In conjugated polymers(CPs)photocatalytic system,the generation of reactive oxygen species(ROS)is regulated by cross-scale factors involving active site,excitonic behavior,and O_(2)activation process on the surface.Ho...In conjugated polymers(CPs)photocatalytic system,the generation of reactive oxygen species(ROS)is regulated by cross-scale factors involving active site,excitonic behavior,and O_(2)activation process on the surface.However,research on exploring the domino effect of“structure→excitonic behavior→O_(2)activation→photocatalytic reaction”through structural modification at the atomic scale remains at its early stages.Herein,two heptazine-based CPs,CP-DPA,and CP-CZ were successfully prepared by polymerization of precursors formed by reacting diphenylamine(DPA)and carbazole(CZ)with cyameluric chloride,respectively.The minute difference in single bond between DPA and CZ endows the polymers with distinct physicochemical properties.Owing to the rotation between benzene rings,CP-DPA exhibits relatively lower conjugation,resulting in increased exciton binding energy(Eb)and inhibited exciton dissociation.Meanwhile,its more triplet state excitons facilitate energy transfer to generate singlet oxygen.Therefore,CP-DPA shows excellent activity for phenylboronic acid oxidation.Conversely,CP-CZ possesses relatively higher conjugation,minimal Eb and intensified exciton dissociation,which promotes charge transfer to produce superoxide radical.Consequently,CP-CZ displays optimal activity for phe-nylacetylene oxidation and[3+2]cycloaddition.This work provides new insights into regulating ROS gener-ation by modulating the composition and structure of photocatalysts at the atomic scale.展开更多
2024年5月10日,地球空间暴发了近20年来最强的磁暴,伴随多次超强亚暴,北京、阿勒泰等地出现罕见极光.磁暴和亚暴是典型的太阳风–磁层耦合暴发模式,是空间天气预报背后的关键科学问题.本文回顾了磁暴和亚暴研究的最新进展,涵盖磁层对流...2024年5月10日,地球空间暴发了近20年来最强的磁暴,伴随多次超强亚暴,北京、阿勒泰等地出现罕见极光.磁暴和亚暴是典型的太阳风–磁层耦合暴发模式,是空间天气预报背后的关键科学问题.本文回顾了磁暴和亚暴研究的最新进展,涵盖磁层对流、磁重联、电流体系、极光活动和高能粒子等主要过程,指出这些过程的跨区域耦合机制及磁暴–亚暴之间的内在联系仍是未解的前沿难题.借鉴地幔对流驱动板块运动、大气对流引发极端天气等类比,本文提出以“磁层对流演化”为核心的未来研究框架.核心假说认为:磁力线在磁层对流驱动下重构空间电流体系,进而主导磁暴与亚暴的发生与演化.该框架目标是统一磁暴-亚暴的内在物理过程,揭示两者的内在联系.围绕该假说,本文提出三个关键科学问题:(1)亚暴期间磁层对流演化特征及其电流体系响应;(2)磁暴期间磁层对流演化特征及其电流体系的响应;(3)磁暴-亚暴对流间的内在联系.在此框架下,本文初步探讨了2024年5月极端磁暴中低纬极光的可能成因,认为其或源于超强磁层对流驱动下的场向电流系统在电离层向赤道大幅度扩展.目前,磁层对流演化的系统研究仍处于初级阶段.即将开展的SMILE(Solar wind Magnetosphere Ionosphere Link Explorer,太阳风-磁层相互作用全景成像卫星)任务与未来的多尺度磁层星座探测计划(self-Adaptive Magnetic reconnection Explorer, AME)将为该方向提供关键观测支撑,推动磁暴-亚暴理论的发展.展开更多
We construct a natural-artificial hybrid architecture containing black phosphorus nanosheets(BPNS)to enhance photosynthesis of chloroplast in a positive-feedback manner.In this architecture,oxygen yielded by photosynt...We construct a natural-artificial hybrid architecture containing black phosphorus nanosheets(BPNS)to enhance photosynthesis of chloroplast in a positive-feedback manner.In this architecture,oxygen yielded by photosynthesis during water splitting by photosystemⅡpromotes the photoreaction of BPNS to produce proton and inorganic phosphate(Pi).Further,transmembrane proton gradient is increased to drive ATP synthase to synthesize ATP.Meanwhile,additional photogenerated electrons produced by BPNS are transferred to the photosynthesis process.As a consequence,photosynthesis performed by chloroplast is improved.Quantitatively,photophosphorylation efficacy of the hybrid system is increased by 1.89 times in the case of Pi deficiency.This work offers a new path to enhance solar-to-chemical energy conversion,holding promise in boosting natural photosynthesis.展开更多
Herein,we couple a synthetic electrozyme in a supramolecule-assembled nanoarchitecture to achieve enhanced bioenergy transformation by mimicking mitochondrial oxidative phosphorylation.Different from the natural count...Herein,we couple a synthetic electrozyme in a supramolecule-assembled nanoarchitecture to achieve enhanced bioenergy transformation by mimicking mitochondrial oxidative phosphorylation.Different from the natural counterpart,the metal-free electrozyme is a semiconducting polymer deposited on an electrode.The wellmatched electrocatalytic property of the electrozyme permits oxidization of reduced nicotinamide adenine dinucleotide(NADH)to release protons under a much lower electric potential.As a consequence,the generated proton gradient drives rotary catalysis of adenosine 5′-triphosphate(ATP)synthase reconstituted in a lipid membrane to produce ATP.Remarkably,electrochemical bioenergy conversion of NADH to ATP is accomplished with much higher efficiency in such a bio-like system compared with the natural mitochondria.This work integrates synthetic and natural catalytic chemistry to facilitate enhanced bioenergy transformation,thereby greatly improving prospects in ATP-fueled bioapplications.展开更多
