Photocatalysis opens unique pathways for reductive hydrogenation under mild conditions.Typically,photocatalytic hydrogenation proceeds via single electron transfer(SET),followed by hydrogen atom transfer.Herein,we elu...Photocatalysis opens unique pathways for reductive hydrogenation under mild conditions.Typically,photocatalytic hydrogenation proceeds via single electron transfer(SET),followed by hydrogen atom transfer.Herein,we elucidate that the deliberate arrangement of an electron reservoir and Ni catalysts enables a transition from photoinduced one-to twoelectron transfer,yielding desired products via proton acquisition.Specifically,arranging carbon nitride(CN)that stores multiple photogenerated electrons in proximity to a chemically bonded Ni site accomplishes competitive two-electron/proton hydrogenation of halogenated substrates using water as the hydrogen source,outperforming the SETmediated process.In contrast,the nonchemically bonded Ni and CN system exhibits poor activity for 2e−/H+hydrogenation.Mechanistic studies further reveal that the low-valent Ni+and CN(e−)cooperate to transfer two electrons to the substrate.The catalytic utility of this two-electron mechanism is further underscored by the deuterium labeling of diverse(hetero)arenes and bioactive molecules in D_(2)O,achieving deuterium incorporation of up to 99%.Our work highlights the value of light-driven multipleelectron catalysis that reaches otherwise challenging transformations.展开更多
Prussian blue analogs(PBAs)are potential contestants for aqueous Mg-ion batteries(AMIBs)on account of their high discharge voltage and threedimensional open frameworks.However,the low capacity arising from single reac...Prussian blue analogs(PBAs)are potential contestants for aqueous Mg-ion batteries(AMIBs)on account of their high discharge voltage and threedimensional open frameworks.However,the low capacity arising from single reaction site severely restricts PBAs'practical applications in highenergy-density AMIBs.Here,an organic acid co-coordination combined with etching method is reported to fabricate defect-rich potassium-free copper hexacyanoferrate with structural water on carbon nanotube fiber(DCuHCF@CNTF).Benefiting from the high-valence-state reactive sites,arrayed structure and defect effect,the well-designed D-CuHCF@CNTF exhibits an extraordinary reversible capacity of 146.6 mAh g1 with two-electron reaction,nearly close to its theoretical capacity.It is interesting to unlock the reaction mechanism of the Fe2+/Fe3+and Cu+/Cu2+redox couples via x-ray photoelectron spectroscopy.Furthermore,density functional theory calculations reveal that Fe and Cu in potassium-free D-CuHCF participate in charge transfer during the Mg2+insertion/extraction process.As a proof-of-concept demonstration,a rocking-chair fiber-shaped AMIBs was constructed via coupling with the NaTi2(PO4)3/CNTF anode,achieving high energy density and impressive mechanical flexibility.This work provides new possibilities to develop potassium-free PBAs with dual-active sites as high-capacity cathodes for wearable AMIBs.展开更多
Two-electron neutral aqueous organic redox flow batteries(AORFBs)hold more promising applications in the power grid than one-electron batteries because of their higher capacity.However,their development is strongly li...Two-electron neutral aqueous organic redox flow batteries(AORFBs)hold more promising applications in the power grid than one-electron batteries because of their higher capacity.However,their development is strongly limited by the structural instability of the highly reduced species.By combining the extendedπ-conjugation structure of the anolytes and the enhanced aromaticity of the highly reduced species,we reported a series of highly conjugated and inexpensive arylene diimide derivatives(NDI,PDI,and TPDI)as novel two-electron storage anolyte materials for ultrastable AORFBs.Matched with(ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte,arylene diimide derivative-based AORFBs showed the highest stability in two-electron AORFBs to date.The NDI/FcNCl-based AORFB delivered 98.44%capacity retention at 40 mA cm^(−2)for 350 cycles;TPDI/FcNCl-based AORFB also showed remarkable stability with 97.22%capacity retention at 20 mA cm^(−2)over 200 cycles.This finding lays the theoretical foundation and offers a reference for improving the stability of two-electron AORFBs.展开更多
基金the following agencies for financially supporting this work:the National Key Research and Development Program of China(grant no.2024YFA1211000)the National Natural Science Foundation of China(grant nos.22321004 and 22273111).
