Improving the selectivity of the electrocatalytic CO_(2) reduction reaction(CO_(2)RR)over hydrogen evolution in aqueous solutions is required but challenging because the two reactions occur at close thermodynamic pote...Improving the selectivity of the electrocatalytic CO_(2) reduction reaction(CO_(2)RR)over hydrogen evolution in aqueous solutions is required but challenging because the two reactions occur at close thermodynamic potentials and compete with each other.Herein,we report on the selective CO_(2)RR in aqueous solutions utilizing covalent Co porphyrin polymers with fine-tuned electronic structures.展开更多
Photoluminescence properties and exciton decay dynamics in a porphyrin side-chain polymer, poly[porphyrin acrylate- acrylonitrile （abbreviated p[（por）A-AN]）, have been investigated by femtosecond time-resolved pho...Photoluminescence properties and exciton decay dynamics in a porphyrin side-chain polymer, poly[porphyrin acrylate- acrylonitrile （abbreviated p[（por）A-AN]）, have been investigated by femtosecond time-resolved photoluminescence spectroscopy. All the luminescences of p[（por）A-AN] films are due to the emissive decay of the photoexcited singlet excitons in the porphyrins. The luminescence efficiencies and lifetimes are increased for samples from pure films to dilute blend films. However, they are increased as the intrachain concentration of the porphyrin sidechain groups is decreased. The intrachain rotation motions of porphyrin sidechain groups result in the initial ultrafast luminescence decays, which are much faster than those due to the interchain interactions. All the samples show no significant red-shift and broadening of the transient luminescence spectra. The interchain and intrachain nonradiative exciton relaxation processes may play an important role in the luminescence dynamics in the p[（por）A-AN] films. The possible origin of different intrachain and interchain dynamic behaviours in p[（por）A-AN] films is discussed.展开更多
Inhibiting the ions migration and even irreversible reactions have been regarded as one of the most important factors for fabricating efficient and stable perovskite solar cells(PSCs).Here,we employed the diamine coba...Inhibiting the ions migration and even irreversible reactions have been regarded as one of the most important factors for fabricating efficient and stable perovskite solar cells(PSCs).Here,we employed the diamine cobalt(II)porphyrin[Co(II)P]to treat a perovskite film to construct in situ Co(II)P-based coordination polymer on the perovskite film.The crystal structure of the polymer indicated a central cobalt(Co)ion in one Co(II)P coordinated with two amine units from a different neighboring Co(II)P to form an overall three-dimensional(3D)structure.Such a 3D network covered on the perovskite surface could prevent the migration of ions from the perovskite.Furthermore,the limited amount of diatomic iodine(I2)released in the perovskite due to iodide oxidation defects could be reduced to I–by the Co(II)ion in the polymer,and thus,achieve regeneration.Finally,the Co(Ⅱ/Ⅲ)ion pair formed in the polymer facilitated the charge transfer and boosted to the best efficiency up to 21.3%.Remarkably improved cell stability under moisture,heating,or light was also achieved.The control PSCs with Zn-based 3D polymer and Co-based 1D polymer exhibited the poor cell efficiencies and stabilities than those of the 3D Co porphyrin-based PSC to verify the effect of 3D Co porphyrin-based polymer in stabilizing the perovskite film.This work provides a new encapsulation and regeneration strategy via in situ construction of a Co(Ⅱ)porphyrin-based coordination polymer on perovskite film for efficient and stable PSCs.展开更多
基金support from the National Natural Science Foundation of China(nos.21773146 and 22003036)the Fok Ying-Tong Education Foundation for Outstanding Young Teachers in Universitythe Fundamental Research Funds for the Central Universities,and the Research Funds of Shaanxi Normal University(nos.2020CBLZ005,GK202103045,and GK202103033).U.-P.A.thanks the Fraunhofer Internal Programs for their support under Grant No.Attract 097-602175 and the DFG under Germany’s Excellence Strategy—EXC-2033—Projektnummer 390677874“RESOLV”.
文摘Improving the selectivity of the electrocatalytic CO_(2) reduction reaction(CO_(2)RR)over hydrogen evolution in aqueous solutions is required but challenging because the two reactions occur at close thermodynamic potentials and compete with each other.Herein,we report on the selective CO_(2)RR in aqueous solutions utilizing covalent Co porphyrin polymers with fine-tuned electronic structures.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60478013, 20571089 and 10274107）, the Natural Science Foundation of Guangdong Province, China （Grant No 05101819）, and the Doctoral Program Foundation of Institute of Higher Education of China（Grant No 20040558031）.
文摘Photoluminescence properties and exciton decay dynamics in a porphyrin side-chain polymer, poly[porphyrin acrylate- acrylonitrile （abbreviated p[（por）A-AN]）, have been investigated by femtosecond time-resolved photoluminescence spectroscopy. All the luminescences of p[（por）A-AN] films are due to the emissive decay of the photoexcited singlet excitons in the porphyrins. The luminescence efficiencies and lifetimes are increased for samples from pure films to dilute blend films. However, they are increased as the intrachain concentration of the porphyrin sidechain groups is decreased. The intrachain rotation motions of porphyrin sidechain groups result in the initial ultrafast luminescence decays, which are much faster than those due to the interchain interactions. All the samples show no significant red-shift and broadening of the transient luminescence spectra. The interchain and intrachain nonradiative exciton relaxation processes may play an important role in the luminescence dynamics in the p[（por）A-AN] films. The possible origin of different intrachain and interchain dynamic behaviours in p[（por）A-AN] films is discussed.
基金The authors acknowledge the National Natural Science Foundation of China(21801104 and 21871121)Young Elite Scientists Sponsorship Program by CAST(2018QNRC001)+1 种基金Fundamental Research Funds for the Central Universities(lzujbky-2019-sp01)Special Fund Project of Guiding Scientific and Technological Innovation Development of Gansu Province(2019ZX-04).
文摘Inhibiting the ions migration and even irreversible reactions have been regarded as one of the most important factors for fabricating efficient and stable perovskite solar cells(PSCs).Here,we employed the diamine cobalt(II)porphyrin[Co(II)P]to treat a perovskite film to construct in situ Co(II)P-based coordination polymer on the perovskite film.The crystal structure of the polymer indicated a central cobalt(Co)ion in one Co(II)P coordinated with two amine units from a different neighboring Co(II)P to form an overall three-dimensional(3D)structure.Such a 3D network covered on the perovskite surface could prevent the migration of ions from the perovskite.Furthermore,the limited amount of diatomic iodine(I2)released in the perovskite due to iodide oxidation defects could be reduced to I–by the Co(II)ion in the polymer,and thus,achieve regeneration.Finally,the Co(Ⅱ/Ⅲ)ion pair formed in the polymer facilitated the charge transfer and boosted to the best efficiency up to 21.3%.Remarkably improved cell stability under moisture,heating,or light was also achieved.The control PSCs with Zn-based 3D polymer and Co-based 1D polymer exhibited the poor cell efficiencies and stabilities than those of the 3D Co porphyrin-based PSC to verify the effect of 3D Co porphyrin-based polymer in stabilizing the perovskite film.This work provides a new encapsulation and regeneration strategy via in situ construction of a Co(Ⅱ)porphyrin-based coordination polymer on perovskite film for efficient and stable PSCs.
