc-air batteries (ZABs), the Cu-P-N-C electrocatalyst delivers exceptional performance, achieving a high peak power density of 164.5 mW·cm-2, a promising specific capacity of 807 mAh·g-1, and remarkable stability. These findings underscore the potential of Cu-P-N-C as a potential candidate for next-generation ORR electrocatalysts in new energy devices.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"20 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451959","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}
Na3V2(PO4)3 (NVP) suffers from poor ionic and electronic conductivity. Herein, a dual-optimized design with Cu2+ doping and wrapping in tubular carbon nanotubes (CNTs) is proposed for the first time. This strategy not only modifies the internal electronic structure but also regulates the morphological features of NVP material. Notably, Cu2+ occupying V3+ sites introduces favorable p-type doping effects. Consequently, newly generated holes can act as charge carriers to improve electronic conductivity. Meanwhile, to conserve the charge balance of the whole system, a series of distinctive Na3+xV2−xCux(PO4)3 cathode materials are designed. The Na-rich scheme maintains charge integrity, as well as supplying more active Na+ to take part in the reversible de-intercalation process. Due to the larger ionic radius of Cu2+, Cu2+ doping plays a great role as a pillar to support the crystal skeleton and then expand the Na+ migration channels, thus significantly elevating the ionic transport rate. Furthermore, moderate CNTs are wrapped around the active grains, functioning together with coated carbon layers to construct a highly conductive framework, enhancing electronic transfer. Meanwhile, the tubular CNTs and porous morphology effectively increase the contact areas between active particles and electrolyte, providing more active sites. Furthermore, in situ EIS measurement demonstrates that a stable SEI membrane covers the cycled Na3.07V1.93Cu0.07(PO4)3@CNTs grains to maintain electrode stability and prevent the occurrence of side-effects. Comprehensively, the Na3.07V1.93Cu0.07(PO4)3@CNTs sample releases 124.2 mA h g−1 at 0.1 C. It releases 101.9 and 98.6 mA h g−1 at 10 and 50 C, suggesting superior rate capability.
{"title":"Cu2+ substitution regulating Na3V2(PO4)3 with solid SEI membrane for superior electrochemical performance","authors":"Zhenbo Peng, Bifen Chen, Shan Yu, Kaiyu Wu, Farao Zhang, Peng Gao","doi":"10.1039/d4dt03559c","DOIUrl":"https://doi.org/10.1039/d4dt03559c","url":null,"abstract":"Na<small><sub>3</sub></small>V<small><sub>2</sub></small>(PO<small><sub>4</sub></small>)<small><sub>3</sub></small> (NVP) suffers from poor ionic and electronic conductivity. Herein, a dual-optimized design with Cu<small><sup>2+</sup></small> doping and wrapping in tubular carbon nanotubes (CNTs) is proposed for the first time. This strategy not only modifies the internal electronic structure but also regulates the morphological features of NVP material. Notably, Cu<small><sup>2+</sup></small> occupying V<small><sup>3+</sup></small> sites introduces favorable p-type doping effects. Consequently, newly generated holes can act as charge carriers to improve electronic conductivity. Meanwhile, to conserve the charge balance of the whole system, a series of distinctive Na<small><sub>3+<em>x</em></sub></small>V<small><sub>2−<em>x</em></sub></small>Cu<small><sub><em>x</em></sub></small>(PO<small><sub>4</sub></small>)<small><sub>3</sub></small> cathode materials are designed. The Na-rich scheme maintains charge integrity, as well as supplying more active Na<small><sup>+</sup></small> to take part in the reversible de-intercalation process. Due to the larger ionic radius of Cu<small><sup>2+</sup></small>, Cu<small><sup>2+</sup></small> doping plays a great role as a pillar to support the crystal skeleton and then expand the Na<small><sup>+</sup></small> migration channels, thus significantly elevating the ionic transport rate. Furthermore, moderate CNTs are wrapped around the active grains, functioning together with coated carbon layers to construct a highly conductive framework, enhancing electronic transfer. Meanwhile, the tubular CNTs and porous morphology effectively increase the contact areas between active particles and electrolyte, providing more active sites. Furthermore, <em>in situ</em> EIS measurement demonstrates that a stable SEI membrane covers the cycled Na<small><sub>3.07</sub></small>V<small><sub>1.93</sub></small>Cu<small><sub>0.07</sub></small>(PO<small><sub>4</sub></small>)<small><sub>3</sub></small>@CNTs grains to maintain electrode stability and prevent the occurrence of side-effects. Comprehensively, the Na<small><sub>3.07</sub></small>V<small><sub>1.93</sub></small>Cu<small><sub>0.07</sub></small>(PO<small><sub>4</sub></small>)<small><sub>3</sub></small>@CNTs sample releases 124.2 mA h g<small><sup>−1</sup></small> at 0.1 C. It releases 101.9 and 98.6 mA h g<small><sup>−1</sup></small> at 10 and 50 C, suggesting superior rate capability.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"736 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443769","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}
We present an investigation of the prototypical polymorphic structural transformation from marcasite to pyrite FeS2 studied by combining annealing experiments and theoretical calculations. These experiments have become possible due to the availability of laboratory-synthesized high-purity marcasite samples. We constructed an annealing temperature, time, and phase composition map of marcasite based on a series of isothermal annealing experiments at different temperatures and heating times. To understand the microscopic mechanisms and pathways of the transformation, we performed theoretical calculations that yield an agreement with the experimental results. Based on the combined results, we show that the transformation of marcasite to pyrite, while thermodynamically favorable, is hindered by a kinetic barrier of the order of 3 eV. As a result, marcasite can remain stable for extended times at temperatures below 450 °C.
{"title":"A combined experimental and theoretical study of the prototypical polymorphic transformation from marcasite to pyrite FeS2","authors":"KeYuan Ma, Ulrich Aschauer, Fabian O. von Rohr","doi":"10.1039/d4dt03447c","DOIUrl":"https://doi.org/10.1039/d4dt03447c","url":null,"abstract":"We present an investigation of the prototypical polymorphic structural transformation from marcasite to pyrite FeS<small><sub>2</sub></small> studied by combining annealing experiments and theoretical calculations. These experiments have become possible due to the availability of laboratory-synthesized high-purity marcasite samples. We constructed an annealing temperature, time, and phase composition map of marcasite based on a series of isothermal annealing experiments at different temperatures and heating times. To understand the microscopic mechanisms and pathways of the transformation, we performed theoretical calculations that yield an agreement with the experimental results. Based on the combined results, we show that the transformation of marcasite to pyrite, while thermodynamically favorable, is hindered by a kinetic barrier of the order of 3 eV. As a result, marcasite can remain stable for extended times at temperatures below 450 °C.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"13 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143443770","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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