文摘Photocatalysis opens unique pathways for reductive hydrogenation under mild conditions.Typically,photocatalytic hydrogenation proceeds via single electron transfer(SET),followed by hydrogen atom transfer.Herein,we elucidate that the deliberate arrangement of an electron reservoir and Ni catalysts enables a transition from photoinduced one-to twoelectron transfer,yielding desired products via proton acquisition.Specifically,arranging carbon nitride(CN)that stores multiple photogenerated electrons in proximity to a chemically bonded Ni site accomplishes competitive two-electron/proton hydrogenation of halogenated substrates using water as the hydrogen source,outperforming the SETmediated process.In contrast,the nonchemically bonded Ni and CN system exhibits poor activity for 2e−/H+hydrogenation.Mechanistic studies further reveal that the low-valent Ni+and CN(e−)cooperate to transfer two electrons to the substrate.The catalytic utility of this two-electron mechanism is further underscored by the deuterium labeling of diverse(hetero)arenes and bioactive molecules in D_(2)O,achieving deuterium incorporation of up to 99%.Our work highlights the value of light-driven multipleelectron catalysis that reaches otherwise challenging transformations.
基金National Key R&D Program of China,Grant/Award Number:2022YFA1203304Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20220288Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Grant/Award Number:E1552102。
文摘Prussian blue analogs(PBAs)are potential contestants for aqueous Mg-ion batteries(AMIBs)on account of their high discharge voltage and threedimensional open frameworks.However,the low capacity arising from single reaction site severely restricts PBAs'practical applications in highenergy-density AMIBs.Here,an organic acid co-coordination combined with etching method is reported to fabricate defect-rich potassium-free copper hexacyanoferrate with structural water on carbon nanotube fiber(DCuHCF@CNTF).Benefiting from the high-valence-state reactive sites,arrayed structure and defect effect,the well-designed D-CuHCF@CNTF exhibits an extraordinary reversible capacity of 146.6 mAh g1 with two-electron reaction,nearly close to its theoretical capacity.It is interesting to unlock the reaction mechanism of the Fe2+/Fe3+and Cu+/Cu2+redox couples via x-ray photoelectron spectroscopy.Furthermore,density functional theory calculations reveal that Fe and Cu in potassium-free D-CuHCF participate in charge transfer during the Mg2+insertion/extraction process.As a proof-of-concept demonstration,a rocking-chair fiber-shaped AMIBs was constructed via coupling with the NaTi2(PO4)3/CNTF anode,achieving high energy density and impressive mechanical flexibility.This work provides new possibilities to develop potassium-free PBAs with dual-active sites as high-capacity cathodes for wearable AMIBs.
基金supported by the Natural Science Foundation of China(grant nos.22175138 and 21875180)the National Key Research and Development Program of China(grant no.2021YFB3200700)+4 种基金the Key Research and Development Program of Shaanxi(grant no.2021GXLH-Z023)the Independent Innovation Capability Improvement Project of Xi’an Jiaotong University(grant no.PY3A066)the Fundamental Research Funds for the Central Universities(grant no.xhj032021008-03)the Regional Innovation Capability Guidance Program of Shaanxi Province the Fundamental(grant no.2022QFY08-01)the Research Funds for the Central Universities(grant no.xzy022022001).
文摘Two-electron neutral aqueous organic redox flow batteries(AORFBs)hold more promising applications in the power grid than one-electron batteries because of their higher capacity.However,their development is strongly limited by the structural instability of the highly reduced species.By combining the extendedπ-conjugation structure of the anolytes and the enhanced aromaticity of the highly reduced species,we reported a series of highly conjugated and inexpensive arylene diimide derivatives(NDI,PDI,and TPDI)as novel two-electron storage anolyte materials for ultrastable AORFBs.Matched with(ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte,arylene diimide derivative-based AORFBs showed the highest stability in two-electron AORFBs to date.The NDI/FcNCl-based AORFB delivered 98.44%capacity retention at 40 mA cm^(−2)for 350 cycles;TPDI/FcNCl-based AORFB also showed remarkable stability with 97.22%capacity retention at 20 mA cm^(−2)over 200 cycles.This finding lays the theoretical foundation and offers a reference for improving the stability of two-electron AORFBs.