Increasing the length of alkyl side chains is a typical way to improve the solubility ofπ-conjugated polymers designed for use in solution-processed devices.However,these modifications have also been reported to alte...Increasing the length of alkyl side chains is a typical way to improve the solubility ofπ-conjugated polymers designed for use in solution-processed devices.However,these modifications have also been reported to alter the film morphology.Given that the mechanism leading to improved solubility is not well documented yet and the nanoscale(local)morphologies of amorphousπ-conjugated polymer films are difficult to characterize experimentally,here,we combine molecular dynamics simulations and long-range corrected density functional theory calculations to examine at the molecular scale the impact that the alkyl side-chain length has on polymer solubility and film morphologies.As a representative example,we consider poly(thieno[3,4-c]pyrrole-4,6-dione-alt-3,4-difluorothiophene)(PTPD[2F]T)with two different lengths of the alkyl side chains on the thieno[3,4-c]pyrrole-4,6-dione(TPD)moieties,i.e.,2-hexyldecyl(2HD)and 2-decyltetradecyl(2DT).A detailed analysis of polymer–solvent and polymer–polymer interactions provides a picture that describes the underlying mechanism for improved solubility in going from 2HD to 2DT.We then underline an intrinsic characteristic that decreasing the side-chain length brings a greater extent of backbone planarity and lesser side chain-TPD interactions,which leads to higher interchainπ-πpacking density and order,while the interchainπ-πpacking patterns remain similar in the two films.These morphologies are discussed in terms of the charge-transport properties between neighboring PTPD[2F]T chains,which point to a higher electron mobility in the PTPD[2F]T films with shorter alkyl side chains.Overall,our findings offer guidance in the field of solution-processed electronic devices by pointing out that the polymer alkyl side-chain length could be minimized to improve carrier mobility while ensuring polymer solubility.展开更多
基金supported by National Natural Science Foundation of China(22171041,22071020,52130101)National Key R&D Program of China(2023YFB3003001)+2 种基金Natural Science Foundation of Jilin Province Science and Technology Department(discipline layout project)(grant no.20230508094RC)the Fundamental Research Funds for the Central Universities(grant no.2412021QD008)the Fundamental Research Funds for the Central Universities-Excellent Youth Team Program(2412023YQ001).
文摘In conjugated polymers(CPs)photocatalytic system,the generation of reactive oxygen species(ROS)is regulated by cross-scale factors involving active site,excitonic behavior,and O_(2)activation process on the surface.However,research on exploring the domino effect of“structure→excitonic behavior→O_(2)activation→photocatalytic reaction”through structural modification at the atomic scale remains at its early stages.Herein,two heptazine-based CPs,CP-DPA,and CP-CZ were successfully prepared by polymerization of precursors formed by reacting diphenylamine(DPA)and carbazole(CZ)with cyameluric chloride,respectively.The minute difference in single bond between DPA and CZ endows the polymers with distinct physicochemical properties.Owing to the rotation between benzene rings,CP-DPA exhibits relatively lower conjugation,resulting in increased exciton binding energy(Eb)and inhibited exciton dissociation.Meanwhile,its more triplet state excitons facilitate energy transfer to generate singlet oxygen.Therefore,CP-DPA shows excellent activity for phenylboronic acid oxidation.Conversely,CP-CZ possesses relatively higher conjugation,minimal Eb and intensified exciton dissociation,which promotes charge transfer to produce superoxide radical.Consequently,CP-CZ displays optimal activity for phe-nylacetylene oxidation and[3+2]cycloaddition.This work provides new insights into regulating ROS gener-ation by modulating the composition and structure of photocatalysts at the atomic scale.
文摘2024年5月10日,地球空间暴发了近20年来最强的磁暴,伴随多次超强亚暴,北京、阿勒泰等地出现罕见极光.磁暴和亚暴是典型的太阳风–磁层耦合暴发模式,是空间天气预报背后的关键科学问题.本文回顾了磁暴和亚暴研究的最新进展,涵盖磁层对流、磁重联、电流体系、极光活动和高能粒子等主要过程,指出这些过程的跨区域耦合机制及磁暴–亚暴之间的内在联系仍是未解的前沿难题.借鉴地幔对流驱动板块运动、大气对流引发极端天气等类比,本文提出以“磁层对流演化”为核心的未来研究框架.核心假说认为:磁力线在磁层对流驱动下重构空间电流体系,进而主导磁暴与亚暴的发生与演化.该框架目标是统一磁暴-亚暴的内在物理过程,揭示两者的内在联系.围绕该假说,本文提出三个关键科学问题:(1)亚暴期间磁层对流演化特征及其电流体系响应;(2)磁暴期间磁层对流演化特征及其电流体系的响应;(3)磁暴-亚暴对流间的内在联系.在此框架下,本文初步探讨了2024年5月极端磁暴中低纬极光的可能成因,认为其或源于超强磁层对流驱动下的场向电流系统在电离层向赤道大幅度扩展.目前,磁层对流演化的系统研究仍处于初级阶段.即将开展的SMILE(Solar wind Magnetosphere Ionosphere Link Explorer,太阳风-磁层相互作用全景成像卫星)任务与未来的多尺度磁层星座探测计划(self-Adaptive Magnetic reconnection Explorer, AME)将为该方向提供关键观测支撑,推动磁暴-亚暴理论的发展.
基金the financial support for this research from the National Natural Science Foundation of China(Nos.221930301,21961142022,21872150,and 22072160)J.F.particularly thanks to the Youth Innovation Promotion Association of CAS(No.2016032)Instituteof Chemistry,CAS(No.Y6290512B1).
文摘We construct a natural-artificial hybrid architecture containing black phosphorus nanosheets(BPNS)to enhance photosynthesis of chloroplast in a positive-feedback manner.In this architecture,oxygen yielded by photosynthesis during water splitting by photosystemⅡpromotes the photoreaction of BPNS to produce proton and inorganic phosphate(Pi).Further,transmembrane proton gradient is increased to drive ATP synthase to synthesize ATP.Meanwhile,additional photogenerated electrons produced by BPNS are transferred to the photosynthesis process.As a consequence,photosynthesis performed by chloroplast is improved.Quantitatively,photophosphorylation efficacy of the hybrid system is increased by 1.89 times in the case of Pi deficiency.This work offers a new path to enhance solar-to-chemical energy conversion,holding promise in boosting natural photosynthesis.
基金This work was supported by the NationalNatural Science Foundation of China(grant nos.221930301,21961142022,22072160,and 21872150).J.F.particularly thanks to Institute of Chemistry,CAS(grant no.Y6290512B1).
文摘Herein,we couple a synthetic electrozyme in a supramolecule-assembled nanoarchitecture to achieve enhanced bioenergy transformation by mimicking mitochondrial oxidative phosphorylation.Different from the natural counterpart,the metal-free electrozyme is a semiconducting polymer deposited on an electrode.The wellmatched electrocatalytic property of the electrozyme permits oxidization of reduced nicotinamide adenine dinucleotide(NADH)to release protons under a much lower electric potential.As a consequence,the generated proton gradient drives rotary catalysis of adenosine 5′-triphosphate(ATP)synthase reconstituted in a lipid membrane to produce ATP.Remarkably,electrochemical bioenergy conversion of NADH to ATP is accomplished with much higher efficiency in such a bio-like system compared with the natural mitochondria.This work integrates synthetic and natural catalytic chemistry to facilitate enhanced bioenergy transformation,thereby greatly improving prospects in ATP-fueled bioapplications.
基金supported by the National Key R&D Program of China(No.2023YFB3003001)National Natural Science Foundation of China(No.52130101)“Xiaomi Young Scholar”Project,and the fund of“World-class Universities and World-class Disciplines”,Ministry of Education,China.The work at Arizona was funded by the Office of Naval Research(No.N00014-24-1-2114).
文摘Increasing the length of alkyl side chains is a typical way to improve the solubility ofπ-conjugated polymers designed for use in solution-processed devices.However,these modifications have also been reported to alter the film morphology.Given that the mechanism leading to improved solubility is not well documented yet and the nanoscale(local)morphologies of amorphousπ-conjugated polymer films are difficult to characterize experimentally,here,we combine molecular dynamics simulations and long-range corrected density functional theory calculations to examine at the molecular scale the impact that the alkyl side-chain length has on polymer solubility and film morphologies.As a representative example,we consider poly(thieno[3,4-c]pyrrole-4,6-dione-alt-3,4-difluorothiophene)(PTPD[2F]T)with two different lengths of the alkyl side chains on the thieno[3,4-c]pyrrole-4,6-dione(TPD)moieties,i.e.,2-hexyldecyl(2HD)and 2-decyltetradecyl(2DT).A detailed analysis of polymer–solvent and polymer–polymer interactions provides a picture that describes the underlying mechanism for improved solubility in going from 2HD to 2DT.We then underline an intrinsic characteristic that decreasing the side-chain length brings a greater extent of backbone planarity and lesser side chain-TPD interactions,which leads to higher interchainπ-πpacking density and order,while the interchainπ-πpacking patterns remain similar in the two films.These morphologies are discussed in terms of the charge-transport properties between neighboring PTPD[2F]T chains,which point to a higher electron mobility in the PTPD[2F]T films with shorter alkyl side chains.Overall,our findings offer guidance in the field of solution-processed electronic devices by pointing out that the polymer alkyl side-chain length could be minimized to improve carrier mobility while ensuring polymer solubility.
